... I just want to the number of the first column to minus the second column.

Note that the OPed statement
    $a=$tmp1[1]-$tmp1[0];
yields the result of the second column minus the first column. (Actually, it gives you the result of the second array element minus the first and we're assuming these elements are input data columns, but that's another question.)

Update: It just occurred to me that the OPed question might be properly paraphrased as "I want the number of the first column to be subtracted from the second column"; in that case, disregard the reply above.

Give a man a fish:  <%-{-{-{-<

In reply to Re: wrong in minus by AnomalousMonk
in thread wrong in minus by yueli711

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.