Probabilities.ChiSquareCDF Method

Overload List

#SignatureDescription
1procedure ChiSquareCDF(const X: TDenseMtxVec; Nu: Integer; const Res: TDenseMtxVec);Chi-Squared CDF (vectorized).
2function ChiSquareCDF(x: Double; Nu: Integer): Double;Chi-squared cumulative distribution function (CDF).

Overload 1: procedure ChiSquareCDF(const X: TDenseMtxVec; Nu: Integer; const Res: TDenseMtxVec);

Chi-Squared CDF (vectorized).

#NameDescription
1XDefines distribution domain, real vector or matrix with positive values.
2NuDefines distribution degrees of freedom. Nu must be a positive integer value.
3ResAfter calculation stores the CDF calculated from X, m and b. Length and Complex properties of Res are adjusted automatically to match Length and Complex properties of X.

Result: stored in self (calling object)

Overload 2: function ChiSquareCDF(x: Double; Nu: Integer): Double;

Chi-squared cumulative distribution function (CDF).

#NameDescription
1xFunction domain, real value >= 0.
2NuDegrees of freedom, integer > 0.

Returns: Double - the chi-squared cumulative distribution function (CDF) at x with Nu degrees of freedom. Returns NAN when Nu <= 0.

Remarks:

Computes the chi-squared CDF

CDF(x|nu)=integral _0 ^x (t^((nu-2)/2)* exp(-t/2))/(2^(nu/2)*Gamma (nu /2)) dt = P(nu/2,x/2)

i.e. the regularized lower incomplete gamma function; the implementation computes it as GammaCDF(x, Nu/2, 2). The result is the probability that an observation falls in [0,x][0,x], lies in [0,1][0,1] and is monotone non-decreasing. Domain: x >= 0, integer nu > 0. If nu <= 0 the result is NAN.

See Also: Probabilities.ChiSquarePDF, Probabilities.ChiSquareCDFInv