Computes the Cholesky factorization of a symmetric/Hermitian positive definite matrix (local unblocked algorithm).
routinecomputes the Cholesky factorization of a real symmetric or complex Hermitian positive definite distributed matrix sub
The factorization has the form
'U', or sub(
Uis an upper triangular matrix,
Lis lower triangular.
X'denotes transpose (conjugate transpose) of
- (global)CHARACTER.Specifies whether the upper or lower triangular part of the symmetric/Hermitian matrixAis stored.='U': upper triangle of sub (A) is stored;='L': lower triangle of sub (A) is stored.
- (global)INTEGER.The number of rows and columns to be operated on, that is, the order of the distributed matrix sub (A)..n≥0
- (local)REALforpspotf2DOUBLE PRECISIONforpdpotf2COMPLEXforpcpotf2COMPLEX*16forpzpotf2.Pointer into the local memory to an array of sizecontaining the local pieces of the(lld_a,LOCc(ja+n-1))n-by-nsymmetric distributed matrix sub(A) to be factored.If, the leadinguplo='U'n-by-nupper triangular part of sub(A) contains the upper triangular matrix and the strictly lower triangular part of this matrix is not referenced.If, the leadinguplo='L'n-by-nlower triangular part of sub(A) contains the lower triangular matrix and the strictly upper triangular part of sub(A) is not referenced.
- (global)INTEGER.The row and column indices in the global matrixAindicating the first row and the first column of the sub(A), respectively.
- (global and local)array of sizeINTEGERdlen_. The array descriptor for the distributed matrixA.
- (local)On exit,if, the upper triangular part of the distributed matrix contains the Cholesky factoruplo='U'U;if, the lower triangular part of the distributed matrix contains the Cholesky factoruplo='L'L.
- (local)INTEGER.= 0: successful exit< 0: if thei-th argument is an array and thej-th entry had an illegal value,theninfo= - (i*100 +j),if thei-th argument is a scalar and had an illegal value,theninfo= -i.: if>0info=k, the leading minor of orderkis not positive definite, and the factorization could not be completed.