That code doesn't throw any errors. It might not give the output you want, but then you should at least tell us what output it produced, and what you wanted it to print instead.

In this case reading perlreftut and applying what you learn there should solve your problem.

thank you for your helps.

#!/usr/bin/perl -w
use strict;
my %genome1 = (
   a => [ 10, 15 ],
   b => [  3,  7 ],
   c => [  9, 14 ],
);

my %genome2 = (
   d => [  3, 21 ],
   a => [  3,  4 ],
   g => [  5, 10 ],
   b => [  2,  7 ],
);

for (keys(%genome1)) {
   if ($genome2{$_}) {
      print("$genome1{$_} and $genome2{$_}\n");
   }
}
[download]

we have a in each of hashes (3,4) and (10,15).i want to calculate the slope of the line between (3,4) and (10,15), it means (15-4)/(10-3) or for b we have (2,7) and (3,7),i want (7-7)/(3-2) as output.m=(y2-y1)/(x2-x1).but i dont know how i have to define x and y for numbers in hashes.

So, did you read perlreftut?

We're not here to write the code for you, but to help you to learn enough Perl and programminig so that you can do it yourself.

Perl 6 - second systems done right

i want (7-7)/(3-2) as output.

Is this what you want?

for (keys(%genome1)) {
   if ($genome2{$_}) {
      print "for ".$_." it is (".${$genome1{$_}}[1]."-".
      ${$genome2{$_}}[1].")/(".${$genome1{$_}}[0]."-".${$genome2{$_}}[
+0].")\n";
   }
}
[download]