The most significant error (shift as a sub) has been already mentioned. (Put a large 'S' as the first char if you need to name it that way).

I'd like to make a comment to other aspects of your code. If you give a reference to something into a sub, this (referenced) object will be modified, so you won't need to copy it back and forth.

 ...
 # the array will be modified 'in place', so theres
 # no necessity to copy stuff around
 Shift( \@reduced_protein, $x2-$x1, $y2-$y1, $z2-$z1 ); 
 
 ...

 sub Shift
{
 my ($rp_ref, $x, $y, $z) = @_;   # traditional way to  feed a sub
 my $index1;                      
 # the expression @$array_ref expands a reference to a list
 my $protein_length = findColumnLength(@$rp_ref);
 for (shifting operation) {
    ...
    # instead of:   $reduced_protein[i], 
    # you say:      $rp_ref->[i]
    ...
 }
 # no need to return anything, the original array is
 # already modified
}

[download]

Regards

mwa

In reply to Re: Passing Lists to Functions? by mwah
in thread Passing Lists to Functions? by Anonymous Monk

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.