Solves a system of linear equations with a Cholesky-factored symmetric/Hermitian distributed positive-definite matrix.
call pspotrs(uplo, n, nrhs, a, ia, ja, desca, b, ib, jb, descb, info)
call pdpotrs(uplo, n, nrhs, a, ia, ja, desca, b, ib, jb, descb, info)
call pcpotrs(uplo, n, nrhs, a, ia, ja, desca, b, ib, jb, descb, info)
call pzpotrs(uplo, n, nrhs, a, ia, ja, desca, b, ib, jb, descb, info)
The p?potrs routine solves for X a system of distributed linear equations in the form:
sub(A)*X = sub(B) ,
where sub(A) = A(ia:ia+n-1, ja:ja+n-1) is an n-by-n real symmetric or complex Hermitian positive definite distributed matrix, and sub(B) denotes the distributed matrix B(ib:ib+n-1, jb:jb+nrhs-1).
This routine uses Cholesky factorization
sub(A) = UH*U, or sub(A) = L*LH
computed by p?potrf.
(global) CHARACTER*1. Must be 'U' or 'L'.
If uplo = 'U', upper triangle of sub(A) is stored;
If uplo = 'L', lower triangle of sub(A) is stored.
(global) INTEGER. The order of the distributed submatrix sub(A) (n≥0).
(global) INTEGER. The number of right hand sides; the number of columns of the distributed submatrix sub(B) (nrhs≥0).
(local)
REAL for pspotrs
DOUBLE PRECISION for pdpotrs
COMPLEX for pcpotrs
DOUBLE COMPLEX for pzpotrs.
Pointers into the local memory to arrays of local dimension
a(lld_a,LOCc(ja+n-1)) and b(lld_b,LOCc(jb+nrhs-1)), respectively.
The array a contains the factors L or U from the Cholesky factorization sub(A) = L*LH or sub(A) = UH*U, as computed by p?potrf.
On entry, the array b contains the local pieces of the right hand sides sub(B).
(global) INTEGER. The row and column indices in the global array A indicating the first row and the first column of the submatrix sub(A), respectively.
(global and local) INTEGER array, dimension (dlen_). The array descriptor for the distributed matrix A.
(global) INTEGER. The row and column indices in the global array B indicating the first row and the first column of the submatrix sub(B), respectively.
(global and local) INTEGER array, dimension (dlen_). The array descriptor for the distributed matrix B.
Overwritten by the local pieces of the solution matrix X.
INTEGER. If info=0, the execution is successful.
info < 0: if the i-th argument is an array and the j-th entry had an illegal value, then info = -(i*100+j); if the i-th argument is a scalar and had an illegal value, then info = -i.