Tag: Programming

Calculating average using a perl script

Shavin Fonseka3 Comments

Ok here is the basic perl script for calculating average.

I assume you know how to run the script if you dont ( I will put up a tutorial later so for now dig around in other forms )

Perl Script for calculating average from another file

#!/usr/bin/perl
#calculate averate from a file

use strict;

my $total = 0;
my $count =0;
while (my $line = <>) {
      $total +=$line;
      $count ++=;
}
print "Average = ", $total / $count, "\n";

So the  explaniation for the above code is…

use strict; – allow to find simple mistakes

to find the $average need to calculate

my $total

and the total number of lines

my $count

At the begining of the loop these values are 0.

therefore define the inital value

my $total  = 0;
my $count =0;

So now what you need to do this read each line andadd each value consequtively.

while (my $line = <>) {
   $total += $line;
   $count ++=;
 }
print "Average = ", $total / $count, "\n";

Read the first line.  Then add then and the value read to the total inital value  of 0.

   $total = $line + $total

calculate the total

   $count = $count + 1

calculate the total number of lines read
this can be written in short form as below

   $total += $line;
   $count ++=;

then go back in loop adding value conseutively until there are no more lines to read and then print the line

print "Average = ", $total / $count, "\n";

Hope this is clear I will put a anotated diagram up with more explanation later on.

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