10**( log(1/(1-rand()))/log(2) ) - 1

[download]

[Update: You may want to shorten the range if you get too many small (0.x) values or values that are too large. Replace 1-rand() with, for example .9-.8*rand().] 

10**( -log(1-rand())/log(2) ) - 1 # (same thing)
(1-rand())**(log(.1)/log(2)) - 1  # (same thing)

[download]

- tye        

I'd show the (interesting) derivation, except the more words I include in a reply to you, the more likely the whole thing will turn ugly.

In reply to Re: Rand() with ?log10? distribution? (math) by tye
in thread Rand() with ?log10? distribution? by BrowserUk

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.