I tried to alert the OP to this issue in my post:

Sorry. I missed that.

your tr/// method missed reversing the string afterwards, but that won't change the fact that the tr/// approach is the way to go.

Right on both counts. And it make's more of a difference than I was expecting, but still 80x faster than the next best:

    tr => q[
        ( my $revcmp = reverse $seq ) =~ tr[ACGTacgt][tgcaTGCA];
    ],

C:\test>junk60
             Rate     hdb atcroft  davido      tr
hdb        9827/s      --    -36%    -71%   -100%
atcroft   15292/s     56%      --    -55%    -99%
davido    33822/s    244%    121%      --    -99%
tr      2640400/s  26770%  17167%   7707%      --

[download]
With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.

In reply to Re^3: Create the reverse complement DNA sequence without pattern matching and reverse built-in function? by BrowserUk
in thread Create the reverse complement DNA sequence without pattern matching and reverse built-in function? by Anonymous Monk

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.