Letter frequency
You are encouraged to solve this task according to the task description, using any language you may know.
- Task
Open a text file and count the occurrences of each letter.
Some of these programs count all characters (including punctuation),
but some only count letters A to Z.
ACL2
<lang Lisp>(defun increment-alist (tbl key)
(cond ((endp tbl) (list (cons key 1)))
((eql (car (first tbl)) key)
(cons (cons key (1+ (cdr (first tbl))))
(rest tbl)))
(t (cons (first tbl)
(increment-alist (rest tbl) key)))))
(defun freq-table (xs)
(if (endp xs)
nil
(increment-alist (freq-table (rest xs))
(first xs))))
(defun letter-freq (str)
(freq-table (coerce str 'list)))</lang>
Ada
<lang Ada>with Ada.Text_IO;
procedure Letter_Frequency is
Counters: array (Character) of Natural := (others => 0); -- initialize all Counters to 0 C: Character; File: Ada.Text_IO.File_Type;
begin
Ada.Text_IO.Open(File, Mode => Ada.Text_IO.In_File, Name => "letter_frequency.adb");
while not Ada.Text_IO.End_Of_File(File) loop
Ada.Text_IO.Get(File, C);
Counters(C) := Counters(C) + 1;
end loop;
for I in Counters'Range loop
if Counters(I) > 0 then
Ada.Text_IO.Put_Line("'" & I & "':" & Integer'Image(Counters(I)));
end if;
end loop;
end Letter_Frequency;</lang>
- Output:
(counting the characters of its own source code)
>./letter_frequency ' ': 122 '"': 6 '&': 3 ... [a lot of lines omitted] 'x': 7 'y': 5 'z': 1
Aikido
<lang aikido>import ctype
var letters = new int [26]
var s = openin (args[0]) while (!s.eof()) {
var ch = s.getchar()
if (s.eof()) {
break
}
if (ctype.isalpha (ch)) {
var n = cast<int>(ctype.tolower(ch) - 'a')
++letters[n]
}
}
foreach i letters.size() {
println (cast<char>('a' + i) + " " + letters[i])
}</lang>
ALGOL 68
<lang algol68> BEGIN
[0:max abs char]INT histogram;
FOR i FROM 0 TO max abs char DO histogram[i] := 0 OD;
FILE input file;
STRING input file name = "Letter_frequency.a68";
IF open (input file, input file name, stand in channel) /= 0 THEN
put (stand error, ("Cannot open ", input file name, newline));
stop
ELSE
on file end (input file, (REF FILE f) BOOL: (close (f); GOTO finished))
FI;
DO
STRING s;
get (input file, (s, newline));
FOR i TO UPB s DO
CHAR c = s[i]; IF "A" <= c AND c <= "Z" OR "a" <= c AND c <= "z" THEN histogram[ABS c] PLUSAB 1 FI
OD OD; close (input file);
finished:
FOR i FROM ABS "A" TO ABS "Z" DO printf (($a3xg(0)l$, REPR i, histogram[i])) OD; FOR i FROM ABS "a" TO ABS "z" DO printf (($a3xg(0)l$, REPR i, histogram[i])) OD
END </lang>
- Output:
Counting letters in its own source code
A 11 B 9 C 2 D 13 E 11 F 14 G 4 H 3 I 10 J 0 [[ Omitted for K – Z and a – p ]] q 1 r 15 s 19 t 24 u 10 v 0 w 3 x 4 y 1 z 2
APL
<lang apl>
freq←{(⍪∪⍵),+/(∪⍵)∘.⍷⍵}
freq 0 1 2 3 2 3 4 3 4 4 4
0 1 1 1 2 2 3 3 4 4
freq 'balloon'
b 1 a 1 l 2 o 2 n 1 </lang>
AutoHotkey
<lang AutoHotkey>OpenFile = %A_ScriptFullPath% ; use own source code FileRead, FileText, %OpenFile% Loop 26 { StringReplace, junk, FileText, % Chr(96+A_Index),, UseErrorLevel out .= Chr(96+A_Index) ": " ErrorLevel "`n" } MsgBox % out</lang>
- Output:
(using script's own file)
a: 6 b: 1 c: 6 d: 4 e: 24 [several lines omitted] x: 5 y: 0 z: 0
AutoIt
This function prints the Letter frequency of a given textfile. You can choose to use case sensitive search and if special chars should be searched too.
<lang> Func _Letter_frequency($Path, $fcase = True, $fspecial_chars = True) Local $hFile, $sRead, $iupto, $iStart, $iCount If Not $fcase Then $fcase = False If Not $fspecial_chars Then $iStart = 64 If Not $fcase Then $iupto = 26 Else $iupto = 58 EndIf Else $iStart = 31 $iupto = 224 EndIf $hFile = FileOpen($Path, 0) $sRead = FileRead($hFile) FileClose($hFile) For $i = 1 To $iupto If Not $fspecial_chars Then If $iStart + $i > 90 And $iStart + $i < 97 Then ContinueLoop EndIf $sRead = StringReplace($sRead, Chr($iStart + $i), "", 0, $fcase) $iCount = @extended If $iCount > 0 Then ConsoleWrite(Chr($iStart + $i) & " : " & $iCount & @CRLF) Next EndFunc ;==>_Letter_frequency</lang>
- Output:
A : 32 B : 2 C : 15 E : 31 F : 10 [several lines omitted] u : 14 v : 1 w : 1 x : 14
AWK
<lang AWK>
- usage: awk -f letters.awk HolyBible.txt
BEGIN { FS="" }
{ for(i=1;i<=NF;i++) m[$i]++}
END { for(i in m) printf("%9d %-14s\n", m[i],i) } </lang>
BaCon
<lang freebasic>txt$ = LOAD$("bible.txt")
FOR x = 97 TO 122
PRINT CHR$(x-32), " ", CHR$(x), " : ", COUNT(txt$, x-32), " - ", COUNT(txt$, x)
NEXT </lang>
- Output:
A a : 17915 - 257815 B b : 4714 - 44161 C c : 1698 - 53373 D d : 8782 - 149313 E e : 2710 - 409525 F f : 2386 - 81157 G g : 6206 - 49096 H h : 3208 - 279471 I i : 13302 - 180660 J j : 6374 - 2515 K k : 547 - 21745 L l : 9222 - 120716 M m : 3056 - 76884 N n : 1891 - 223166 O o : 8896 - 234290 P p : 1877 - 41377 Q q : 6 - 958 R r : 7568 - 162761 S s : 4906 - 185124 T t : 7763 - 309983 U u : 333 - 83140 V v : 107 - 30258 W w : 2408 - 63079 X x : 2 - 1476 Y y : 569 - 58007 Z z : 904 - 2068
BBC BASIC
<lang bbcbasic> DIM cnt%(255)
file% = OPENIN("C:\unixdict.txt")
IF file%=0 ERROR 100, "Could not open file"
REPEAT
A$ = GET$#file%
L% = LEN(A$)
IF L% THEN
FOR I% = 1 TO L%
cnt%(ASCMID$(A$,I%)) += 1
NEXT
ENDIF
UNTIL EOF#file%
CLOSE #file%
FOR c% = &41 TO &5A
PRINT CHR$(c%)CHR$(c%+32) ": " cnt%(c%)+cnt%(c%+32)
NEXT</lang>
- Output:
Aa: 16421 Bb: 4115 Cc: 8216 Dd: 5799 Ee: 20144 Ff: 2662 Gg: 4129 Hh: 5208 Ii: 13980 Jj: 430 Kk: 1925 Ll: 10061 Mm: 5828 Nn: 12097 Oo: 12738 Pp: 5516 Qq: 378 Rr: 13436 Ss: 10210 Tt: 12836 Uu: 6489 Vv: 1902 Ww: 1968 Xx: 617 Yy: 3633 Zz: 433
Bracmat
<lang bracmat>(lc=
counts c
. fil$(!arg,r) {open file for reading}
& 0:?counts
& whl
' ( fil$:?c {read a byte}
& ( !c:(~<A:~>Z|~<a:~>z)
| 0
)
+ !counts
: ?counts {simply add any found letter to the sum}
)
& fil$(,SET,-1) {close the file by seeking to impossible file position.}
| !counts {return the sum}
);
lc$"valid.bra" {example: count letters in Bracmat's validation suite.} </lang> <lang bracmat>107*A + 33*B + 37*C + 39*D + 74*E + 50*F + 27*G + 28*H + 20*I + 55*J + 32*K + 112*L + 36*M + 32*N + 621*O + 43*P + 25*R + 67*S + 62*T + 64*U + 5*V + 26*W + 353*X + 248*Y + 70*Z + 2173*a + 840*b + 738*c + 639*d + 1345*e + 472*f + 372*g + 568*h + 91*j + 142*k + 529*l + 409*m + 941*n + 840*o + 336*p + 65*q + 993*r + 1018*s + 2097*t + 978*u + 122*v + 156*w + 909*x + 685*y + 211*z + 1035*i</lang>
C
<lang c>/* declare array */ int frequency[26]; int ch; FILE* txt_file = fopen ("a_text_file.txt", "rt");
/* init the freq table: */ for (ch = 0; ch < 26; ch++)
frequency[ch] = 0;
while (1) {
ch = fgetc(txt_file); if (ch == EOF) break; /* end of file or read error. EOF is typically -1 */
/* assuming ASCII; "letters" means "a to z" */
if ('a' <= ch && ch <= 'z') /* lower case */
frequency[ch-'a']++;
else if ('A' <= ch && ch <= 'Z') /* upper case */
frequency[ch-'A']++;
}</lang>
C#
<lang csharp>using System; using System.Collections.Generic; using System.IO; using System.Linq;
class Program {
static SortedDictionary<TItem, int> GetFrequencies<TItem>(IEnumerable<TItem> items)
{
var dictionary = new SortedDictionary<TItem, int>();
foreach (var item in items)
{
if (dictionary.ContainsKey(item))
{
dictionary[item]++;
}
else
{
dictionary[item] = 1;
}
}
return dictionary;
}
static void Main(string[] arguments)
{
var file = arguments.FirstOrDefault();
if (File.Exists(file))
{
var text = File.ReadAllText(file);
foreach (var entry in GetFrequencies(text))
{
Console.WriteLine("{0}: {1}", entry.Key, entry.Value);
}
}
}
}</lang>
- Output:
: 1 !: 1 ,: 1 H: 1 d: 1 e: 1 l: 3 o: 2 r: 1 w: 1
Declarative approach:
<lang csharp> var freq = from c in str
where char.IsLetter(c)
orderby c
group c by c into g
select g.Key + ":" + g.Count();
foreach(var g in freq)
Console.WriteLine(g);
</lang>
C:2 I:1 K:1 L:2 W:1 a:4 ... y:2
C++
<lang cpp>#include <fstream>
- include <iostream>
int main() { std::ifstream input("filename.txt", std::ios_base::binary); if (!input) { std::cerr << "error: can't open file\n"; return -1; }
size_t count[256]; std::fill_n(count, 256, 0);
for (char c; input.get(c); ++count[uint8_t(c)]) // process input file ; // empty loop body
for (size_t i = 0; i < 256; ++i) { if (count[i] && isgraph(i)) // non-zero counts of printable characters { std::cout << char(i) << " = " << count[i] << '\n'; } } }</lang>
- Output:
when file contains "Hello, world!" (without quotes)
! = 1 , = 1 H = 1 d = 1 e = 1 l = 3 o = 2 r = 1 w = 1
Common Lisp
<lang lisp>(defun letter-freq (file)
(with-open-file (stream file) (let ((str (make-string (file-length stream)))
(arr (make-array 256 :element-type 'integer :initial-element 0)))
(read-sequence str stream)
(loop for c across str do (incf (aref arr (char-code c))))
(loop for c from 32 to 126 for i from 1 do
(format t "~c: ~d~a" (code-char c) (aref arr c) (if (zerop (rem i 8)) #\newline #\tab))))))
(letter-freq "test.lisp")</lang>
Clojure
<lang Clojure>(println (sort-by second > (frequencies (map #(java.lang.Character/toUpperCase %) (filter #(java.lang.Character/isLetter %) (slurp "text.txt"))))))</lang>
Component Pascal
BlackBox Component Builder <lang oberon2> MODULE LetterFrecuency; IMPORT Files,StdLog,Strings;
PROCEDURE Do*; VAR loc: Files.Locator; fd: Files.File; rd: Files.Reader; x: BYTE; frecuency: ARRAY 26 OF LONGINT; c: CHAR; i: INTEGER; BEGIN loc := Files.dir.This("BBTest/Mod"); fd := Files.dir.Old(loc,"LetterFrecuency.odc",FALSE); rd := fd.NewReader(NIL);
(* init the frecuency array *) FOR i := 0 TO LEN(frecuency) - 1 DO frecuency[i] := 0 END;
(* collect frecuencies *) WHILE ~rd.eof DO rd.ReadByte(x);c := CAP(CHR(x)); (* convert vowels with diacritics *) CASE ORD(c) OF 193: c := 'A'; |201: c := 'E'; |205: c := 'I'; |211: c := 'O'; |218: c := 'U'; ELSE END; IF (c >= 'A') & (c <= 'Z') THEN INC(frecuency[ORD(c) - ORD('A')]); END END;
(* show data *)
FOR i := 0 TO LEN(frecuency) - 1 DO
StdLog.Char(CHR(i + ORD('A')));StdLog.String(":> ");StdLog.Int(frecuency[i]);
StdLog.Ln
END
END Do;
END LetterFrecuency.
