I defined the median back in my May 6<\/a> post. It’s preferred over the mean in some realms; I’ll explore the reason another time.<\/p>\n Today, we’ll look at a Perl program that finds the median. It’s a great way to jump-start the Perl-programming discussion, as well as show off a couple of Perl’s built-in functions. Here it is:<\/p>\n Notice the %<\/span> on line 9. It’s the modulus operator, and gives the remainder of a division. If you divide by 2 and get a remainder of 0, the number must be even.<\/p>\n This program will serve as a platform from which to launch discussions in future posts. Stay tuned:)<\/p>\n Sources:<\/p>\n McGrath, Mike. Perl in easy steps<\/em>. Warwickshire: Computer Step, 2004.<\/p>\n Robert’s Perl Tutorial<\/a><\/p>\n
\n#!\/usr\/bin\/perl
\n
\n@lst=sort{$a <=> $b}@ARGV;
\n#uses Perl’s built-in sort to write the numbers, in ascending order, #into @lst<\/span>
\n$n=0;
\nforeach(@ARGV){
\n$n++;
\n} #this loop counts the numbers given to the program<\/span>
\nif($n%2==0){#if the list has an even number of values<\/span>
\n$num1=$lst[$n\/2-1];
\n#arrays start at 0, so you need to adjust down one place when #referencing.<\/span>
\n$num2=$lst[$n\/2];
\n$med=($num1+$num2)\/2;
\n}
\nelse{ #the list has an odd number of values<\/span>
\n$med=$lst[($n-1)\/2];
\n}
\nprint “The list you entered is\\n\\n”;
\nforeach $one(@ARGV){
\nprint “$one “;
\n}
\nprint “\\n\\n”; #makes space for reading<\/span>
\nprint “The list in ascending order is\\n\\n”;
\nforeach $one(@lst){
\nprint “$one “;
\n}
\nprint “\\n\\n”;
\nprint “The median is $med :)”;
\nprint “\\n\\n”;<\/p>\n