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Fractran: Difference between revisions

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Fractran (view source)

Revision as of 20:41, 11 August 2021

6 bytes added ,  2 years ago
m
→‎{{header|REXX}}: added/changed comments and whitespace, optimized a DO loop.
m (fixed HTML tag.)
m (→‎{{header|REXX}}: added/changed comments and whitespace, optimized a DO loop.)
Line 3,525:
numeric digits 2000 /*be able to handle larger numbers. */
parse arg N terms fracs /*obtain optional arguments from the CL*/
if N=='' | N=="," then N= 2 2 /*Not specified? Then use the default.*/
if terms=='' | terms=="," then terms= 100 /* " " " " " " */
if fracs='' then fracs= '"17/91, 78/85, 19/51, 23/38, 29/33, 77/29, 95/23,'",
'77/19, 1/17, 11/13, 13/11, 15/14, 15/2, 55/1'
/* [↑] The default for the fractions. */
f= space(fracs, 0) /*remove all blanks from the FRACS list*/
do #=1 while f\==''; parse var f n.# '"/'" d.# "',"' f
end /*#*/ /* [↑] parse all the fractions in list*/
#= # - 1 /*the number of fractions just found. */
say # 'fractions:' fracs /*display number and actual fractions. */
Line 3,538:
say terms ' terms are being shown:' /*display a kind of header/title. */
 
do j=1 for terms /*perform the DO loop for each term. */
do k=1 for # /* " " " " " " fraction*/
if N // d.k \== 0 then iterate /*Not an integer? Then ignore it. */
say right('term' j, 35) "──► " N /*display the Nth term with the N. */
N= N % d.k * n.k /*calculate next term (use %≡integer ÷)*/
leave /*go start calculating the next term. */
end /*k*/ /* [↑] if an integer, we found a new N*/
end /*j*/ /*stick a fork in it, we're all done. */</lang>
{{out|output|text=&nbsp; when using the default input:}}
<pre style="height:63ex">
Line 3,656:
Programming note: &nbsp; if the number of terms specified (the 2<sup>nd</sup> argument) is negative, then only powers of two are displayed.
<lang rexx>/*REXX program runs FRACTRAN for a given set of fractions and from a specified N. */
numeric digits 999; d= digits(); w= length( digits() d) /*be able to handle gihugeic numbers. */
parse arg N terms fracs /*obtain optional arguments from the CL*/
if N=='' | N=="," then N= 2 /*Not specified? Then use the default.*/
if terms=='' | terms=="," then terms= 100 /* " " " " " " */
if fracs='' then fracs= '"17/91, 78/85, 19/51, 23/38, 29/33, 77/29, 95/23,'",
'77/19, 1/17, 11/13, 13/11, 15/14, 15/2, 55/1'
/* [↑] The default for the fractions. */
f= space(fracs, 0) /*remove all blanks from the FRACS list*/
do #=1 while f\==''; parse var f n.# '"/'" d.# "',"' f
end /*#*/ /* [↑] parse all the fractions in list*/
#= # - 1 /*adjust the number of fractions found.*/
tell= terms>0 /*flag: show number or a power of 2.*/
!.= 0; _= 1 /*the default value for powers of 2. */
if \tell then do p=1 until length(_)>digits()d; _= _ + _; !._= 1
if p==1 then @._= left('', w + 9) "2**"left(p, w) ' '
else @._= '(prime' right(p, w)") 2**"left(p, w) ' '
Line 3,678:
if tell then say terms ' terms are being shown:' /*display header.*/
else say 'only powers of two are being shown:' /* " " */
q= '(max digits used:' /*a literal used in the SAY below. */
 
do j=1 for abs(terms) /*perform DO loop once for each term. */
do k=1 for # /* " " " " " " fraction*/
if N // d.k \== 0 then iterate /*Not an integer? Then ignore it. */
if tell then say right('term' j, 35) "──► " N /*display Nth term and N.*/
else if !.N then say right('term' j,15) "──►" @.N q right(L,w)") " N
N= N % d.k * n.k /*calculate next term (use %≡integer ÷)*/
L= max(L, length(N) ) /*the maximum number of decimal digits.*/
leave /*go start calculating the next term. */
end /*k*/ /* [↑] if an integer, we found a new N*/
end /*j*/ /*stick a fork in it, we're done. */</lang>
{{out|output|text=&nbsp; when using the input of: &nbsp; &nbsp; <tt> , &nbsp; -50000000 </tt>}}
<br>(negative fifty million)
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