Modified random distribution: Difference between revisions
Ada version
(Added missing "randomize" (needed to get different "random" values for each run).) |
(Ada version) |
||
Line 22:
Show your output here, on this page.
<br><br>
=={{header|Ada}}==
<lang Ada>with Ada.Text_Io;
with Ada.Numerics.Float_Random;
with Ada.Strings.Fixed;
procedure Modified_Distribution is
Observations : constant := 20_000;
Buckets : constant := 25;
Divider : constant := 12;
Char : constant Character := '*';
generic
with function Modifier (X : Float) return Float;
package Generic_Random is
function Random return Float;
end Generic_Random;
package body Generic_Random is
package Float_Random renames Ada.Numerics.Float_Random;
Generator : Float_Random.Generator;
function Random return Float is
Random_1 : Float;
Random_2 : Float;
begin
loop
Random_1 := Float_Random.Random (Generator);
Random_2 := Float_Random.Random (Generator);
if Random_2 < Modifier (Random_1) then
return Random_1;
end if;
end loop;
end Random;
begin
Float_Random.Reset (Generator);
end Generic_Random;
generic
Buckets : in Positive;
package Histograms is
type Bucket_Index is new Positive range 1 .. Buckets;
Bucket_Width : constant Float := 1.0 / Float (Buckets);
procedure Clean;
procedure Increment_Bucket (Observation : Float);
function Observations_In (Bucket : Bucket_Index) return Natural;
function To_Bucket (X : Float) return Bucket_Index;
function Range_Image (Bucket : Bucket_Index) return String;
end Histograms;
package body Histograms is
Hist : array (Bucket_Index) of Natural := (others => 0);
procedure Clean is
begin
Hist := (others => 0);
end Clean;
procedure Increment_Bucket (Observation : Float) is
Bin : constant Bucket_Index := To_Bucket (Observation);
begin
Hist (Bin) := Hist (Bin) + 1;
end Increment_Bucket;
function Observations_In (Bucket : Bucket_Index) return Natural
is (Hist (Bucket));
function To_Bucket (X : Float) return Bucket_Index
is (1 + Bucket_Index'Base (Float'Floor (X / Bucket_Width)));
function Range_Image (Bucket : Bucket_Index) return String is
package Float_Io is new Ada.Text_Io.Float_Io (Float);
Image : String := "F.FF..L.LL";
First : constant Float := Float (Bucket - 1) / Float (Buckets);
Last : constant Float := Float (Bucket - 1 + 1) / Float (Buckets);
begin
Float_Io.Put (Image (1 .. 4), First, Exp => 0, Aft => 2);
Float_Io.Put (Image (7 .. 10), Last, Exp => 0, Aft => 2);
return Image;
end Range_Image;
begin
Clean;
end Histograms;
function Modifier (X : Float) return Float
is (if X in Float'First .. 0.5
then 2.0 * (0.5 - X)
else 2.0 * (X - 0.5));
package Modified_Random is
new Generic_Random (Modifier => Modifier);
package Histogram_20 is
new Histograms (Buckets => Buckets);
function Column (Height : Natural; Char : Character) return String
renames Ada.Strings.Fixed."*";
use Ada.Text_Io;
begin
for N in 1 .. Observations loop
Histogram_20.Increment_Bucket (Modified_Random.Random);
end loop;
Put ("Range Observations: "); Put (Observations'Image);
Put (" Buckets: "); Put (Buckets'Image);
New_Line;
for I in Histogram_20.Bucket_Index'Range loop
Put (Histogram_20.Range_Image (I));
Put (" ");
Put (Column (Histogram_20.Observations_In (I) / Divider, Char));
New_Line;
end loop;
end Modified_Distribution;</lang>
{{out}}
<pre>Range Observations: 20000 Buckets: 25
0.00..0.04 ****************************************************************************
0.04..0.08 ************************************************************************
0.08..0.12 **************************************************************
0.12..0.16 **********************************************************
0.16..0.20 **************************************************
0.20..0.24 ******************************************
0.24..0.28 ***************************************
0.28..0.32 *******************************
0.32..0.36 *************************
0.36..0.40 *******************
0.40..0.44 ************
0.44..0.48 *****
0.48..0.52 *
0.52..0.56 *******
0.56..0.60 ***********
0.60..0.64 ********************
0.64..0.68 ***************************
0.68..0.72 **********************************
0.72..0.76 **************************************
0.76..0.80 ********************************************
0.80..0.84 *************************************************
0.84..0.88 **********************************************************
0.88..0.92 ****************************************************************
0.92..0.96 *******************************************************************
0.96..1.00 ************************************************************************</pre>
=={{header|Factor}}==
| |||