Re: FW: [PATCH] Bug #24064: Standard deviation
| From: | Andrey Hristov | Date: | Tue, 10 Feb 2004 08:15:06 +0000 |
| Subject: | Re: FW: [PATCH] Bug #24064: Standard deviation | ||
| References: | 1 | Groups: | php.internals |
| Request: | Send a blank email to internals+get-7686@lists.php.net to get a copy of this message | ||
Hi,
as Derick stated 2 days ago, the problem is not in the extension but in the
MIME header. The attachment must be text/plain.
Andrey
Quoting Paul Hudson <webjedi@hudzilla.eclipse.co.uk>:
> Er, either the php-internals MARC archive doesn't show all attachments, or
> my diff file got stripped en route for not having a .txt extension. I've
> attached it again, just to make sure.
>
>
> Paul
> --
>
> -----Original Message-----
> From: Paul Hudson [mailto:webjedi@hudzilla.eclipse.co.uk]
> Sent: 10 February 2004 00:30
> To: 'internals@lists.php.net'
> Subject: [PATCH] Bug #24064: Standard deviation
>
> Hi there,
>
> Bug #24064 (submitted by tularis@php.net) requests a standard deviation
> function for PHP. I realise that any of you could implement this in 10
> minutes, but according to the bug database it is still Open so I figured I
> would give it a try myself!
>
> There are probably a dozen errors in the code and/or places where it could
> be better optimised, but I'm hoping one of you might be able to help with
> that. So, the attached diff file implements the function array_std_dev(),
> to calculate standard deviation using the deviation method.
>
> With the function in place, standard deviation is calculated like this:
>
> <?php
> $scores = array(18,5,7,18,3,2,10);
> print array_std_dev($score);
> // prints 6.6833125519211
> ?>
>
> My first attempt at implementing this was using an extra array to buffer the
> deviations - this was more out of curiosity to see how the array stuff
> works. Sadly, it caused PHP to segfault and I couldn't figure out why - can
> any of you help me spot the brain fart? (I've attached the offending code
> in bad_stddev_code.txt)
>
> Yours,
>
>
> Paul
>
> PS: I'm not on the internals list, so I would appreciate it if you would CC
> me on your reply.
>