#! perl -slw use strict; my $dna = do{ local $/; }; $dna =~ tr[\n][]d; my %counts; ++$counts{ substr $dna, $_, 1 } for 0 .. 199; for my $offset ( 0 .. length( $dna )-200 ) { printf "range: %d .. %d A:%d C:%d G:%d T:%d\n", $offset, $offset+199, @counts{ qw[ A C G T ] }; --$counts{ substr $dna, $offset, 1 }; ++$counts{ substr $dna, $offset+200, 1 }; } __DATA__ TGCCATCGCGCCAGGAGGGAAGACCAGTTGCTCTGGGTAAATCAGCCGTGAGCGTATCTGTCCCTCTTATAATTAGGAGTTTAAACTCTACGATGTTACC ATCCTTGAATCAGGTATATACCGCACTGAAACATCGTCGGCTTTGGGCTCATTCGCTACCCTGTCGCTGATATGCGATCTATTCTACATATGCGGGGCCA CCCAATGTCGATTGTCATGAGGAGGGGGTCATAACGACTCACTATAGGACCAGCACGTCCGGTTGCGCTGAGTAAAATAGAGCTACAAAAGACACAGTAC TCCAAGATGTAAAGGGGAAGACGGGACCTGGGTCGGGGGCGCAACTTCACTGAGCTTTTAACCTTGCGCGCATGCGAGAGCCTTTCCGCTTAGGAAATGC TGTAAGATCAAGTGGTAGGACTATTGAGAGGTCTTACCTTGCCGCAGCAACGTGGACGGCGACCGGATAATTTAAGGCCGACATTCAATATAGAATGTCA GGGAGCAGAACTGTATCCCAAATGCTAGTTGTAGGTGTACGAGCGCACCTGGGGACCTATCGCTCCGACGGGGTCTGCGTAGCCCATACATCCTGCCAGC ACTGGGGCTATTGAACGGTCAATCCGTAATGTACTCGCTGAATGCTCAGGGATTCCTTAATCTTTGAGCACGCGGCTTCTCTCACTTTTCTCACGTCAAC CCTGACTCATAACGGAGTTCGGCAGTCCCGGAACGGCTTATAGAAGCAATGCCTGAGTAGATAGCGTCAGGGATCGGCCCTACGTCGAGTCCAGTACGCC ATTGGATGGAGGTCTCAGCCGTCGGTGGAGTGCGGCTCCACCCCCACATGAACGAGGTTGTTCCTGACCACCCCTGAAACTGTGAGAACCATTGTGTCGA AACCAAGAGGCTTGCGTCGCGCTATAGGTCGATTGCCCCCTAGTTTCCCTATATTGAACGTGTTTCCATTAAAGACTCTCGGTAAATCTCACGTATTGCA #### C:\test>junk77 range: 0 .. 199 A:46 C:51 G:47 T:56 range: 1 .. 200 A:46 C:52 G:47 T:55 range: 2 .. 201 A:46 C:53 G:46 T:55 range: 3 .. 202 A:46 C:53 G:46 T:55 range: 4 .. 203 A:47 C:52 G:46 T:55 range: 5 .. 204 A:47 C:52 G:46 T:55 range: 6 .. 205 A:47 C:52 G:46 T:55 range: 7 .. 206 A:47 C:51 G:47 T:55 range: 8 .. 207 A:47 C:51 G:46 T:56 range: 9 .. 208 A:47 C:51 G:46 T:56 range: 10 .. 209 A:47 C:51 G:46 T:56 range: 11 .. 210 A:48 C:50 G:46 T:56 range: 12 .. 211 A:48 C:49 G:46 T:57 range: 13 .. 212 A:47 C:49 G:46 T:58 range: 14 .. 213 A:47 C:49 G:46 T:58 range: 15 .. 214 A:47 C:49 G:45 T:59 range: 16 .. 215 A:46 C:50 G:45 T:59 range: 17 .. 216 A:47 C:50 G:44 T:59 ...