my $count = $nucleotideDNA =~ tr/ATCG]//c; # Remove and count invalids
Sofie: Note that while this tr/// (see Quote-Like Operators in perlop) expression counts the number of characters that are not ATCG, it does not remove anything; the string is not changed (update: nor is there any need for change):
c:\@Work\Perl\monks>perl -wMstrict -le
"my $DNA = 'ATATCCCGATCAGG3TT!GCA';
;;
my $nucleotideDNA = $DNA;
my $count = $nucleotideDNA =~ tr/ATCG//c;
;;
print $DNA;
print $nucleotideDNA;
;;
print 'sequences are equal' if $DNA eq $nucleotideDNA;
"
ATATCCCGATCAGG3TT!GCA
ATATCCCGATCAGG3TT!GCA
sequences are equal
Also note that there is a ] character in the set | tr/// search set that should not be there.
However, I agree with the main point that BillKSmith is making: string operations with regexes or with operators like substr and index will tend to be significantly faster (update: and to consume significantly less memory) than equivalent array operations.
Give a man a fish: <%-{-{-{-<
-
Are you posting in the right place? Check out Where do I post X? to know for sure.
-
Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
<code> <a> <b> <big>
<blockquote> <br /> <dd>
<dl> <dt> <em> <font>
<h1> <h2> <h3> <h4>
<h5> <h6> <hr /> <i>
<li> <nbsp> <ol> <p>
<small> <strike> <strong>
<sub> <sup> <table>
<td> <th> <tr> <tt>
<u> <ul>
-
Snippets of code should be wrapped in
<code> tags not
<pre> tags. In fact, <pre>
tags should generally be avoided. If they must
be used, extreme care should be
taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
intervention).
-
Want more info? How to link
or How to display code and escape characters
are good places to start.
|