</lang>
Execute: ^Q LetterFrecuency.Do
- Output:
A:> 28 B:> 7 C:> 100 D:> 94 E:> 168 F:> 30 G:> 10 H:> 11 I:> 49 J:> 0 K:> 1 L:> 67 M:> 25 N:> 57 O:> 81 P:> 3 Q:> 0 R:> 91 S:> 90 T:> 94 U:> 32 V:> 14 W:> 15 X:> 15 Y:> 17 Z:> 3
D
<lang d>void main() {
import std.stdio, std.ascii, std.algorithm, std.range;
uint[26] frequency;
foreach (const buffer; "unixdict.txt".File.byChunk(2 ^^ 15))
foreach (immutable c; buffer.filter!isAlpha)
frequency[c.toLower - 'a']++;
writefln("%(%(%s, %),\n%)", frequency[].chunks(10));
}</lang>
- Output:
16421, 4115, 8216, 5799, 20144, 2662, 4129, 5208, 13980, 430, 1925, 10061, 5828, 12097, 12738, 5516, 378, 13436, 10210, 12836, 6489, 1902, 1968, 617, 3633, 433
EchoLisp
We use a property list - plist for short - which is a hash table, to store the pairs ( letter . count) . <lang lisp>
- bump count when letter added
(define (hash-counter hash key ) ;; (set! key (string-downcase key)) - if ignore case wanted (putprop hash (1+ (or (getprop hash key) 0 )) key))
- apply to exploded string
- and sort result
(define (hash-compare a b) ( < (first a) (first b))) (define (count-letters hash string) (map (curry hash-counter hash) (string->list string)) (list-sort hash-compare (symbol-plist hash))) </lang>
- Output:
<lang lisp> (define (file-stats file string) (set-plist! 'file-stats null) ; reset counters (writeln (count-letters 'file-stats string)) (writeln "Total letters:" (string-length string)) (writeln "Total lines:" (getprop 'file-stats "#\\newline")))
- frequency for 'help.html' file
(file->string file-stats) ; browser 'open' dialog
➛ help.html -> string ➛ (( 28918) (! 138) (# 1035) (#\newline 4539) (#\tab 409) ($ 7) (% 24) (& 136) (' 1643) ((3577) () 3583) (* 233)
(+ 303) (, 599) (- 3164) (. 1454) (/ 5388) (0 1567) (1 1769) (2 1258) (3 857) (4 1872) (5 453) (6 581) (7 344)
(8 337) (9 411) (: 1235) (; 647) (< 9951) (= 1834) (> 10255) (? 392) (@ 11) (A 166) (B 92) (C 144) (D 72) (E 224)
(F 52) (G 35) (H 42) (I 193) (J 31) (K 36) (L 196) (M 82) (N 94) (O 132) (P 192) (Q 27) (R 56) (S 220) (T 226) (U 37)
(V 51) (W 28) (X 6) (Y 38) (Z 2) ([ 237) (\ 12) (] 215) (^ 28) (_ 107) (` 7) (a 8420) (b 4437) (c 3879) (d 4201)
(e 11905) (f 2989) (g 2068) (h 3856) (i 11313) (j 334) (k 653) (l 5748) (m 3048) (n 7020) (o 7207) (p 3585) (q 249)
(r 8312) (s 8284) (t 8704) (u 3833) (v 1135) (w 861) (x 1172) (y 1451) (z 268) ({ 123) (| 62) (} 123) (~ 7) (§ 1) (© 1)
(« 1) (» 1) (É 2) (à 18) (â 3) (ç 3) (è 6) (é 53) (î 1) (ö 9) (û 1) (œ 1) (ε 2) (λ 12) (μ 1) (ο 2) (ς 1)
(τ 1) (а 1) (д 1) (е 1) (з 1) (л 1) (м 1) (н 1) (я 3) (ἄ 1) (— 2) (“ 2) (” 2) (… 184) (→ 465) (∅ 57) (∈ 4) (∏ 1)
(∑ 2) (∘ 6) (√ 4)(∞ 12) (∫ 2) (⌚ 2) (⌛ 1) (⏳ 4) (☕ 1) (♠ 7) (♡ 2) (♢ 2) (♣ 6) (♤ 2) (♥ 8) (♦ 8)
(♧ 2) (⚁ 1) (⚃ 2) (⚪ 1) (⛔ 1) (✋ 1) (❄ 1) (❅ 1) (❆ 1) (❇ 1) (❈ 1) (❉ 1) (❊ 1) (❋ 1) (❌ 3) (❍ 1)
(❎ 1) (❗ 1) (➛ 900) (➰ 1) (⭕ 2) ... )
➛ Total letters: 212631 ➛ Total lines: 4539 </lang>
Eiffel
<lang Eiffel>class APPLICATION
create make
feature {NONE} -- Initialization
make -- Read from the file and print frequencies. local file: PLAIN_TEXT_FILE do create file.make_open_read("input.txt") file.read_stream(file.count) file.close across get_frequencies(file.last_string) as f loop print(f.key.out + ": " + f.item.out + "%N") end end
feature -- Access
get_frequencies (s: STRING): HASH_TABLE[INTEGER, CHARACTER] -- Hash table of counts for alphabetic characters in `s'. local char: CHARACTER do create Result.make(0) across s.area as st loop char := st.item if char.is_alpha then if Result.has(char) then Result.force(Result.at(char) + 1, char) else Result.put (1, char) end end end end end</lang>
- Output:
when file contains "Hello, Eiffel world!"
H: 1 e: 2 l: 4 o: 2 E: 1 i: 1 f: 2 w: 1 r: 1 d: 1
Elixir
<lang elixir>file = hd(System.argv)
File.read!(file) |> String.upcase |> String.graphemes |> Enum.filter(fn c -> c =~ ~r/[A-Z]/ end) |> Enum.reduce(Map.new, fn c,acc -> Map.update(acc, c, 1, &(&1+1)) end) |> Enum.sort_by(fn {_k,v} -> -v end) |> Enum.each(fn {k,v} -> IO.puts "#{k} #{v}" end)</lang>
- Output:
C:\Elixir>elixir letterfrequency.exs \work\unixdict.txt E 20144 A 16421 I 13980 R 13436 T 12836 O 12738 N 12097 S 10210 L 10061 C 8216 U 6489 M 5828 D 5799 P 5516 H 5208 G 4129 B 4115 Y 3633 F 2662 W 1968 K 1925 V 1902 X 617 Z 433 J 430 Q 378
Erlang
<lang erlang>%% Implemented by Arjun Sunel -module(letter_frequency). -export([main/0, letter_freq/1]). main() -> case file:read_file("file.txt") of {ok, FileData} -> letter_freq(binary_to_list(FileData)); _FileNotExist -> io:format("File do not exist~n") end.
letter_freq(Data) -> lists:foreach(fun(Char) -> LetterCount = lists:foldl(fun(Element, Count) -> case Element =:= Char of true -> Count+1; false -> Count end end, 0, Data),
case LetterCount >0 of true -> io:format("~p : ~p~n", [[Char], LetterCount]); false -> io:format("") end end, lists:seq(0, 222)). </lang>
- Output:
"\n" : 5 " " : 4 "," : 1 "." : 22 ":" : 3 "M" : 1 "a" : 2 "e" : 2 "i" : 1 "j" : 1 "l" : 1 "m" : 1 "n" : 3 "r" : 1 "s" : 2 "u" : 2 "y" : 1 "}" : 2 ok
Alternatively letter_freq/1 above can be replaced with <lang Erlang> letter_freq( Data ) -> Dict = lists:foldl( fun (Char, Dict) -> dict:update_counter( Char, 1, Dict ) end, dict:new(), Data ), [io:fwrite( "~p : ~p~n", [[X], dict:fetch(X, Dict)]) || X <- dict:fetch_keys(Dict)]. </lang>
ERRE
Using ERRE help file for testing. <lang ERRE>PROGRAM LETTER
DIM CNT[255]
BEGIN
OPEN("I",1,"f:\errev30\erre.hlp")
REPEAT
GET(#1,A$)
L%=LEN(A$)
IF L%>0 THEN
FOR I%=1 TO L% DO
A%=ASC(MID$(A$,I%))
CNT[A%]+=1
END FOR
END IF
UNTIL EOF(1)
CLOSE(1)
FOR C%=$41 TO $5A DO
PRINT(CHR$(C%);CHR$(C%+32);": ";CNT[C%]+CNT[C%+32])
END FOR
END PROGRAM </lang>
Euphoria
<lang euphoria> -- LetterFrequency.ex -- Count frequency of each letter in own source code.
include std/console.e include std/io.e include std/text.e
sequence letters = repeat(0,26)
sequence content = read_file("LetterFrequency.ex")
content = lower(content)
for i = 1 to length(content) do if content[i] > 96 and content[i] < 123 then letters[content[i]-96] += 1 end if end for
for i = 1 to 26 do printf(1,"%s: %d\n",{i+96,letters[i]}) end for
if getc(0) then end if </lang>
- Output:
a: 4 b: 0 c: 21 -snip x: 3 y: 3 z: 0
F#
<lang fsharp>let alphabet =
['A'..'Z'] |> Set.ofList
let letterFreq (text : string) =
text.ToUpper().ToCharArray() |> Array.filter (fun x -> alphabet.Contains(x)) |> Seq.countBy (fun x -> x) |> Seq.sort
let v = "Now is the time for all good men to come to the aid of the party"
let res = letterFreq v
for (letter, freq) in res do
printfn "%A, %A" letter freq</lang>
FBSL
The result of the first evaluation of ASC() is retained in the symbol ASC for later use. This is a standard feature of FBSL functions. The ascii array is dynamic. Command(1) is the name of the script file.
