# stats_cdf_t

(PECL stats >= 1.0.0)

stats_cdf_t — Calculates any one parameter of the t-distribution given values for the others

### 说明

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

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

### 参数

`par1`

  The first parameter

`par2`

  The second parameter

`which`

  The flag to determine what to be calculated

### 返回值

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