stats_cdf_t

(PECL stats >= 1.0.0)

stats_cdf_t — Calculates any one parameter of the T distribution given values for the others.

Description

float stats_cdf_t ( float $par1 , float $par2 , int $which )

Warning

This function is currently not documented; only its argument list is available.

Parameters

par1
par2
which

Return Values

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Brian ¶

2 years ago


In order to match the output of this function with Excel's TDIST function, you must take 1 - the value.  For example, for a two-tailed T-distribution for x=4 and degrees of freedom=2, the formula would be:



(1 - stats_cdf_t(4, 2, 1)) * 2



For a single tail, do not include the multiply by 2 portion.

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Anonymous ¶

1 year ago


Input  and return values of stats_cdf_t depends on the $which-parameter:

<?php

function get_t_p($t, $df){

  return stats_cdf_t($t, $df, 1);

}

function get_t_t($p, $df){

  return stats_cdf_t($p, $df, 2);

}

function get_t_df($p, $t){

  return stats_cdf_t($p, $t, 3);

}

?>

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