The problem turns out to be that the string in the plot file used double quotes around the data file name, like:
    plot "E:\tmp\xxxx\data" title ""

When I tried that directly in gnuplot, the complaint was: 
    warning: Skipping unreadable file "E:tmpxxxxdata"
    No data in plot

[download]
For Windows, it appears that single quotes are needed to allow the single slash character \ to go through. I changed the line around 1381 from:
    $string = "\"$fileTmp\"";
to
    $string = "'$fileTmp'";

The previous issue of the temp files existing was me not realizing that they all get destroyed on exit, I had to insert a "sleep 30" command in the module after the plot was executed so I could see what the plot and data files looked like before they were removed. Gnuplot errors were not printed to the DOS window.

In reply to Re: Chart::Gnuplot dataset under Windows XP empty GIF by anthonyt
in thread Chart::Gnuplot dataset under Windows XP empty GIF by anthonyt

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.