<lang qbasic>#APPTYPE CONSOLE
'Open a text file and count the occurrences of each letter. FUNCTION countBytes(fileName AS STRING) DIM c AS STRING DIM ascii[] DIM handle AS INTEGER = FILEOPEN(fileName, BINARY) WHILE NOT FILEEOF(handle) c = FILEGETC(handle) IF c = "" THEN EXIT WHILE ascii[ASC] = ascii[ASC(c)] + 1 WEND FILECLOSE(handle) RETURN ascii END SUB
DIM counters = countBytes(COMMAND(1)) FOR DIM i = LBOUND(counters) TO UBOUND(counters) PRINT i, TAB, IIF(i <= 32, i, CHR(i)), TAB, counters[i] NEXT
PAUSE </lang>
Factor
<lang factor>USING: hashtables locals io assocs kernel io.encodings.utf8 io.files formatting ; IN: count-letters
<PRIVATE
- count-from-stream ( -- counts )
52 <hashtable> [ read1 dup ] [ over inc-at ] while drop ;
- print-counts ( counts -- )
[ "%c: %d\n" printf ] assoc-each ;
PRIVATE>
- count-letters ( filename -- )
utf8 [ count-from-stream ] with-file-reader print-counts ;
</lang>
Forth
<lang forth>create counts 26 cells allot
- freq ( filename -- )
counts 26 cells erase
slurp-file bounds do
i c@ 32 or 'a -
dup 0 26 within if
cells counts +
1 swap +!
else drop then
loop
26 0 do
cr [char] ' emit 'a i + emit ." ': "
counts i cells + @ .
loop ;
s" example.txt" freq</lang>
Fortran
Using the configuration file (which has changed since the example was documented) of the J example, compilation and output of this program on a gnu/linux system is <lang fortran> -*- mode: compilation; default-directory: "/tmp/" -*- Compilation started at Sat May 18 18:09:46
a=./F && make $a && $a < configuration.file f95 -Wall -ffree-form F.F -o F
92 21 17 24 82 19 19 22 67 0 2 27 27 57 55 31 1 61 43 60 20 6 2 0 10 0
Compilation finished at Sat May 18 18:09:46 </lang> And here's the FORTRAN90 program source. The program reads stdin and writes the result to stdout. Future enhancement: use block size records. <lang FORTRAN> ! count letters from stdin program LetterFrequency
implicit none
character (len=1) :: s
integer, dimension(26) :: a
integer :: ios, i, t
data a/26*0/,i/0/
open(unit=7, file='/dev/stdin', access='direct', form='formatted', recl=1, status='old', iostat=ios)
if (ios .ne. 0) then
write(0,*)'Opening stdin failed'
stop
endif
do i=1, huge(i)
read(unit=7, rec = i, fmt = '(a)', iostat = ios ) s
if (ios .ne. 0) then
!write(0,*)'ios on failure is ',ios
close(unit=7)
exit
endif
t = ior(iachar(s(1:1)), 32) - iachar('a')
if ((0 .le. t) .and. (t .le. iachar('z'))) then
t = t+1
a(t) = a(t) + 1
endif
end do
write(6, *) a
end program LetterFrequency </lang>
FreeBASIC
<lang freebasic>' FB 1.05.0 Win64
Dim a(65 to 90) As Integer ' array to hold frequency of each letter, all elements zero initially Dim fileName As String = "input.txt" Dim s As String Dim i As Integer Open fileName For Input As #1
While Not Eof(1)
Line Input #1, s s = UCase(s) For i = 0 To Len(s) - 1 a(s[i]) += 1 Next
Wend
Close #1
Print "The frequency of each letter in the file "; fileName; " is as follows:" Print For i = 65 To 90
If a(i) > 0 Then Print Chr(i); " : "; a(i) End If
Next Print Print "Press any key to quit" Sleep</lang>
- Output:
/' results for input.txt which contains the single line: The quick brown fox jumps over the lazy dog. '/ The frequency of each letter in the file input.txt is as follows: A : 1 B : 1 C : 1 D : 1 E : 3 F : 1 G : 1 H : 2 I : 1 J : 1 K : 1 L : 1 M : 1 N : 1 O : 4 P : 1 Q : 1 R : 2 S : 1 T : 2 U : 2 V : 1 W : 1 X : 1 Y : 1 Z : 1
Input:
This is the one question that most people ask. Why bother learning a completely different computing environment, when the operating system that ships with most desktops, laptops, and servers works just fine? To answer that question, I would pose another question. Does that operating system you’re currently using really work “just fine”? Or are you constantly battling viruses, malware, slow downs, crashes, costly repairs, and licensing fees? If you struggle with the above, and want to free yourself from the constant fear of losing data or having to take your computer in for the “yearly clean up,” Linux might be the perfect platform for you. Linux has evolved into one of the most reliable computer ecosystems on the planet. Combine that reliability with zero cost of entry and you have the perfect solution for a desktop platform.
Gambas
<lang gambas>Public Sub Form_Open() Dim sData As String = File.Load("data.txt") Dim iCount, iSpaces, iLetters, iOther As Integer Dim bPunctuation As Boolean
For iCount = 1 To Len(sData)
If InStr("ABCDEFGHIJKLMNOPQRSTUVWXYZ", UCase(Mid(sData, iCount, 1))) Then
Inc iLetters
bPunctuation = True
End If
If Mid(sData, icount, 1) = " " Then
Inc iSpaces
bPunctuation = True
End If
If bPunctuation = False Then Inc iOther
bPunctuation = False
Next
Message("Text contains " & Len(sData) & " characters\n" & iLetters & " Letters\n" & iSpaces & " Spaces\n" & iOther & " Punctuation, newlines etc.")
End</lang> Output:
Text contains 854 characters 677 Letters 135 Spaces 42 Punctuation, newlines etc.
Go
<lang go>package main
import (
"fmt" "io/ioutil" "sort" "unicode"
)
const file = "unixdict.txt"
func main() {
bs, err := ioutil.ReadFile(file)
if err != nil {
fmt.Println(err)
return
}
m := make(map[rune]int)
for _, r := range string(bs) {
m[r]++
}
// answer is now in m. sort and format output:
lfs := make(lfList, 0, len(m))
for l, f := range m {
lfs = append(lfs, &letterFreq{l, f})
}
sort.Sort(lfs)
fmt.Println("file:", file)
fmt.Println("letter frequency")
for _, lf := range lfs {
if unicode.IsGraphic(lf.rune) {
fmt.Printf(" %c %7d\n", lf.rune, lf.freq)
} else {
fmt.Printf("%U %7d\n", lf.rune, lf.freq)
}
}
}
type letterFreq struct {
rune freq int
} type lfList []*letterFreq
func (lfs lfList) Len() int { return len(lfs) } func (lfs lfList) Less(i, j int) bool {
switch fd := lfs[i].freq - lfs[j].freq; {
case fd < 0:
return false
case fd > 0:
return true
}
return lfs[i].rune < lfs[j].rune
} func (lfs lfList) Swap(i, j int) {
lfs[i], lfs[j] = lfs[j], lfs[i]
}</lang>
- Output:
file: unixdict.txt letter frequency U+000A 25104 e 20144 a 16421 i 13980 r 13436 t 12836 o 12738 n 12097 s 10210 l 10061 c 8216 u 6489 m 5828 d 5799 p 5516 h 5208 g 4129 b 4115 y 3633 f 2662 w 1968 k 1925 v 1902 x 617 z 433 j 430 q 378 ' 105 & 6 . 6 1 2 0 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 1
Groovy
<lang groovy>def frequency = { it.inject([:]) { map, value -> map[value] = (map[value] ?: 0) + 1; map } }
frequency(new File('frequency.groovy').text).each { key, value ->
println "'$key': $value"
}</lang>
- Output:
'd': 1 'e': 19 'f': 4 ' ': 29 'r': 5 'q': 3 'u': 8 [lines omitted] 'o': 2 'x': 1 'h': 1 'k': 2 '"': 2 '$': 2
Harbour
<lang visualfoxpro>PROCEDURE Main()
LOCAL s := hb_MemoRead( Left( __FILE__ , At( ".", __FILE__ )) +"prg")
LOCAL c, n, i
LOCAL a := {}
FOR EACH c IN s
IF Asc( c ) > 31
AAdd( a, c )
ENDIF
NEXT
a := ASort( a )
i := 1
WHILE i <= Len( a )
c := a[i] ; n := 1
i++
IF i < Len(a) .AND. c == a[i]
WHILE c == a[i]
n++ ; i++
END
ENDIF
?? "'" + c + "'" + "=" + hb_NtoS( n ) + " "
END
RETURN</lang>
- Output:
(counting the printable characters of its own source code)
' '=190 '"'=12 ' ' '=2 '('=10 ')'=10 '+'=12 ','=5 '.'=3 '1'=3 '3'=1 ':'=6 ';'=2 '<'=2 '='=12
'>'=1 '?'=2 'A'=10 'C'=5 'D'=6 'E'=13 'F'=7 'H'=3 'I'=9 'L'=13 'M'=2 'N'=9 'O'=5 'P'=1
'R'=6 'S'=2 'T'=2 'U'=2 'W'=2 'X'=1 '['=3 ']'=3 '_'=10 'a'=12 'b'=2 'c'=9 'd'=3 'e'=5
'f'=1 'g'=1 'h'=2 'i'=11 'm'=1 'n'=7 'o'=3 'p'=1 'r'=2 's'=3 't'=5 'w'=1 '{'=1 '}'=1
Haskell
Short version: <lang Haskell>import Data.List (group,sort) import Control.Arrow ((&&&)) main = interact (show . map (head &&& length) . group . sort)</lang>
Icon and Unicon
The example below counts (case insensitive) letters and was run on a version of this source file. <lang Icon>link printf
procedure main(A) every PrintCount(CountLetters(!A)) end
procedure CountLetters(fn) #: Return case insensitive count of letters
K := table(0)
if f := open(fn,"r") then {
every c := !map(|read(f)) do
if any(&lcase,c) then K[c] +:= 1
close(f)
return K
}
else write(&errout,"Unable to open file ",fn)
end
procedure PrintCount(T) #: Print the letters every c := key(T) do
printf("%s - %d\n",c,T[c])
end</lang>
printf.icn provides formatting
- Output:
c - 17 k - 5 s - 10 h - 2 p - 10 e - 41 m - 2 u - 12 b - 2 r - 25 o - 16 w - 1 d - 10 l - 10 t - 27 a - 10 i - 13 y - 5 f - 12 n - 28 v - 4
J
Input is a directory-path with filename. Result is 26 integers representing counts of each letter, in alphabetic order (a's count is first).
<lang j>ltrfreq=: 3 : 0
letters=. u: 65 + i.26 NB. upper case letters <: #/.~ letters (, -. -.~) toupper fread y
)</lang>
Example use (based on a configuration file from another task):
<lang j> ltrfreq 'config.file' 88 17 17 24 79 18 19 19 66 0 2 26 26 57 54 31 1 53 43 59 19 6 2 0 8 0</lang>
Java
<lang java5>import java.io.BufferedReader; import java.io.FileReader; import java.io.IOException; import java.util.Arrays;
public class LetterFreq { public static int[] countLetters(String filename) throws IOException{ int[] freqs = new int[26]; BufferedReader in = new BufferedReader(new FileReader(filename)); String line; while((line = in.readLine()) != null){ line = line.toUpperCase(); for(char ch:line.toCharArray()){ if(Character.isLetter(ch)){ freqs[ch - 'A']++; } } } in.close(); return freqs; }
public static void main(String[] args) throws IOException{ System.out.println(Arrays.toString(countLetters("filename.txt"))); } }</lang>
In Java 7, we can use try with resources. The countLetters method would look like this:
<lang java5>public static int[] countLetters(String filename) throws IOException{
int[] freqs = new int[26];
try(BufferedReader in = new BufferedReader(new FileReader(filename))){
String line;
while((line = in.readLine()) != null){
line = line.toUpperCase();
for(char ch:line.toCharArray()){
if(Character.isLetter(ch)){
freqs[ch - 'A']++;
}
}
}
}
return freqs;
}</lang>
In Java 8, we can use streams. This code also handles unicode codepoints as well. The countLetters method would look like this:
<lang java5>public static Map<Integer, Long> countLetters(String filename) throws IOException {
return Files.lines(Paths.get(filename))
.flatMapToInt(String::chars)
.filter(Character::isLetter)
.boxed()
.collect(Collectors.groupingBy(Function.identity(), Collectors.counting()));
}</lang>
JavaScript
JavaScript is no longer used only in environments which are carefully isolated from file systems, but JavaScript standards still do not specify standard file-system functions. Leaving aside the particular and variable details of how files will be opened and read in environments like Node.js and OS X JavaScript for Automation etc., we can still use core JavasScript (ES5 in the example below), to count the characters in a text once it has been read from a file system.
