However, when include this code in the entire script, only the first 3 out of 4 files are processed. Is there a reason for this behaviour?

No. It's not the code. I see four possibilities:

After 

my @files = <substituent_R*.txt>;

[download]
add 
use Data::Dumper;
$Data::Dumper::Useqq = 1;
warn(Dumper(\@files));

[download]

Do you see the four files? Are there any weird characters?

If you didn't answered yes and no, post the output and continue.

After 

my $avg = $sum / $cnt;

[download]
add 
warn("Average=$avg\n");

[download]

Do you see four averages? Are any of them very near 1?

If you didn't answered yes and no, post the output and continue.

After every line, add 

warn(__LINE__, " for $fn_in\n");

[download]

Post your output.

In reply to Re^5: Batch processing of files by ikegami
in thread Batch processing of files by austinby

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.