Math387.IGamma Method

Math387

Overload List

#SignatureDescription
1function IGamma(A: Double; const X: TCplx): TCplx;Incomplete gamma function.
2function IGamma(A: Double; X: Double): Double;Incomplete gamma function.

Overload 1: function IGamma(A: Double; const X: TCplx): TCplx;

Incomplete gamma function.

#NameTypeDescription
1ADoublescalar
2XTCplx

Returns: TCplx (complex)

Overload 2: function IGamma(A: Double; X: Double): Double;

Incomplete gamma function.

#NameTypeDescription
1ADoublescalar
2XDoublescalar

Returns: Double - the incomplete gamma function.

Remarks:

The IGamma function is defined by the following equation:

IGamma(x,a)=1Γ(a)∫0xta−1exp⁡(−t)dt\text{IGamma}\left(x,a\right)= \frac{1}{\Gamma(a)} \int _0 ^x t^{a-1} \exp (-t) dt

where Gamma is Math387.Gamma function. Depending on parameters a and x fractional or series expansion is used to calculate the incomplete Gamma function.

See Also: Math387.JGamma, Math387.GammaFrac, Math387.GammaSer, Math387.Gamma