PHP 7.2.0 Release Candidate 4 Released

# stats_cdf_t

(PECL stats >= 1.0.0)

stats_cdf_tCalculates any one parameter of the t-distribution given values for the others.

### Description

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

Returns the cumulative distribution function, its inverse, or one of its parameters, of the t-distribution. The kind of the return value and parameters (`par1` and `par2`) are determined by `which`.

The following table lists the return value and parameters by `which`. CDF, x, and nu denotes cumurative distribution function, the value of the random variable, and the degrees of freedom of the t-distribution, respectively.

Return value and parameters
`which` Return value `par1` `par2`
1 CDF x nu
2 x CDF nu
3 nu x CDF

### Parameters

`par1`

The first parameter

`par2`

The second parameter

`which`

The flag to determine what to be calculated

### Return Values

Returns CDF, x, or nu, determined by `which`.

``` 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)) * 2For a single tail, do not include the multiply by 2 portion. ```
``` Input  and return values of stats_cdf_t depends on the \$which-parameter:<?phpfunction 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);}?> ```