Sparky2mars.pl, create MARS pseudoresidue table from Sparky assignment table

From NMR Wiki

Purpose

Create MARS assignment table input from sparky list of chemical shifts.

Usage

in sparky "assign" peaks to arbitrarily named pseudoresidues, e.g. P1, P2, etc.
use atom names CA CA-1 CB CB-1 CO CO-1 HN N.
save assignment table
create file sparky2mars.pl with the content shown in "code" section below.
run:

sparky2mars.pl <   sparky.shifts   >  mars_shifts.inp

Code

#!/usr/bin/perl
 
use strict;
 
my @lines = <>;
 
shift  @lines;
shift  @lines;
 
my %at;
foreach my $l (@lines) {
    chomp $l;
    my @bits = split ' ', $l;
    my $resname = $bits[0];
    my $atom = $bits[1];
    my $shift = $bits[3];
    my $count = $bits[5];
    next if $count == 0;
    $at{$resname}{$atom} = $shift;
}
 
my @atom_list = qw (CA    CA-1      CB    CB-1      CO    CO-1       HN       N);
 
print "\t", join("\t",@atom_list), "\n";
 
for my $resname (keys %at) {
    my $rec = $at{$resname};
    print $resname, "\t";
 
    for my $catom (@atom_list) {
        if (exists $rec->{$catom}) {
            print $rec->{$catom};
        }
        else {
            print '-';
        }
        print "\t";
    }
    print "\n";
 
}