#! /usr/bin/perl $data_file="optmimierung_test.txt"; open(DAT, $data_file) || die("Died"); @raw_data=; close(DAT); $tmp; foreach $line (@raw_data) { ($n,$file,$angle)=split(/\t/,$line); if ($n != 1) { $new_angle=$tmp - $angle; $new_angle %= 360; $line =~ s/$angle/$new_angle\n/; } else { $new_angle = $angle; } $tmp = $new_angle; $angle = $new_angle; print $line; }