Matrix.DetectMtxType Method

Determines type of the matrix.

Pascal

function DetectMtxType(CheckPosDef: boolean = False): TMtxType; overload;

Tests the calling matrix and returns the TMtxType of the calling of matrix. The following types are supported:

mtSymmPosDef = symmetric positive definite matrix
mtSymmetric = symmetric matrix
mtHermPosDef = Hermitian positive definite matrix
mtHermitian = Hermitian matrix
mtTriangle = triangular matrix, with unit or non unit main diagonal
mtGeneral = general matrix (none of the above)

Checking for positive definite matrix can be very expensive (O(n) = 1/3*n^3). Therefore the ChekPosDef parameter is False by default, unless the user specifies otherwise. The method will not detect banded matrix storage.

Example

var X,B: Vector; A: Matrix; at: TMtxType; begin B.SetIt(false,[0,2]); A.SetIt(2,2,false,[1,2, 2,4]); // 2x2 real matrix at := A.DetectMtxType; A.LUSolve(B,X,at); // This is the same for this example (except slower) A.LUSolve(B,X,mtSymmetric); // You could also specify A.AutoMtxType := True A.LUSolve(B,X); // the type is autodetected end;

Matrix Record, Matrix Members, MtxExpr Namespace, public, Example

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