Computes the product U*U' or L'*L, where U and L are upper or lower triangular matrices.
call pslauum(uplo, n, a, ia, ja, desca)
call pdlauum(uplo, n, a, ia, ja, desca)
call pclauum(uplo, n, a, ia, ja, desca)
call pzlauum(uplo, n, a, ia, ja, desca)
The p?lauum routine computes the product U*U' or L'*L, where the triangular factor U or L is stored in the upper or lower triangular part of the matrix sub(A)= A(ia:ia+n-1, ja:ja+n-1).
If uplo = 'U' or 'u', then the upper triangle of the result is stored, overwriting the factor U in sub(A). If uplo = 'L' or 'l', then the lower triangle of the result is stored, overwriting the factor L in sub(A).
This is the blocked form of the algorithm, calling Level 3 PBLAS.
(global) CHARACTER*1.
Specifies whether the triangular factor stored in the matrix sub(A) is upper or lower triangular:
= 'U': upper triangular
= 'L': lower triangular.
(global) INTEGER.
The number of rows and columns to be operated on, that is, the order of the triangular factor U or L. n ≥ 0.
(local)
REAL for pslauum
DOUBLE PRECISION for pdlauum
COMPLEX for pclauum
COMPLEX*16 for pzlauum.
Pointer into the local memory to an array of DIMENSION(lld_a, LOCc(ja+n-1). On entry, the local pieces of the triangular factor U or L.
(global) INTEGER.
The row index in the global array A indicating the first row of sub(A).
(global) INTEGER.
The column index in the global array A indicating the first column of sub(A).
(global and local) INTEGER array of DIMENSION (dlen_). The array descriptor for the distributed matrix A.
(local)
On exit, if uplo = 'U', the upper triangle of the distributed matrix sub(A) is overwritten with the upper triangle of the product U*U' ; if uplo = 'L', the lower triangle of sub(A) is overwritten with the lower triangle of the product L'*L.