<lang JavaScript>(function(txt) {
var cs = txt.split(),
i = cs.length,
dct = {},
c = ,
keys;
while (i--) {
c = cs[i];
dct[c] = (dct[c] || 0) + 1;
}
keys = Object.keys(dct);
keys.sort();
return keys.map(function (c) { return [c, dct[c]]; });
})("Not all that Mrs. Bennet, however, with the assistance of her five\ daughters, could ask on the subject, was sufficient to draw from her\ husband any satisfactory description of Mr. Bingley. They attacked him\ in various ways--with barefaced questions, ingenious suppositions, and\ distant surmises; but he eluded the skill of them all, and they were at\ last obliged to accept the second-hand intelligence of their neighbour,\ Lady Lucas. Her report was highly favourable. Sir William had been\ delighted with him. He was quite young, wonderfully handsome, extremely\ agreeable, and, to crown the whole, he meant to be at the next assembly\ with a large party. Nothing could be more delightful! To be fond of\ dancing was a certain step towards falling in love; and very lively\ hopes of Mr. Bingley's heart were entertained."); </lang>
- Output:
<lang JavaScript>[[" ", 121], ["!", 1], ["'", 1], [",", 13], ["-", 3], [".", 9], [";", 2], ["B", 3], ["H", 2], ["L", 2], ["M", 3], ["N", 2], ["S", 1], ["T", 2], ["W", 1], ["a", 53], ["b", 13], ["c", 17], ["d", 29], ["e", 82], ["f", 17], ["g", 16], ["h", 36], ["i", 44], ["j", 1], ["k", 3], ["l", 34], ["m", 11], ["n", 41], ["o", 40], ["p", 8], ["q", 2], ["r", 35], ["s", 39], ["t", 55], ["u", 20], ["v", 7], ["w", 17], ["x", 2], ["y", 16]]</lang>
jq
The following program will report the frequency of all characters in the input file, including newlines, returns, etc, provided the file will fit in memory.<lang jq>
- Input: an array of strings.
- Output: an object with the strings as keys,
- the values of which are the corresponding frequencies.
def counter:
reduce .[] as $item ( {}; .[$item] += 1 ) ;
- For neatness we sort the keys:
explode | map( [.] | implode ) | counter | . as $counter
| keys | sort[] | [., $counter[.] ]
</lang> Example:<lang sh>jq -s -R -c -f Letter_frequency.jq somefile.txt</lang>
- Output:
["\n",12]
[" ",124]
["#",1]
["$",8]
["(",4]
[")",4]
["+",3]
[",",4]
["-",4]
[".",9]
["0",3]
["1",7]
[":",2]
[";",2]
["=",4]
...
Julia
This will return the frequency of all characters in file, including newlines. Filter the result according to the desired set of letters. <lang Julia>function freq(file)
h = Dict{Char, Integer}()
for x in open(readstring ,file) h[x] = get(h,x,0)+1 end
sort(collect(h))
end</lang>
- Output:
julia> filter(l-> l[1] in ['a':'z','A':'Z'], freq("somefile.txt"))
52-element Array{(Char,Integer),1}:
('A',478)
('B',453)
...
K
<lang K>+(?a;#:'=a:,/0:`)</lang>
Example: The file "hello.txt" contains the string "Hello, world!"
<lang K>
c:+(?a;#:'=a:,/0:`hello.txt)
</lang>
- Output:
(("H";1)
("e";1)
("l";3)
("o";2)
(",";1)
(" ";1)
("w";1)
("r";1)
("d";1)
("!";1))
Sort on decreasing occurrences:
<lang K>
c@>c[;1]
</lang>
- Output:
(("l";3)
("o";2)
("H";1)
("e";1)
(",";1)
(" ";1)
("w";1)
("r";1)
("d";1)
("!";1))
Kotlin
<lang scala>// version 1.1.2
import java.io.File
fun main(args: Array<String>) {
val text = File("input.txt").readText().toLowerCase()
val letterMap = text.filter { it in 'a'..'z' }.groupBy { it }.toSortedMap()
for (letter in letterMap) println("${letter.key} = ${letter.value.size}")
val sum = letterMap.values.sumBy { it.size }
println("\nTotal letters = $sum")
}</lang>
- Output:
'input.txt' just contains two pangrams:
The quick brown fox jumps over the lazy dog. Sphinx of black quartz, judge my vow.
a = 3 b = 2 c = 2 d = 2 e = 4 f = 2 g = 2 h = 3 i = 2 j = 2 k = 2 l = 2 m = 2 n = 2 o = 6 p = 2 q = 2 r = 3 s = 2 t = 3 u = 4 v = 2 w = 2 x = 2 y = 2 z = 2 Total letters = 64
Liberty BASIC
Un-rem a line to convert to all-upper-case. Letter freq'y is printed as percentages. <lang lb>
open "text.txt" for input as #i
txt$ =input$( #i, lof( #i))
Le =len( txt$)
close #i
dim LetterFreqy( 255)
' txt$ =upper$( txt$)
for i =1 to Le
char =asc( mid$( txt$, i, 1))
if char >=32 then LetterFreqy( char) =LetterFreqy( char) +1
next i
for j =32 to 255
if LetterFreqy( j) <>0 then print " Character #"; j, "("; chr$( j);_
") appeared "; using( "##.##", 100 *LetterFreqy( j) /Le); "% of the time."
next j
end
</lang>
Lasso
<lang Lasso>local( str = 'Hello world!', freq = map ) // as a loop. arguably quicker than query expression loop(#str->size) => { #freq->keys !>> #str->get(loop_count) ? #freq->insert(#str->get(loop_count) = #str->values->find(#str->get(loop_count))->size) }
// or local( str = 'Hello world!', freq = map ) // as query expression, less code with i in #str->values where #freq->keys !>> #i do => { #freq->insert(#i = #str->values->find(#i)->size) }
// output #freq with elem in #freq->keys do => {^ '"'+#elem+'": '+#freq->find(#elem)+'\r' ^}</lang>
Lua
This solution counts letters only, which could be changed by altering the pattern argument to 'gmatch' on line 31. It also treats upper and lower case letters as distinct, which could be changed by changing everything to upper or lower case with string.upper() or string.lower() before tallying. <lang lua>-- Return entire contents of named file function readFile (filename)
local file = assert(io.open(filename, "r"))
local contents = file:read("*all")
file:close()
return contents
end
-- Return a closure to keep track of letter counts function tally ()
local t = {}
-- Add x to tally if supplied, return tally list otherwise
local function count (x)
if x then
if t[x] then
t[x] = t[x] + 1
else
t[x] = 1
end
else
return t
end
end
return count
end
-- Main procedure local letterCount = tally() for letter in readFile(arg[1]):gmatch("%a") do
letterCount(letter)
end for k, v in pairs(letterCount()) do
print(k, v)
end</lang> Output from running this script on itself:
i 24 g 2 h 4 e 61 f 16 c 19 d 17 R 2 o 31 p 7 m 4 n 42 k 4 l 40 y 4 w 1 x 7 u 18 v 2 s 14 t 54 a 24 C 3 M 1 A 1 F 2 r 32
Maple
<lang Maple>StringTools:-CharacterFrequencies(readbytes("File.txt",infinity,TEXT))</lang>
Mathematica / Wolfram Language
<lang Mathematica>Tally[Characters[Import["file.txt","Text"]]]</lang>
MATLAB / Octave
<lang MATLAB>function u = letter_frequency(t) if ischar(t) t = abs(t); end; A = sparse(t+1,1,1,256,1); printf('"%c":%i\n',[find(A)-1,A(A>0)]') end</lang>
NetRexx
<lang netrexx>/* NetRexx ************************************************************
- 22.05.2013 Walter Pachl translated from REXX
- /
options replace format comments java crossref symbols nobinary
parse arg dsn . if dsn = then dsn = 'test.txt' cnt=0 totChars=0 /*count of the total num of chars*/ totLetters=0 /*count of the total num letters.*/ indent=' '.left(20) /*used for indentation of output.*/ lines = scanFile(dsn) loop l_ = 1 to lines[0] line = lines[l_]
Say '>'line'<' line.length /* that's in test.txt */
/*
lrx=left_right(line)
Parse lrx leftx rightx
Say ' 'leftx
Say ' 'rightx
*/
loop k=1 for line.length() /*loop over characters */
totChars=totChars+1 /*Increment total number of chars*/
c=line.substr(k,1) /*get character number k */
cnt[c]=cnt[c]+1 /*increment the character's count*/
End
end l_
w=totChars.length /*used for right-aligning counts.*/
say 'file -----' dsn "----- has" lines[0] 'records.'
say 'file -----' dsn "----- has" totChars 'characters.'
Loop L=0 to 255 /* display nonzero letter counts */
c=l.d2c /* the character in question */
if cnt[c]>0 & c.datatype('M')>0 Then Do /* was found in the file */
/* and is a latin letter */
say indent "(Latin) letter " c 'count:' cnt[c].right(w) /* tell */
totLetters=totLetters+cnt[c] /* increment number of letters */
End
End
say 'file -----' dsn "----- has" totLetters '(Latin) letters.'
say ' other charactes follow'
other=0
loop m=0 to 255 /* now for non-letters */
c=m.d2c /* the character in question */
y=c.c2x /* the hex representation */
if cnt[c]>0 & c.datatype('M')=0 Then Do /* was found in the file */
/* and is not a latin letter */
other=other+cnt[c] /* increment count */
_=cnt[c].right(w) /* prepare output of count */
select /*make the character viewable. */
when c<<' ' | m==255 then say indent "'"y"'x character count:" _
when c==' ' then say indent "blank character count:" _
otherwise say indent " " c 'character count:' _
end
end
end
say 'file -----' dsn "----- has" other 'other characters.'
say 'file -----' dsn "----- has" totLetters 'letters.'
-- Read a file and return contents as a Rexx indexed string method scanFile(dsn) public static returns Rexx
fileLines =
do
inFile = File(dsn)
inFileScanner = Scanner(inFile)
loop l_ = 1 while inFileScanner.hasNext()
fileLines[0] = l_
fileLines[l_] = inFileScanner.nextLine()
end l_
inFileScanner.close()
catch ex = FileNotFoundException ex.printStackTrace end
return fileLines</lang>
Nim
<lang nim>import tables, os
var t = initCountTable[char]() var f = open(paramStr(1)) for l in f.lines:
for c in l: t.inc(c)
echo t</lang>
Objeck
<lang objeck> use IO;
bundle Default {
class Test {
function : Main(args : String[]) ~ Nil {
freqs := CountLetters("filename.txt");
for(i := 'A'; i < 'Z'; i += 1;) {
Console->Print(i->As(Char))->Print("=>")->PrintLine(freqs[i - 'A']);
};
}
function : CountLetters(filename : String) ~ Int[] {
freqs := Int->New[26];
reader := FileReader->New(filename);
while(reader->IsEOF() <> true) {
line := reader->ReadString()->ToUpper();
each(i : line) {
ch := line->Get(i);
if(ch->IsChar()){
index := ch - 'A';
freqs[index] := freqs[index] + 1;
};
};
};
reader->Close();
return freqs;
}
}
} </lang>
Objective-C
<lang objc>#import <Foundation/Foundation.h>
int main (int argc, const char *argv[]) {
@autoreleasepool {
NSData *data = [NSData dataWithContentsOfFile:@(argv[1])];
NSString *string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSCountedSet *countedSet = [[NSCountedSet alloc] init];
NSUInteger len = [string length];
for (NSUInteger i = 0; i < len; i++) {
unichar c = [string characterAtIndex:i];
if ([[NSCharacterSet letterCharacterSet] characterIsMember:c])
[countedSet addObject:@(c)];
}
for (NSNumber *chr in countedSet) {
NSLog(@"%C => %lu", (unichar)[chr integerValue], [countedSet countForObject:chr]);
}
}
return 0;
}</lang>
OCaml
We open a text file and compute letter frequency. Other characters than [a-z] and [A-Z] are ignored, and upper case letters are first converted to lower case before to compute letter frequency.
<lang ocaml>let () =
let ic = open_in Sys.argv.(1) in
let base = int_of_char 'a' in
let arr = Array.make 26 0 in
try while true do
let c = Char.lowercase(input_char ic) in
let ndx = int_of_char c - base in
if ndx < 26 && ndx >= 0 then
arr.(ndx) <- succ arr.(ndx)
done
with End_of_file ->
close_in ic;
for i=0 to 25 do
Printf.printf "%c -> %d\n" (char_of_int(i + base)) arr.(i)
done</lang>
If we want to compute all characters in an UTF8 file, we must use an external library, for example Batteries. The following function takes as input a string that contains the path to the file, and prints all the characters together with their frequencies, ordered by increasing frequencies, on the standard output.
