Re: Calculating statistical median

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Re^2: Calculating statistical median by revdiablo (Prior) on Jul 13, 2005 at 17:08 UTC
The original post pretty clearly states that he wants the median. Why you posted a snippet that calculates the mean is beyond me. update: Maybe the original post was updated at some point without notice?	[reply]
Re^2: Calculating statistical median by jimbojones (Friar) on Jul 13, 2005 at 15:35 UTC
Hi. Is there a special reason for the array reference? Versus this? `sub mean { my $result; foreach (@_) { $result += $_ } return $result / @_; } my @points = qw(1 2 3 4); print mean @points;` [download]	[reply] [d/l]
Re^3: Calculating statistical median by dirac (Beadle) on Jul 14, 2005 at 07:07 UTC
Copying an array or hash into @_ takes time. Passing arrays and hashes by reference is straightforward. See Benchmark If you want median: `sub median { $_[0]->[ @{$_[0]} / 2 ] } my @points = 0..100; print median(\@points), "\n";` [download]	[reply] [d/l]
Re^4: Calculating statistical median by Anonymous Monk on Apr 22, 2016 at 13:59 UTC
It should sort the array before calculating median this way. Besides that it does not handle the array with even elements correctly.	[reply]
Re^4: Calculating statistical median by Anonymous Monk on May 02, 2016 at 14:04 UTC
This calculates median only if @points is already truly ordered.	[reply]
Re^4: Calculating statistical median by Anonymous Monk on Jun 16, 2017 at 09:49 UTC
This sample has a bug: if input array is not sorted, the result is incorrect. `$ cat median.pl sub median { $_[0]->[ @{$_[0]} / 2 ] } my @sample=(9, 1, 2, 3, 4, 8, 7, 6, 5); my @sorted; @sorted=sort @sample; print median(\@sample),"\n"; print median(\@sorted),"\n"; $ perl median.pl 4 5 $` [download] Should be `5 5` [download]	[reply] [d/l] [select]
Re^4: Calculating statistical median by jimbojones (Friar) on Jul 14, 2005 at 13:51 UTC
Hi Thanks. Didn't know about the speed issue. - j	[reply]