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justindmartin/Sigmoid Function.php

Last active February 8, 2019 18:07
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This is a sigmoid function in PHP.
Raw
Sigmoid Function.php
<?php
function sigmoid($t){
return 1 / (1 + pow(M_EULER, -$t));
}
?>
@mickrip
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mickrip commented Jun 27, 2013 •
edited

I happened to google this looking to use a signoid curve. I found yours didn't work, but this did.

<?php
function sigmoid($t){
    return 1 / (1 + exp(-$t));
}
?>

@digitalgrease
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The problem with it is M_EULER should be M_E.

@raymondjplante
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Both work (with M_E, that is). Anyone happen to have softmax PHP function handy?

@raymondjplante
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Wrote a basic softmax in case anyone's interested: https://gist.github.com/raymondjplante/d826df05349c1d4350e0aa2d7ca01da4

@ai-a
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ai-a commented Feb 8, 2019

Thanks a million! was looking for this function! so simple!

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