<lang ocaml> open Batteries
let frequency file =
let freq = Hashtbl.create 52 in
File.with_file_in file
(Enum.iter (fun c -> Hashtbl.modify_def 1 c succ freq) % Text.chars_of);
List.iter (fun (k,v) -> Text.write_text stdout k;
Printf.printf " %d\n" v)
@@ List.sort (fun (_,v) (_,v') -> compare v v')
@@ Hashtbl.fold (fun k v l -> (Text.of_uchar k,v) :: l) freq []
</lang>
OxygenBasic
<lang oxygenbasic> indexbase 0
sys a,e,i,c[255]
string s=getfile "t.txt"
e=len s
for i=1 to e
a=asc(s,i) ++c(a)
next
cr=chr(13)+chr(10) pr="Char Frequencies" cr cr for i=32 to 255
pr+=chr(i) chr(9) c(i) cr
next
print pr 'putfile "CharCount.txt",pr </lang>
PARI/GP
<lang parigp>v=vector(26); U=readvec("foo.txt"); for(i=1,#U,u=Vecsmall(U[i]);for(j=1,#u,if(u[j]>64&&u[j]<91,v[u[j]-64]++,u[j]>96&&u[j]<123,v[u[j]-96]++))); v</lang>
Pascal
<lang pascal>program LetterFrequency; var
textFile: text; character: char; counter: array[0..255] of integer; i: integer;
begin
for i := low(counter) to high(counter) do
counter[i] := 0;
assign(textFile, 'a_text_file.txt');
reset(textFile);
while not eof(textFile) do
begin
while not eoln(textFile) do
begin
read(textFile, character);
inc(counter[ord(character)]);
end;
readln(textFile);
end;
for i := low(counter) to high(counter) do
if counter[i] > 0 then
writeln(char(i), ': ', counter[i]);
end. </lang>
- Output:
>: ./LetterFrequency 3: 2 a: 4 d: 3 e: 3 f: 3 g: 2 q: 1 r: 4 s: 3 t: 2 w: 2
Perl
Counts letters in files given on command line or piped to stdin. Case insensitive. <lang perl>while (<>) { $cnt{lc chop}++ while length } print "$_: ", $cnt{$_}//0, "\n" for 'a' .. 'z';</lang>
Perl 6
In perl6, whenever you want to count things in a collection, the rule of thumb is to use the Bag structure. <lang perl6>say bag lines».comb</lang>
Phix
Counts own source or supplied filename <lang Phix>sequence lc = repeat(0,#7E) integer fn = open(command_line()[$],"rb"), ch while 1 do
ch = getc(fn)
if ch=-1 then exit end if
if ch>=' ' and ch<#7F then
lc[ch] += 1
end if
end while close(fn)
for i=' ' to #7E do
if lc[i]!=0 then
printf(1,"'%c': %d%s",{i,lc[i],iff(mod(i,32)=31?'\n':'\t')})
end if
end for {} = wait_key()</lang>
- Output:
' ': 77 '!': 1 '"': 4 '#': 3 '$': 1 '%': 3 ''': 10 '(': 9 ')': 9 '+': 1 ',': 8 '-': 1 '0': 2 '1': 5 '2': 1 '3': 2 '7': 3 ':': 2 '<': 1 '=': 10 '>': 1 '?': 1
'E': 2 'F': 1 '[': 4 '\': 2 ']': 4 '_': 2
'a': 4 'b': 1 'c': 15 'd': 11 'e': 23 'f': 14 'g': 2 'h': 11 'i': 19 'k': 1 'l': 8 'm': 3 'n': 19 'o': 9 'p': 3 'q': 1 'r': 6 's': 3 't': 11 'u': 1 'w': 3 'x': 1 'y': 1 '{': 2 '}': 2
PHP
<lang php><?php print_r(array_count_values(str_split(file_get_contents($argv[1])))); ?></lang>
PicoLisp
<lang PicoLisp>(let Freq NIL
(in "file.txt"
(while (char) (accu 'Freq @ 1)) )
(sort Freq) )</lang>
For a "file.txt":
abcd cdef
- Output:
-> (("^J" . 2) ("a" . 1) ("b" . 1) ("c" . 2) ("d" . 2) ("e" . 1) ("f" . 1))
PL/I
<lang PL/I> frequencies: procedure options (main);
declare tallies(26) fixed binary static initial ((26) 0);
declare alphabet character (26) static initial
('ABCDEFGHIJKLMNOPQRSTUVWXYZ');
declare c character (1), i fixed binary;
declare in file;
open file (in) title ('/LETTER.DAT,type(text),recsize(200)') input;
on endfile (in) go to prepare_list;
do while('1'b);
get file (in) edit (c) (a(1)); put edit (c) (a);
i = index(alphabet, c);
if i > 0 then tallies(i) = tallies(i) + 1;
end;
prepare_list:
put skip list('Letter', 'Frequency');
do i = 1 to 26;
if tallies(i) > 0 then
put skip list (substr(alphabet, i, 1), tallies(i));
end;
end frequencies;</lang> Data:
THEQUICKBROWNFOX JUMPSOVERTHELAZYDOG
- Output:
Letter Frequency A 1 B 1 C 1 D 1 E 3 F 1 G 1 H 2 I 1 J 1 K 1 L 1 M 1 N 1 O 4 P 1 Q 1 R 2 S 1 T 2 U 2 V 1 W 1 X 1 Y 1 Z 1
PowerShell
<lang PowerShell> function frequency ($string) {
$arr = $string.ToUpper().ToCharArray() |where{$_ -match '[A-KL-Z]'}
$n = $arr.count
$arr | group | foreach{
[pscustomobject]@{letter = "$($_.name)"; frequency = "$([math]::round($($_.Count/$n),5))"; count = "$($_.count)"}
} | sort letter
} $file = "$($MyInvocation.MyCommand.Name )" #Put the name of your file here frequency $(get-content $file -Raw) </lang> Output:
letter frequency count ------ --------- ----- A 0.06809 16 B 0.00426 1 C 0.06809 16 D 0.00851 2 E 0.11064 26 F 0.0383 9 G 0.01702 4 H 0.02979 7 I 0.03404 8 J 0.00426 1 K 0.00426 1 L 0.02553 6 M 0.04255 10 N 0.09362 22 O 0.08085 19 P 0.02128 5 Q 0.01277 3 R 0.10638 25 S 0.02128 5 T 0.10213 24 U 0.05957 14 V 0.00426 1 W 0.00851 2 Y 0.02979 7 Z 0.00426 1
Prolog
Works with SWI-Prolog.
Only alphabetic codes are computed in uppercase state.
Uses packlist/2 defined there : Run-length encoding#Prolog
<lang Prolog>frequency(File) :-
read_file_to_codes(File, Code, []),
% we only keep alphabetic codes include(my_code_type, Code, LstCharCode),
% we translate char_codes into uppercase atoms. maplist(my_upcase, LstCharCode, LstChar),
% sort and pack the list msort(LstChar, SortLstChar), packList(SortLstChar, Freq), maplist(my_write, Freq).
my_write([Num, Atom]) :-
swritef(A, '%3r', [Num]),
writef('Number of %w :%w\n', [Atom, A]).
my_code_type(Code) :-
code_type(Code, alpha).
my_upcase(CharCode, UpChar) :- char_code(Atom, CharCode), upcase_atom(Atom, UpChar).
- - use_module(library(clpfd)).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % ?- packList([a,a,a,b,c,c,c,d,d,e], L). % L = [[3,a],[1,b],[3,c],[2,d],[1,e]] . % % ?- packList(R, [[3,a],[1,b],[3,c],[2,d],[1,e]]). % R = [a,a,a,b,c,c,c,d,d,e] . %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% packList([],[]).
packList([X],1,X) :- !.
packList([X|Rest],[XRun|Packed]):- run(X,Rest, XRun,RRest), packList(RRest,Packed).
run(Var,[],[1,Var],[]).
run(Var,[Var|LRest],[N1, Var],RRest):- N #> 0, N1 #= N + 1, run(Var,LRest,[N, Var],RRest).
run(Var,[Other|RRest], [1,Var],[Other|RRest]):- dif(Var,Other). </lang>
- Output:
for this file
Number of A : 63 Number of B : 7 Number of C : 53 Number of D : 29 Number of E : 65 ... Number of T : 52 Number of U : 20 Number of V : 10 Number of W : 8 Number of X : 6 Number of Y : 12 true .
PureBasic
Alphabetic codes are converted to uppercase before being used and no other codes are used as part of the calculations.
<lang PureBasic>Procedure countLetters(Array letterCounts(1), textLine.s)
;counts only letters A -> Z, uses index 0 of letterCounts() to keep a total of all counts
Protected i, lineLength = Len(textLine), letter
textLine = UCase(textLine)
For i = 1 To lineLength
letter = Asc(Mid(textLine, i, 1)) - 'A' + 1
If letter >= 1 And letter <= 26
letterCounts(letter) + 1 ;tally individual letter count
letterCounts(0) + 1 ;increment total letter count
EndIf
Next
EndProcedure
If OpenConsole()
Define filename.s, fileID, i
filename = OpenFileRequester("Select text file to examine", "*.txt", "Text (*.txt)|*.txt;|All files (*.*)|*.*", 0)
fileID = 0
If ReadFile(fileID, filename)
Dim letterCounts(26) ;A - Z only, index 0 contains the total of all letter counts
Define textLine.s
While Not Eof(fileID)
textLine = ReadString(fileID)
countLetters(letterCounts(), textLine)
Wend
CloseFile(fileID)
PrintN("File: " + filename + #CRLF$)
PrintN("Letter %Freq Count")
For i = 1 To 26
Print(" " + Chr(64 + i) + " ")
Print(RSet(StrF(100 * letterCounts(i) / letterCounts(0), 1), 5, " ") + " ")
PrintN(Str(letterCounts(i)))
Next
PrintN(#CRLF$ + "Total letter count in file: " + Str(letterCounts(0)))
EndIf
Print(#CRLF$ + #CRLF$ + "Press ENTER to exit"): Input()
CloseConsole()
EndIf</lang>
- Output:
File: D:\_T\Text\dictionary.txt Letter %Freq Count A 7.6 27743 B 2.0 7248 C 4.3 15433 D 3.8 13798 E 11.8 42917 F 1.4 5030 G 2.8 10336 H 2.1 7720 I 8.6 31141 J 0.2 588 K 0.8 2964 L 5.3 19399 M 2.7 9821 N 7.1 25682 O 6.1 22084 P 2.9 10696 Q 0.2 714 R 7.5 27055 S 8.0 28898 T 7.1 25773 U 3.3 12032 V 1.1 4019 W 0.9 3348 X 0.3 1096 Y 1.7 6251 Z 0.3 1177 Total letter count in file: 362963
Python
Using collections.Counter
<lang python>import collections, sys
def filecharcount(openfile):
return sorted(collections.Counter(c for l in openfile for c in l).items())
f = open(sys.argv[1]) print(filecharcount(f))</lang>
Not using collections.Counter
<lang python>import string if hasattr(string, 'ascii_lowercase'):
letters = string.ascii_lowercase # Python 2.2 and later
else:
letters = string.lowercase # Earlier versions
offset = ord('a')
def countletters(file_handle):
"""Traverse a file and compute the number of occurences of each letter
return results as a simple 26 element list of integers."""
results = [0] * len(letters)
for line in file_handle:
for char in line:
char = char.lower()
if char in letters:
results[ord(char) - offset] += 1
# Ordinal minus ordinal of 'a' of any lowercase ASCII letter -> 0..25
return results
if __name__ == "__main__":
sourcedata = open(sys.argv[1])
lettercounts = countletters(sourcedata)
for i in xrange(len(lettercounts)):
print "%s=%d" % (chr(i + ord('a')), lettercounts[i]),</lang>
This example defines the function and provides a sample usage. The if ... __main__... line allows it to be cleanly imported into any other Python code while also allowing it to function as a standalone script. (A very common Python idiom).
Using a numerically indexed array (list) for this is artificial and clutters the code somewhat.
Using defaultdict
<lang python>... from collections import defaultdict def countletters(file_handle):
"""Count occurences of letters and return a dictionary of them
"""
results = defaultdict(int)
for line in file_handle:
for char in line:
if char.lower() in letters:
c = char.lower()
results[c] += 1
return results</lang>
Which eliminates the ungainly fiddling with ordinal values and offsets in function countletters of a previous example above. More importantly it allows the results to be more simply printed using:
<lang python>lettercounts = countletters(sourcedata) for letter,count in lettercounts.iteritems():
print "%s=%s" % (letter, count),</lang>
Again eliminating all fussing with the details of converting letters into list indices.
