PHP Manual: Calculates any one parameter of the non-central chi-square distribution given values for the others

Description

float stats_cdf_noncentral_chisquare(
    float $par1,
    float $par2,
    float $par3,
    int $which
)

Returns the cumulative distribution function, its inverse, or one of its parameters, of the non-central chi-square distribution. The kind of the return value and parameters (par1, par2, and par3) are determined by which.

The following table lists the return value and parameters by which. CDF, x, k, and lambda denotes cumulative distribution function, the value of the random variable, the degree of freedom and the non-centrality parameter of the distribution, respectively.

**Return value and parameters**
`which`	Return value	`par1`	`par2`	`par3`
1	CDF	x	k	lambda
2	x	CDF	k	lambda
3	k	x	CDF	lambda
4	lambda	x	CDF	k

Parameters

par1: The first parameter
par2: The second parameter
par3: The third parameter
which: The flag to determine what to be calculated

Return Values

Returns CDF, x, k, or lambda, determined by which.