my $dna = 'accatgagctgtacgtagcatctgagcgcgcatgactgtgactgacgtaggcagca';

my $increment = 3;
my @windows;
for ( my $loc=0; $loc <= (length($dna)-10); $loc+=$increment ){
    push @windows, substr($dna, $loc, 10);
}

print "$_\n" for @windows;

[download]

If you have multiple $dna sequences you'll probably want an outer loop to iterate over an array holding them. Otherwise, this code ought to do what you're looking for.

It's one of the few instances where I would actually use a C-style 'for' loop.

You could also do it with a regexp.

Update: Replaced (length($dna)-$increment) with (length($dna)-10) per duff's comment. Good catch!


Dave

In reply to Re: substr help by davido
in thread substr help by Anonymous Monk

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