R
<lang R>letter.frequency <- function(filename) {
file <- paste(readLines(filename), collapse = ) chars <- strsplit(file, NULL)1 summary(factor(chars))
}</lang>
Usage on itself:
<lang R>> source('letter.frequency.r') > letter.frequency('letter.frequency.r')
- , . ' ( ) [ ] { } < = 1 a c d e f h i l L m n N o p q r s t u U y
22 3 2 1 2 6 6 2 2 1 1 3 1 1 9 6 1 14 7 2 7 8 3 4 6 1 3 3 1 8 8 7 3 1 2 </lang>
Racket
<lang racket>
- lang racket
(require math)
(define (letter-frequencies ip)
(count-samples (port->list read-char ip)))
(letter-frequencies (open-input-string "abaabdc")) </lang>
- Output:
'(#\a #\b #\d #\c) '(3 2 1 1)
Using input from a text file: <lang racket> (letter-frequencies (open-input-file "somefile.txt")) </lang>
Raven
<lang Raven>define count_letters use $words
{ } as $wordHash [ ] as $keys [ ] as $vals
$words each chr
dup $wordHash swap get 0 prefer 1 + # stack: chr cnt
swap $wordHash swap set
$wordHash keys copy sort each
dup $keys push
$wordHash swap get $vals push
$keys $vals combine print "\n" print
"test.dat" as $file $file read as $all_data $all_data count_letters</lang>
REXX
version 1
It should be noted that the file being read is read one line at time, so the
line-end characters (presumably the line-feed, carriage return, new-line, or
whatever control characters are being used) are not reported.
These characters could be read and reported if the charin BIF would be used instead of the linein BIF.
Also note that this REXX program is ASCII or EBCDIC independent, but what constitutes a letter is restricted to
the Latin (Roman) alphabet (that is, which characters are considered to be letters of a particular language.
The version of REXX that was used was the English version of Regina REXX. It should be noted that almost all
REXX interpreters assume the English language for such things as determining what characters are considered
letters unless another language is specified (Regina REXX uses an environmental variable for this purpose).
All characters are still counted, whether a letter or not, including non-displayable characters. <lang rexx>/*REXX program counts the occurrences of all characters in a file, & note that*/ /* all Latin alphabet letters are uppercased for counting {Latin} letters.*/ /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/ abc = 'abcdefghijklmnopqrstuvwxyz' /*define an (Latin or English) alphabet*/ abcU= 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' /*define an uppercase version of [↑]. */ parse arg fileID . /*this last char isn't a middle dot: · */ if fileID== then fileID='JUNK.TXT' /*¿none specified? Then use the default*/ totChars=0; totLetters=0 /*count of all chars and of all letters*/ pad=left(,18); pad9=left(,18%2) /*used for the indentations of output. */ @.=0 /*wouldn't it be neat to use Θ instead?*/
do j=1 while lines(fileID)\==0 /*read the file 'til the cows come home*/
rec=linein(fileID) /*get a line/record from the input file*/
/* [↓] process all characters in REC.*/
do k=1 for length(rec) /*examine/count each of the characters.*/
totChars=totChars+1 /*bump count of number of characters. */
c=substr(rec,k,1); @.c=@.c+1 /*Peel off a character; bump its count.*/
if \datatype(c,'M') then iterate /*Not a Latin letter? Get next char.*/
totLetters=totLetters+1 /*bump the count for [Latin] letters. */
upper c /* ◄«««««««««««««««««««««««««««◄ uppercase a Latin character.*/
@..c=@..c+1 /*bump the (Latin) letter's count. */
end /*k*/ /*no Greek glyphs: π Γ Σ µ α ß Φ ε δ σ */
end /*j*/ /*maybe we're ½ done by now, or maybe ¬*/
LL= '(Latin) letter'
w=length(totChars) /*used for right─aligning the counts. */ say 'file ─────' fileId "───── has" j-1 'records and has' totLetters LL"s."; say
do L=0 for 256; c=d2c(L) /*display all none─zero letter counts. */ if @..c==0 then iterate /*A zero count? Then ignore character.*/ say pad9 LL' ' c " (also" translate(c,abc,abcU)') count:' right(@..c,w) end /*L*/ /*we may be in a rut, but not a cañyon.*/
say; say 'file ─────' fileId "───── has" totChars 'unique characters.' say
do #=0 for 256; y=d2c(#) /*display all none─zero char counts. */
if @.y==0 then iterate /*A zero count? Then ignore character.*/
c=d2c(#); ch=c /*C is the character glyph of a char. */
if c<<' ' | #==255 then ch= /*don't show control characters or null*/
if c==' ' then ch='blank' /*show a blank's name.*/
say pad right(ch,5) " ('"d2x(#,2)"'x character count:" right(@.c,w)
end /*#*/ /*255 isn't quite ∞, but sometimes ∙∙∙ */
say /*not a good place for dithering: ░▒▓█ */ say pad pad9 '☼ end─of─list ☼' /*show we are at the end of the list. */
/*stick a fork in it, we're all done. ☻*/</lang>
output when using the (above) REXX program for the input file:
Note that this REXX program works with ASCII or EBCDIC, but the order of the output will
be different because of the order in which EBCDIC and ASCII stores characters.
file ───── countfrq.rex ───── has 42 records and has 1540 (Latin) letters.
(Latin) letter A (also a) count: 133
(Latin) letter B (also b) count: 23
(Latin) letter C (also c) count: 101
(Latin) letter D (also d) count: 55
(Latin) letter E (also e) count: 176
(Latin) letter F (also f) count: 49
(Latin) letter G (also g) count: 23
(Latin) letter H (also h) count: 73
(Latin) letter I (also i) count: 86
(Latin) letter J (also j) count: 6
(Latin) letter K (also k) count: 11
(Latin) letter L (also l) count: 91
(Latin) letter M (also m) count: 20
(Latin) letter N (also n) count: 101
(Latin) letter O (also o) count: 97
(Latin) letter P (also p) count: 35
(Latin) letter Q (also q) count: 4
(Latin) letter R (also r) count: 107
(Latin) letter S (also s) count: 81
(Latin) letter T (also t) count: 164
(Latin) letter U (also u) count: 47
(Latin) letter V (also v) count: 3
(Latin) letter W (also w) count: 16
(Latin) letter X (also x) count: 9
(Latin) letter Y (also y) count: 23
(Latin) letter Z (also z) count: 6
file ───── countfrq.rex ───── has 3186 unique characters.
('02'x character count: 1
('0F'x character count: 2
('11'x character count: 2
('18'x character count: 1
('19'x character count: 1
blank ('20'x character count: 1041
" ('22'x character count: 12
# ('23'x character count: 6
% ('25'x character count: 1
& ('26'x character count: 1
' ('27'x character count: 47
( ('28'x character count: 21
) ('29'x character count: 20
* ('2A'x character count: 78
+ ('2B'x character count: 4
, ('2C'x character count: 16
- ('2D'x character count: 1
. ('2E'x character count: 38
/ ('2F'x character count: 80
0 ('30'x character count: 8
1 ('31'x character count: 10
2 ('32'x character count: 10
5 ('35'x character count: 7
6 ('36'x character count: 2
8 ('38'x character count: 2
9 ('39'x character count: 3
: ('3A'x character count: 5
; ('3B'x character count: 9
< ('3C'x character count: 2
= ('3D'x character count: 38
? ('3F'x character count: 5
@ ('40'x character count: 9
A ('41'x character count: 3
B ('42'x character count: 1
C ('43'x character count: 8
D ('44'x character count: 6
E ('45'x character count: 4
F ('46'x character count: 1
G ('47'x character count: 3
H ('48'x character count: 1
I ('49'x character count: 8
J ('4A'x character count: 2
K ('4B'x character count: 2
L ('4C'x character count: 22
M ('4D'x character count: 2
N ('4E'x character count: 3
O ('4F'x character count: 1
P ('50'x character count: 2
Q ('51'x character count: 1
R ('52'x character count: 3
S ('53'x character count: 1
T ('54'x character count: 6
U ('55'x character count: 4
V ('56'x character count: 1
W ('57'x character count: 1
X ('58'x character count: 4
Y ('59'x character count: 1
Z ('5A'x character count: 1
[ ('5B'x character count: 3
\ ('5C'x character count: 2
] ('5D'x character count: 3
a ('61'x character count: 130
b ('62'x character count: 22
c ('63'x character count: 93
d ('64'x character count: 49
e ('65'x character count: 172
f ('66'x character count: 48
g ('67'x character count: 20
h ('68'x character count: 72
i ('69'x character count: 78
j ('6A'x character count: 4
k ('6B'x character count: 9
l ('6C'x character count: 69
m ('6D'x character count: 18
n ('6E'x character count: 98
o ('6F'x character count: 96
p ('70'x character count: 33
q ('71'x character count: 3
r ('72'x character count: 104
s ('73'x character count: 80
t ('74'x character count: 158
u ('75'x character count: 43
v ('76'x character count: 2
w ('77'x character count: 15
x ('78'x character count: 5
y ('79'x character count: 22
z ('7A'x character count: 5
{ ('7B'x character count: 1
| ('7C'x character count: 1
} ('7D'x character count: 1
~ ('7E'x character count: 76
ñ ('A4'x character count: 1
¿ ('A8'x character count: 1
¬ ('AA'x character count: 1
½ ('AB'x character count: 1
« ('AE'x character count: 27
░ ('B0'x character count: 1
▒ ('B1'x character count: 1
▓ ('B2'x character count: 1
─ ('C4'x character count: 25
█ ('DB'x character count: 1
α ('E0'x character count: 1
ß ('E1'x character count: 1
Γ ('E2'x character count: 1
π ('E3'x character count: 1
Σ ('E4'x character count: 1
σ ('E5'x character count: 1
µ ('E6'x character count: 1
Φ ('E8'x character count: 1
Θ ('E9'x character count: 1
δ ('EB'x character count: 1
∞ ('EC'x character count: 1
ε ('EE'x character count: 1
∙ ('F9'x character count: 3
· ('FA'x character count: 1
☼ end─of─list ☼
Version 2 (for TSO)
<lang rexx>/*REXX program counts the occurences of all characters in a file
- Adapted version 1 for TSO (EXECIO instead of linein)
- No translation to uppercase takes place
- There is no need for tails being hex
- 25.07.2012 Walter Pachl
- /
Parse arg dsn . /*Data set to be processed */
if dsn= Then /*none specified? */
dsn='PRIV.V100(TEST)' /* Use default. */
c.=0 /* Character counts */
"ALLOC FI(IN) DA("dsn") SHR REUSE"
'EXECIO * DISKR IN (STEM L. FINIS'
'FREE FI(IN)'
totChars=0 /*count of the total num of chars*/
totLetters=0 /*count of the total num letters.*/
indent=left(,20) /*used for indentation of output.*/
do j=1 to l.0 /*process all lines */
rec=l.j /*take line number j */
Say '>'rec'<' length(rec) /*that's in PRIV.V100(TEST) */
Say ' E8C44D8FF015674BCDEF'
Say ' 61100711200000000002'
do k=1 for length(rec) /*loop over characters */
totChars=totChars+1 /*Increment total number of chars*/
c=substr(rec,k,1) /*get character number k */
c.c=c.c+1 /*increment the character's count*/
End
End /*maybe we're ½ done by now, or ¬*/
w=length(totChars) /*used for right-aligning counts.*/ say 'file -----' dsn "----- has" j-1 'records.' say 'file -----' dsn "----- has" totChars 'characters.'
do L=0 to 255 /* display nonzero letter counts */
c=d2c(l) /* the character in question */
if c.c>0 &, /* was found in the file */
datatype(c,'M')>0 Then Do /* and is a Latin letter */
say indent "(Latin) letter " c 'count:' right(c.c,w) /* tell */
totLetters=totLetters+c.c /* increment number of letters */
End
End
say 'file -----' dsn "----- has" totLetters '(Latin) letters.'
say ' other characters follow'
other=0
do m=0 to 255 /* now for non-letters */
c=d2c(m) /* the character in question */
y=c2x(c) /* the hex representation */
if c.c>0 &, /* was found in the file */
datatype(c,'M')=0 Then Do /* and is not a Latin letter */
other=other+c.c /* increment count */
_=right(c.c,w) /* prepare output of count */
select /*make the character viewable. */
when c<<' ' | m==255 then say indent "'"y"'x character count:" _
when c==' ' then say indent "blank character count:" _
otherwise say indent " " c 'character count:' _
end
end
end
say 'file -----' dsn "----- has" other 'other characters.'</lang> Output:
>WaA Pa12 :&-: :äüÖ2< 20
E8C44D8FF015674BCDEF
61100711200000000002
file ----- PRIV.V100(TEST) ----- has 1 records.
file ----- PRIV.V100(TEST) ----- has 20 characters.
