Re: Randomly generating histograms

narse,

Well, there may be other things that bound you (this example just uses integers and can have dupes) but a simplistic brute force approach would be:

#!/usr/bin/perl -wd

use strict;
my $tot = 0;
my $i   = 0;
my $x   = 0;
my @array;

while( $tot < 100 ) {
   my $x = int rand( 100 );
   $x = ( $tot + $x > 100 ) ? 100 - $tot : $x;
   $array[$i] = $x;
   $i++;
   $tot += $x;
}

$tot = 0;
foreach( @array ) {
   print $_, "\n";
   $tot += $_;
}
print "Total is ", $tot, "\n";
[download]

But I'm sure there are prettier approaches. But start with rand and perlfaq4 for ideas.

<code> -derby

Comment on Re: Randomly generating histograms Download Code

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Re: Re: Randomly generating histograms by narse (Pilgrim) on Mar 25, 2002 at 16:13 UTC
This is similar to the method I am using at the moment for testing. The problem I have is the first entries in the array always have the largest numbers, while the last ones are nearly always 0. I mixed this up some by randomizing which array index each value goes into but I'm hoping to find something thats a little more random. Thanks tho.	[reply]
Re: Re: Re: Randomly generating histograms by derby (Abbot) on Mar 25, 2002 at 16:56 UTC
This is completely hackish but loop for x number of times (12, 100?) before using the values of rand: `$x = int rand( 100 ) for ( 1 .. 12 ); $x = 0;` [download] update: Or better yet. After you have the array filled, shuffle it as described in perlfaq4. -derby	[reply] [d/l]
Re: Re: Randomly generating histograms by narse (Pilgrim) on Mar 26, 2002 at 22:12 UTC
I probably didn't express what I was hoping to do well enough so not many people hit on what I was asking. Thanks for the responses none the less. I found a method elsewhere that does what I want very well and is easier to impliment than the others that I saw. Here it is: `#!/usr/bin/perl -w use strict; my @arr; map { $arr[rand 10]++ } 0..99; print join(' ', @arr), "\n";` [download]	[reply] [d/l]