# stats_cdf_beta

(PECL stats >= 1.0.0)

stats_cdf_betaCalculates any one parameter of the beta distribution given values for the others

### Descrição

stats_cdf_beta ( float `\$par1` , float `\$par2` , float `\$par3` , int `\$which` ) : float

Returns the cumulative distribution function, its inverse, or one of its parameters, of the beta 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, alpha, and beta denotes cumulative distribution function, the value of the random variable, and shape parameters of the beta distribution, respectively.

Return value and parameters
`which` Return value `par1` `par2` `par3`
1 CDF x alpha beta
2 x CDF alpha beta
3 alpha x CDF beta
4 beta x CDF alpha

### Parâmetros

`par1`

The first parameter

`par2`

The second parameter

`par3`

The third parameter

`which`

The flag to determine what to be calculated

Returns CDF, x, alpha, or beta, determined by `which`. add a note

### User Contributed Notes 2 notes

Anonymous
13 years ago
``` Additional Notes, taken from source. WHICH --> Integer indicating which of the next four argument       values is to be calculated from the others.     Legal range: 1..4     iwhich = 1 : Calculate P and Q from X,Y,A and B     iwhich = 2 : Calculate X and Y from P,Q,A and B     iwhich = 3 : Calculate A from P,Q,X,Y and B     iwhich = 4 : Calculate B from P,Q,X,Y and A          P <--> The integral from 0 to X of the chi-square     distribution.     Input range: [0, 1].          Q <--> 1-P.     Input range: [0, 1].     P + Q = 1.0.          X <--> Upper limit of integration of beta density.     Input range: [0,1].     Search range: [0,1]          Y <--> 1-X.     Input range: [0,1].     Search range: [0,1]     X + Y = 1.0.          A <--> The first parameter of the beta density.     Input range: (0, +infinity).     Search range: [1D-100,1D100]          B <--> The second parameter of the beta density.     Input range: (0, +infinity).     Search range: [1D-100,1D100] ```
-1
n15m0_jk
6 years ago
``` Decided to dive into the source code and provide a simple explanation:Parameters:int \$which - Select which parameter to use in the CDF Binomial calculation, based on what the prior 3 parameters are.where \$which is 4:\$arg1 = p\$arg2 = sn\$arg3 = xnreturns pr\$which = 3\$arg1 = p\$arg2 = sn\$arg3 = prreturns xn\$which = 2\$arg1 = p\$arg2 = xn\$arg3 = prreturns sn\$which = 1\$arg1 = sn\$arg2 = xn\$arg3 = prreturns p ``` 