(Latin) letter a count: 2
(Latin) letter A count: 1
(Latin) letter P count: 1
(Latin) letter W count: 1
file ----- PRIV.V100(TEST) ----- has 5 (Latin) letters.
other characters follow
'00'x character count: 1
'10'x character count: 1
blank character count: 3
& character count: 1
- character count: 1
: character count: 1
: character count: 1
ä character count: 1
ü character count: 1
Ö character count: 1
1 character count: 1
2 character count: 2
file ----- PRIV.V100(TEST) ----- has 15 other characters.
Ring
<lang ring> textData = read("C:\Ring\ReadMe.txt") ln =len(textData) charCount = list(255) totCount = 0
for i =1 to ln
char = ascii(substr(textData,i,1)) charCount[char] = charCount[char] + 1 if char > 31 totCount = totCount + 1 ok
next
for i = 32 to 255
if charCount[i] > 0 see char(i) + " = " + charCount[i] + " " + (charCount[i]/totCount)*100 + " %" + nl ok
next </lang>
Ruby
<lang ruby>def letter_frequency(file)
letters = 'a' .. 'z'
File.read(file) .
split(//) .
group_by {|letter| letter.downcase} .
select {|key, val| letters.include? key} .
collect {|key, val| [key, val.length]}
end
letter_frequency(ARGV[0]).sort_by {|key, val| -val}.each {|pair| p pair}</lang> example output, using the program file as input:
$ ruby letterFrequency.rb letterFrequency.rb ["e", 34] ["l", 20] ["t", 17] ["r", 14] ["a", 12] ["y", 9] ["c", 8] ["i", 7] ["v", 6] ["n", 6] ["f", 6] ["s", 6] ["d", 5] ["p", 5] ["k", 5] ["u", 4] ["o", 4] ["g", 3] ["b", 2] ["h", 2] ["q", 2] ["z", 1] ["w", 1]
Ruby 2.0
<lang ruby>def letter_frequency(file)
freq = Hash.new(0) file.each_char.lazy.grep(/alpha:/).map(&:upcase).each_with_object(freq) do |char, freq_map| freq_map[char] += 1 end
end
letter_frequency(ARGF).sort.each do |letter, frequency|
puts "#{letter}: #{frequency}"
end</lang>
note that this version *should* use less memory, even on a gigantic file. This is done by using lazy enumerables, which ruby 2.0 introduces.
example output, using the (somewhat large) dictionary file as the input. Also note that this versions works on unicode text.
$ ruby letter_frequency.rb /usr/share/dict/words A: 64439 B: 15526 C: 31872 D: 28531 E: 88833 F: 10675 G: 22712 H: 19320 I: 66986 J: 1948 K: 8409 L: 41107 M: 22508 N: 57144 O: 48944 P: 22274 Q: 1524 R: 57347 S: 90113 T: 53006 U: 26118 V: 7989 W: 7530 X: 2124 Y: 12652 Z: 3281 Å: 1 á: 10 â: 6 ä: 7 å: 3 ç: 5 è: 28 é: 144 ê: 6 í: 2 ñ: 8 ó: 8 ô: 2 ö: 16 û: 3 ü: 12
Run BASIC
<lang Runbasic>open "c:\rbp101\public\textFile.txt" for input as #f textData$ = input$(#f, lof( #f)) ln =len(textData$) close #f
dim charCount( 255)
for i =1 to ln
char = asc(mid$(textData$,i,1)) charCount(char) = charCount(char) + 1 if char > 31 then totCount = totCount + 1
next i
for i = 32 to 255 if charCount(i) > 0 then print "Ascii:";using("###",i);" char:";chr$(i);" Count:";using("#######",charCount(i));" ";using("##.#",(charCount(i) / totCount) * 100);"%" next i</lang>
Output uses this program to count itself:
Ascii: 32 char: Count: 76 16.1% Ascii: 34 char:" Count: 18 3.8% Ascii: 35 char:# Count: 17 3.6% Ascii: 36 char:$ Count: 6 1.3% Ascii: 37 char:% Count: 1 0.2% Ascii: 40 char:( Count: 16 3.4% Ascii: 41 char:) Count: 16 3.4% Ascii: 42 char:* Count: 1 0.2% Ascii: 43 char:+ Count: 2 0.4% Ascii: 44 char:, Count: 6 1.3% Ascii: 46 char:. Count: 2 0.4% Ascii: 47 char:/ Count: 1 0.2% Ascii: 48 char:0 Count: 4 0.8% Ascii: 49 char:1 Count: 8 1.7% Ascii: 50 char:2 Count: 3 0.6% Ascii: 51 char:3 Count: 2 0.4% Ascii: 53 char:5 Count: 4 0.8% Ascii: 58 char:: Count: 4 0.8% Ascii: 59 char:; Count: 8 1.7% Ascii: 61 char:= Count: 7 1.5% Ascii: 62 char:> Count: 2 0.4% Ascii: 65 char:A Count: 1 0.2% Ascii: 67 char:C Count: 10 2.1% Ascii: 68 char:D Count: 3 0.6% Ascii: 70 char:F Count: 1 0.2% Ascii: 92 char:\ Count: 3 0.6% Ascii: 97 char:a Count: 19 4.0% Ascii: 98 char:b Count: 2 0.4% Ascii: 99 char:c Count: 17 3.6% Ascii:100 char:d Count: 3 0.6% Ascii:101 char:e Count: 13 2.7% Ascii:102 char:f Count: 10 2.1% Ascii:103 char:g Count: 3 0.6% Ascii:104 char:h Count: 14 3.0% Ascii:105 char:i Count: 24 5.1% Ascii:108 char:l Count: 7 1.5% Ascii:109 char:m Count: 2 0.4% Ascii:110 char:n Count: 25 5.3% Ascii:111 char:o Count: 21 4.4% Ascii:112 char:p Count: 6 1.3% Ascii:114 char:r Count: 17 3.6% Ascii:115 char:s Count: 7 1.5% Ascii:116 char:t Count: 38 8.0% Ascii:117 char:u Count: 16 3.4% Ascii:120 char:x Count: 7 1.5%
Rust
Works with all UTF-8 characters <lang rust>use std::collections::btree_map::BTreeMap; use std::{env, process}; use std::io::{self, Read, Write}; use std::fmt::Display; use std::fs::File;
fn main() {
let filename = env::args().nth(1)
.ok_or("Please supply a file name")
.unwrap_or_else(|e| exit_err(e, 1));
let mut buf = String::new(); let mut count = BTreeMap::new();
File::open(&filename)
.unwrap_or_else(|e| exit_err(e, 2))
.read_to_string(&mut buf)
.unwrap_or_else(|e| exit_err(e, 3));
for c in buf.chars() {
*count.entry(c).or_insert(0) += 1;
}
println!("Number of occurences per character");
for (ch, count) in &count {
println!("{:?}: {}", ch, count);
}
}
- [inline]
fn exit_err<T>(msg: T, code: i32) -> ! where T: Display {
writeln!(&mut io::stderr(), "{}", msg).expect("Could not write to stderr");
process::exit(code)
}</lang>
Output when run on source file:
Number of occurences per character
'\n': 35
' ': 167
'!': 4
'\"': 10
'#': 1
'&': 4
'(': 25
')': 25
'*': 1
'+': 1
',': 12
'-': 1
'.': 10
'0': 1
'1': 3
'2': 2
'3': 2
':': 37
';': 13
'<': 1
'=': 4
'>': 2
'?': 1
'B': 2
'C': 1
'D': 2
'F': 2
'M': 2
'N': 1
'P': 1
'R': 1
'S': 1
'T': 5
'W': 1
'[': 1
']': 1
'_': 15
'a': 20
'b': 5
'c': 22
'd': 12
'e': 75
'f': 14
'g': 5
'h': 6
'i': 29
'k': 1
'l': 23
'm': 13
'n': 36
'o': 28
'p': 17
'r': 45
's': 33
't': 42
'u': 24
'v': 2
'w': 8
'x': 6
'y': 4
'{': 9
'|': 6
'}': 9
Scala
<lang scala>import io.Source.fromFile
def letterFrequencies(filename: String) =
fromFile(filename).mkString groupBy (c => c) mapValues (_.length)</lang>
Scheme
Using guile scheme 2.0.11.
Note that this prints the scheme representations of characters in no particular order.
<lang scheme>(use-modules (ice-9 format))
(define (char-freq port table)
(if (eof-object? (peek-char port)) table (char-freq port (add-char (read-char port) table))))
(define (add-char char table)
(cond ((null? table) (list (list char 1))) ((eq? (caar table) char) (cons (list char (+ (cadar table) 1)) (cdr table))) (#t (cons (car table) (add-char char (cdr table))))))
(define (format-table table)
(for-each (lambda (t) (format #t "~10s~10d~%" (car t) (cadr t))) table))
(define (print-freq filename)
(format-table (char-freq (open-input-file filename) '())))
(print-freq "letter-frequency.scm")</lang>
Output when reading own source:
#\( 45 #\u 5 #\s 9 #\e 47 #\- 19 #\m 9 #\o 16 #\d 19 #\l 25 #\space 83 #\i 15 #\c 28 #\9 1 #\f 20 #\r 39 #\a 47 #\t 36 #\) 45 #\newline 21 #\n 15 #\h 14 #\q 7 #\p 9 #\b 16 #\j 1 #\? 3 #\k 1 #\1 4 #\+ 1 #\# 2 #\" 4 #\~ 3 #\0 2 #\% 1 #\' 1 #\y 1 #\. 1
An implementation for CHICKEN scheme:
<lang scheme> (with-input-from-string "foobar"
(lambda ()
(port-fold (lambda (x s)
(alist-update x
(add1 (alist-ref x s eq? 0))
s))
'()
read-char)))
</lang>
which shows: ((#\f . 1) (#\o . 2) (#\b . 1) (#\a . 1) (#\r . 1))
Seed7
<lang seed7>$ include "seed7_05.s7i";
const type: charHash is hash [char] integer;
const proc: main is func
local
var charHash: numberOfChars is charHash.EMPTY_HASH;
var char: ch is ' ';
begin
ch := getc(IN);
while ch <> EOF do
if ch in numberOfChars then
incr(numberOfChars[ch]);
else
numberOfChars @:= [ch] 1;
end if;
ch := getc(IN);
end while;
for ch range sort(keys(numberOfChars)) do
writeln(ch <& " " <& numberOfChars[ch]);
end for;
end func;</lang>
Output when the program uses itself as input:
22 129 " 4 $ 1 & 2 ' 2 ( 6 ) 6 . 2 0 1 ... s 21 t 9 u 9 v 2 w 3 y 2
Sidef
<lang ruby>func letter_frequency(File file) {
file.read.chars.grep{.match(/alpha:/)} \
.group_by {|letter| letter.downcase} \
.map_val {|_, val| val.len} \
.sort_by {|_, val| -val}
}
var top = letter_frequency(File(__FILE__)) top.each{|pair| say "#{pair[0]}: #{pair[1]}"}</lang>
- Output:
e: 22 l: 17 a: 16 t: 14 r: 14 p: 12 f: 8 i: 8 n: 7 c: 6 u: 6 o: 6 v: 6 y: 5 s: 5 h: 3 w: 2 q: 2 b: 2 m: 2 g: 2 d: 1
SIMPOL
Example: open a text file and compute letter frequency. <lang simpol>constant iBUFSIZE 500
function main(string filename)
fsfileinputstream fpi integer e, i, aval, zval, cval string s, buf, c array chars
e = 0
fpi =@ fsfileinputstream.new(filename, error=e)
if fpi =@= .nul
s = "Error, file """ + filename + """ not found{d}{a}"
else
chars =@ array.new()
aval = .charval("a")
zval = .charval("z")
i = 1
while i <= 26
chars[i] = 0
i = i + 1
end while
buf = .lcase(fpi.getstring(iBUFSIZE, 1))
while not fpi.endofdata and buf > ""
i = 1
while i <= .len(buf)
c = .substr(buf, i, 1)
cval = .charval(c)
if cval >= aval and cval <= zval
chars[cval - aval + 1] = chars[cval - aval + 1] + 1
end if
i = i + 1
end while
buf = .lcase(fpi.getstring(iBUFSIZE, 1))
end while
s = "Character counts for """ + filename + """{d}{a}"
i = 1
while i <= chars.count()
s = s + .char(aval + i - 1) + ": " + .tostr(chars[i], 10) + "{d}{a}"
i = i + 1
end while
end if
end function s</lang>
As this was being created I realized that in [SIMPOL] I wouldn't have done it this way (in fact, I wrote it differently the first time and had to go back and change it to use an array afterward). In [SIMPOL] we would have used the set object. It acts similarly to a single-dimensional array, but can also use various set operations, such as difference, unite, intersect, etc. One of th einteresting things is that each unique value is stored only once, and the number of duplicates is stored with it. The sample then looks a little cleaner:
<lang simpol>constant iBUFSIZE 500
function main(string filename)
fsfileinputstream fpi integer e, i, aval, zval string s, buf, c set chars
e = 0
fpi =@ fsfileinputstream.new(filename, error=e)
if fpi =@= .nul
s = "Error, file """ + filename + """ not found{d}{a}"
else
chars =@ set.new()
aval = .charval("a")
zval = .charval("z")
buf = .lcase(fpi.getstring(iBUFSIZE, 1))
while not fpi.endofdata and buf > ""
i = 1
while i <= .len(buf)
c = .substr(buf, i, 1)
if .charval(c) >= aval and .charval(c) <= zval
chars.addvalue(c)
end if
i = i + 1
end while
buf = .lcase(fpi.getstring(iBUFSIZE, 1))
end while
s = "Character counts for """ + filename + """{d}{a}"
i = 1
while i <= chars.count()
s = s + chars[i] + ": " + .tostr(chars.valuecount(chars[i]), 10) + "{d}{a}"
i = i + 1
end while
end if
end function s</lang>
The final stage simply reads the totals for each character. One caveat, if a character is unrepresented, then it will not show up at all in this second implementation.
