Evaluates the inverse of the Gamma cumulative probability
distribution function.
Namespace: Imsl.StatAssembly: ImslCS (in ImslCS.dll) Version: 6.5.2.0
Syntax public static double Gamma(
double p,
double a
)
Public Shared Function Gamma (
p As Double,
a As Double
) As Double
public:
static double Gamma(
double p,
double a
)
static member Gamma :
p : float *
a : float -> float
Parameters
- p
- Type: SystemDouble
A double scalar value representing the probability at which
the function is to be evaluated.
- a
- Type: SystemDouble
A double scalar value representing the shape parameter. This
must be positive.
Return Value
Type:
Double
A
double scalar value. The probability that a Gamma random
variable takes a value less than or equal to this returned value is
p.
Remarks
Method
InvCdf.Gamma evaluates the inverse distribution function of
a Gamma random variable with shape parameter
a,
that is, it determines
,
such that
where
is the Gamma function. The
probability that the random variable takes a value less than or
equal to
x is
P. See the
Cdf.Gamma
remarks for further discussion of the
Gamma
distribution.
InvCdf.Gamma uses bisection and modified regula falsi to
invert the distribution function, which is evaluated using method
Cdf.Gamma.
See Also