## Beta I FunctionMath Engineering Class

```Public Function BetaI( _
ByVal vA As Variant _
, ByVal vP As Variant _
, ByVal vQ As Variant _
) As Variant```

### Calculate the incomplete Beta function.

Examples:
```    BetaI(0.0, 2, 3) = 0
BetaI(0.1, 2, 3) = 0.0523
BetaI(0.5, 2, 3) = 0.6875
BetaI(0.9, 2, 3) = 0.9963
BetaI(1.0, 2, 3) = 1```
```    Beta Function
BetaLn Function
BetaCDF Function
BetaInverse Function
BetaPDF Function
MathProbability Class
DBETAI Function```
vA: Upper limit of integration. Function returns Null if vA is not between 0 and 1 inclusive, is Null, or cannot be fixed up to a Double precision floating point number.
vP: First beta distribution parameter. Function returns Null if vP is less than or equal to zero (<=0), is Null, or cannot be fixed up to a Double precision floating point number.
vQ: Second beta distribution parameter. Function returns Null if vQ is less than or equal to zero (<=0), is Null, or cannot be fixed up to a Double precision floating point number.

BetaI calculates the Double precision incomplete beta function.
The incomplete beta function ratio is the probability that a random variable from a beta distribution having parameters P and Q will be less than or equal to A.