Tcl
<lang tcl>proc letterHistogram {fileName} {
# Initialize table (in case of short texts without every letter)
for {set i 97} {$i<=122} {incr i} {
set frequency([format %c $i]) 0
}
# Iterate over characters in file
set f [open $fileName]
foreach c [split [read $f] ""] {
# Count them if they're alphabetic
if {[string is alpha $c]} {
incr frequency([string tolower $c])
}
}
close $f
# Print the histogram
parray frequency
}
letterHistogram the/sample.txt</lang>
TUSCRIPT
<lang tuscript> $$ MODE TUSCRIPT words = REQUEST ("http://www.puzzlers.org/pub/wordlists/unixdict.txt")
DICT letters create MODE {} COMPILE LOOP word=words
letters=SPLIT (word,|":?:") LOOP letter=letters DICT letters ADD/QUIET/COUNT letter ENDLOOP
ENDLOOP ENDCOMPILE DICT letters unload letter,size,cnt
index =DIGIT_INDEX (cnt) index =REVERSE (index) letter =INDEX_SORT (letter,index) cnt =INDEX_SORT (cnt,index) frequency=JOIN (letter," --- ",cnt)
- {frequency}
</lang> Output:
e --- 20144 a --- 16421 i --- 13980 r --- 13436 t --- 12836 o --- 12738 n --- 12097 s --- 10210 l --- 10061 c --- 8216 u --- 6489 m --- 5828 d --- 5799 p --- 5516 h --- 5208 g --- 4129 b --- 4115 y --- 3633 f --- 2662 w --- 1968 k --- 1925 v --- 1902 x --- 617 z --- 433 j --- 430 q --- 378 ' --- 105 . --- 6 & --- 6 1 --- 2 9 --- 1 8 --- 1 7 --- 1 6 --- 1 5 --- 1 4 --- 1 3 --- 1 2 --- 1 0 --- 1
TXR
TXR Extraction Language plus TXR Lisp
<lang txr>@(do (defvar h (hash :equal-based))) @(repeat) @(coll :vars ())@\
@{letter /[A-Za-z]/}@(filter :upcase letter)@\
@(do (inc [h letter 0]))@\
@(end) @(end) @(do (dohash (key value h)
(format t "~a: ~a\n" key value)))</lang>
- Output:
$ ./txr letterfreq.txr /usr/share/dict/words A: 64123 B: 15524 C: 31569 [ ... abridged ... ] X: 2124 Y: 12507 Z: 3238
TXR Lisp
<lang txrlisp>(let* ((s (open-file "/usr/share/dict/words" "r"))
(chrs [keep-if* chr-isalpha (gun (get-char s))])
(h [group-reduce (hash) chr-toupper (op succ @1) chrs 0]))
(dohash (key value h)
(put-line `@key: @value`)))</lang>
Vala
Counts every character except new line character. <lang vala> using Gee;
void main(string[] args){
string filename = args[1]; var file = FileStream.open(filename, "r");
var counter = new HashMap<char, int>();
string line = file.read_line();
while (line != null){
for (int x = 0; x < line.length; x++){
counter[line[x]] = counter[line[x]] + 1;
}
line = file.read_line(); }
foreach (var elem in counter.entries){
stdout.printf("%c occured %d times\n", elem.key, elem.value);
}
} </lang>
Sample output (run on its own source code) with several lines omitted:
v occured 5 times , occured 4 times w occured 2 times occured 19 times S occured 1 times 1 occured 2 times ! occured 1 times k occured 1 times l occured 22 times
VBA
<lang VBA> Public Sub LetterFrequency(fname) 'count number of letters in text file "fname" (ASCII-coded) 'note: we count all characters but print only the letter frequencies
Dim Freqs(255) As Long Dim abyte As Byte Dim ascal as Byte 'ascii code for lowercase a Dim ascau as Byte 'ascii code for uppercase a
'try to open the file On Error GoTo CantOpen Open fname For Input As #1 On Error GoTo 0
'initialize For i = 0 To 255
Freqs(i) = 0
Next i
'process file byte-per-byte While Not EOF(1)
abyte = Asc(Input(1, #1)) Freqs(abyte) = Freqs(abyte) + 1
Wend Close #1
'add lower and upper case together and print result Debug.Print "Frequencies:" ascal = Asc("a") ascau = Asc("A") For i = 0 To 25
Debug.Print Chr$(ascal + i), Freqs(ascal + i) + Freqs(ascau + i)
Next i Exit Sub
CantOpen:
Debug.Print "can't find or read the file "; fname Close
End Sub </lang>
Output:
LetterFrequency "d:\largetext.txt" Frequencies: a 24102 b 4985 c 4551 d 19127 e 61276 f 2734 g 10661 h 8243 i 21589 j 4904 k 7186 l 12026 m 7454 n 31963 o 19021 p 4960 q 37 r 21166 s 13403 t 21090 u 6117 v 8612 w 5017 x 168 y 299 z 4159
VBScript
<lang vb> filepath = "SPECIFY FILE PATH HERE"
Set objfso = CreateObject("Scripting.FileSystemObject") Set objdict = CreateObject("Scripting.Dictionary") Set objfile = objfso.OpenTextFile(filepath,1)
txt = objfile.ReadAll
For i = 1 To Len(txt) char = Mid(txt,i,1) If objdict.Exists(char) Then objdict.Item(char) = objdict.Item(char) + 1 Else objdict.Add char,1 End If Next
For Each key In objdict.Keys WScript.StdOut.WriteLine key & " = " & objdict.Item(key) Next
objfile.Close Set objfso = Nothing Set objdict = Nothing </lang>
Vedit macro language
<lang vedit>File_Open("c:\txt\a_text_file.txt") Update()
for (#1='A'; #1<='Z'; #1++) {
Out_Reg(103) Char_Dump(#1,NOCR) Out_Reg(CLEAR) #2 = Search(@103, BEGIN+ALL+NOERR) Message(@103) Num_Type(#2)
}</lang>
Example output:
A 76 B 23 C 51 D 64 E 192 F 51 G 32 H 59 I 146 J 1 K 9 L 73 M 34 N 94 O 113 P 27 Q 1 R 92 S 89 T 138 U 63 V 26 W 35 X 16 Y 16 Z 2
Whitespace
<lang Whitespace>
</lang>
<lang asm>push 127
- Initialize a slot in the heap for each ASCII character.
0:
dup push 0 store push 1 sub dup jn 1 jump 0
- Read until EOF, incrementing the relevant heap slot.
1:
push 0 dup ichr load dup jn 2 ; Done reading, proceed to print. dup load push 1 add store jump 1
- Stack is [-1 -1], but [0] would be nice.
2:
sub
- Print characters with tallies greater than 0.
3:
push 1 add dup push 128 sub jz 4 ; All done. dup load jz 3 ; Don't print if no occurrences. dup ochr ; Display the character, push 32 ochr ; a space, dup load onum ; its frequency, push 10 ochr ; and a newline. jump 3
4:
pop exit</lang>
- Output:
$ cat freq.ws | wspace freq.ws 64 55 119
XPL0
This takes advantage of DOS's ability to redirect input from a file to the keyboard. The input file must be terminated with an end-of-file character ($1A). Usage: count <filename.ext
<lang XPL0>include c:\cxpl\codes; \intrinsic 'code' declarations int A(256), C, I; [for C:= 0 to 256-1 do A(C):= 0; repeat C:= ChIn(1); \device 1 doesn't buffer nor echo chars
A(C):= A(C)+1; \count character
until C=\EOF\$1A; C:= 0; for I:= 0 to 128-1 do \only show 7-bit ASCII
[ChOut(0, \tab\9);
case C of
$0A: ChOut(6, $19); \line feed = down arrow
$0D: ChOut(6, $1B) \carriage return = left arrow
other ChOut(6, C); \all other characters display on device 6
ChOut(0, ^ );
IntOut(0, A(C)); \show count
C:= C+16; \columnar order
if (I&7) = 7 then [CrLf(0); C:= C-8*16+1];
];
]</lang>
Example output of count.xpl counting itself:
zkl
<lang zkl>fcn ccnt(textInBitBucket){
letters:=["a".."z"].pump(List().write,0); // array of 26 zeros
textInBitBucket.howza(0).pump(Void,'wrap(c){ // pump text as ints
if(97<=c<=122) c-=97;
else if(65<=c<=90) c-=65;
else return(Void.Skip);
letters[c]+=1
});
sum:=letters.sum(); println(sum," letters");
letters.enumerate().pump(List,'wrap([(c,n)]){
"%s(%d:%d%)".fmt((c+65).toChar(),n,n*100/sum)})
.concat(",").println();
}
ccnt(Data(0,Int,"This is a test")); ccnt(File("dict.txt").read());</lang>
- Output:
11 letters A(1:9%),B(0:0%),C(0:0%),D(0:0%),E(1:9%),F(0:0%),G(0:0%),H(1:9%),I(2:18%),J(0:0%),K(0:0%),L(0:0%),M(0:0%),N(0:0%),O(0:0%),P(0:0%),Q(0:0%),R(0:0%),S(3:27%),T(3:27%),U(0:0%),V(0:0%),W(0:0%),X(0:0%),Y(0:0%),Z(0:0%) 181171 letters A(16421:9%),B(4115:2%),C(8216:4%),D(5799:3%),E(20144:11%),F(2662:1%),G(4129:2%),H(5208:2%),I(13980:7%),J(430:0%),K(1925:1%),L(10061:5%),M(5828:3%),N(12097:6%),O(12738:7%),P(5516:3%),Q(378:0%),R(13436:7%),S(10210:5%),T(12836:7%),U(6489:3%),V(1902:1%),W(1968:1%),X(617:0%),Y(3633:2%),Z(433:0%)
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