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AdvancedMathPochhammer Method

Computes the Pochammer symbol (x)y.

Namespace:  Meta.Numerics.Functions
Assembly:  Meta.Numerics (in Meta.Numerics.dll) Version: 4.1.4
public static double Pochhammer(
	double x,
	double y


Type: SystemDouble
The first argument.
Type: SystemDouble
The second argument.

Return Value

Type: Double
The value of (x)y.

The Pochhammer symbol is defined as a ratio of Gamma functions.

For positive integer y, this is equal to a rising factorial product.

Note that while the Pochhammer symbol notation is very common, combinatorialists sometimes use the same notation for a falling factorial.

If you need to compute a ratio of Gamma functions, in most cases you should compute it by calling this function instead of taking the quotient of two calls to the Gamma(Double) function, because there is a large fraction of the parameter space where Gamma(x+y) and Gamma(x) overflow, but their quotient does not, and is correctly computed by this method.

This function accepts both positive and negative values for both x and y.

See Also