Solved

Counting diagraphs and trigraphs in Perl

Posted on 2004-08-21
2
444 Views
Last Modified: 2010-07-27
Hi,
   I have a string in perl say    "hh bbb. rt irr"

   I'm looking for some way of going through that string and counting how many three letter words there are and how many two letter words. punctuation should be ignored....


 Any takers? :)


0
Comment
Question by:petepalmer
2 Comments
 
LVL 10

Expert Comment

by:rj2
ID: 11859203
$text="hh bbb. rt irr";
@words = split(/[\s.,;:\'\"\\\/\`\~\!\@\#\$\%\^\& \*\(\)\_\- \+\+\[\]\{\}\?]+/,$text);
foreach(@words) {      
      $twocharwords++ if length($_)==2;
      $threecharwords++ if length($_)==3;
}
print "two char word count: $twocharwords, three char word count: $threecharwords\n";
0
 
LVL 20

Accepted Solution

by:
jmcg earned 250 total points
ID: 11859824
(spelling error in title corrected)

Actually, the words digraph and trigraph are usually used with a different meaning: they refer to two-character and three-character sequences regardless of whether they appear as independent words or as part of larger words. The statistics of digraphs and trigraphs can be used in compression algorithms and in code breaking.

If we take from your question that you want to count the number of two- and three-character sequences (sequences, that is, containing alphabetic characters only), the approach that rj2 has shown is pretty good. If I were doing it, I'd probably do it more like:

my @words = $text =~ m{\b([a-zA-Z]+)\b}g;
my @histogram;
$histogram[length]++ foreach @words;
print "length\tcount\n";
printf "%5d\t%5d\n" $_, $histogram[$_] foreach (2..3);

or, change that last line to get the entire histogram,

printf "%5d\t%5d\n" $_, $histogram[$_] foreach (1 .. $#histogram);

0

Featured Post

Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

There are many situations when we need to display the data in sorted order. For example: Student details by name or by rank or by total marks etc. If you are working on data driven based projects then you will use sorting techniques very frequently.…
Checking the Alert Log in AWS RDS Oracle can be a pain through their user interface.  I made a script to download the Alert Log, look for errors, and email me the trace files.  In this article I'll describe what I did and share my script.
Explain concepts important to validation of email addresses with regular expressions. Applies to most languages/tools that uses regular expressions. Consider email address RFCs: Look at HTML5 form input element (with type=email) regex pattern: T…

856 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question