Funções Matemáticas
If you don't have/want GMP and are working with large numbers/currencies:
<?php
function mb_abs($number)
{
return str_replace('-','',$number);
}
?>
No need to worry about encoding, as your numbers should all be basic (ANSI) strings.
abs
(PHP 4, PHP 5)
abs — Valor absoluto
Parâmetros
- number
-
O valor numérico para processar
Valor Retornado
O valor absoluto de number. Se o argumento número é do tipo float, o número retornado também é float, em outro caso será inteiro (mas poderá retornar float se o resultado tiver magnitude maior que inteiro).
Exemplos
Exemplo #1 Exemplo da abs()
<?php
$abs = abs(-4.2); // $abs = 4.2; (double/float)
$abs2 = abs(5); // $abs2 = 5; (inteiro)
$abs3 = abs(-5); // $abs3 = 5; (inteiro)
?>
User Contributed Notes
abs
abs
svein dot tjonndal at gmail dot com
25-May-2011 09:44
25-May-2011 09:44
Ister
16-Jul-2008 10:59
16-Jul-2008 10:59
[*EDIT* by danbrown AT php DOT net: Merged user's corrected code with previous post content.]
jeremys indicated one thing - there is no sgn function wich actually seems a bit strange for me. Of course it is as simple as possible, but it is usefull and it is a standard math function needed occasionally.
Well, I have solved this function in a bit different matter:
<?php
function sgn($liczba)
{
if($liczba>0)
$liczba=1;
else if($liczba<0)
$liczba=-1;
else if(!is_numeric($liczba))
$liczba=null;
else
$liczba=0;
return $liczba;
}
?>
The difference is that it returns null when the argument isn't a number at all.
Josh
07-Jan-2006 02:06
07-Jan-2006 02:06
Let's say you are resizing images to a standard size that can be expressed as a ratio (width/height). The problem I came into was that I wanted to be reasonable with the proportion of the images that my customer is uploading (couldn't we all use a little less horizontal on pictures?), but I wanted to reject the horizontal pictures when they were uploading vertical ones. So I wanted to accept proportions of images that were within a reasonable threshold (+ or -) of what I will be resizing them to.
Assuming a standard of 1 to 4 (0.25) and a threshold of no more than 0.05 deviation, then the number 0.30 and 0.20 would return true and 0.19 would return false.
<?php
function threshold($given,$thresh,$standard)
{
return (abs($given-$standard)<=$thresh) ? true : false;
}
?>