Hi
my first hints:
a) use 'use strict;' to protect yourself. Yes, this advice is annoying but helpful.
b) The script gives warnings on runtime: Follow them.
c) The line for ($j = 1; $j <= 20;$j++) is IMHO wrong as a perl array is accessed with index starting with 0, so for ($j = 0; $j < 20;$j++).
d) Why do you use an external program to generate random numbers? See perldoc -f rand.
e) Don't initialize the random numer generator before every rand().
f) Your code to instantiate the %nuc-hash is in a way that you get an array of strings. Afterwards you convert them implicitly to float numbers. So instantiate them acordingly. 
%nuc = (
'F' => [0.001, 0.001, ...],
...
)

[download]
g) Instead of programming this "ugly" if-elsif-else-statement at the end use a mapping-hash. It's better readable, it's better maintainable and it's less error prone. 
my %mapping = (
    1 => "A",
    2 => "R",
    3 => "N",
    ...
);
if(exists $mapping{$names[$j]}) {
    $names[$j] = $mapping{$names[$j]};
}
else {
    # Default value (last else-Statement)
    $names[$j]="V";
}

[download]

In reply to Re: string mutation script behaving erraticaly by McA
in thread string mutation script behaving erraticaly by zing

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.