45 lines
1.5 KiB
Plaintext
45 lines
1.5 KiB
Plaintext
BEGIN # Modified random distribution - translation of the Wren sample #
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next random; # initialise the random number generator #
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PROC rng = ( PROC(REAL)REAL modifier )REAL:
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BEGIN
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REAL r1, r2;
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WHILE
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r1 := random;
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r2 := random;
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r2 >= modifier( r1 )
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DO SKIP OD;
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r1
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END # rng # ;
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PROC modifier = ( REAL x )REAL: 2 * ABS ( 0.5 - x );
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INT n = 100 000;
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INT num bins = 21;
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REAL bin size = 1 / num bins;
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CHAR hist char = "#";
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INT hist char size = 125;
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[ 0 : num bins - 1 ]INT bins ; FOR i FROM LWB bins TO UPB bins DO bins[ i ] := 0 OD;
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FOR i FROM 0 TO n DO
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bins[ ENTIER ( rng( modifier ) / bin size ) ] +:= 1
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OD;
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PROC f2 = ( REAL v )STRING: # formatting routine #
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BEGIN
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STRING result := fixed( ABS v, 0, 2 );
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IF result[ LWB result ] = "." THEN "0" +=: result FI;
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IF v < 0 THEN "-" +=: result FI;
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result
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END # FMT # ;
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print( ( "Modified random distribution with ", whole( n, 0 ), " samples in range [0, 1):", newline ) );
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print( ( " Range Number of samples within that range", newline ) );
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FOR i FROM LWB bins TO UPB bins DO
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STRING hist = hist char * ROUND ( bins[ i ] / hist char size );
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print( ( f2( bin size * i ), " ..< " ) );
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print( ( f2( bin size * ( i + 1 ) ), " ", whole( bins[ i ], -5 ), " ", hist, newline ) )
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OD
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END
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