Developer Reference for Intel® oneAPI Math Kernel Library for C
p?trsm
Solves a distributed matrix equation (one matrix operand is triangular).
Syntax
void pstrsm(const char *side, const char *uplo, const char *transa, const char *diag,
const MKL_INT *m, const MKL_INT *n, const float *alpha, const float *a,
const MKL_INT *ia, const MKL_INT *ja, const MKL_INT *desca, float *b,
const MKL_INT *ib, const MKL_INT *jb, const MKL_INT *descb);
void pdtrsm(const char *side, const char *uplo, const char *transa, const char *diag,
const MKL_INT *m, const MKL_INT *n, const double *alpha, const double *a,
const MKL_INT *ia, const MKL_INT *ja, const MKL_INT *desca, double *b,
const MKL_INT *ib, const MKL_INT *jb, const MKL_INT *descb);
void pctrsm(const char *side, const char *uplo, const char *transa, const char *diag,
const MKL_INT *m, const MKL_INT *n, const MKL_Complex8 *alpha,
const MKL_Complex8 *a, const MKL_INT *ia, const MKL_INT *ja,
const MKL_INT *desca, MKL_Complex8 *b, const MKL_INT *ib, const MKL_INT *jb,
const MKL_INT *descb);
void pztrsm(const char *side, const char *uplo, const char *transa, const char *diag,
const MKL_INT *m, const MKL_INT *n, const MKL_Complex16 *alpha,
const MKL_Complex16 *a, const MKL_INT *ia, const MKL_INT *ja,
const MKL_INT *desca, MKL_Complex16 *b, const MKL_INT *ib, const MKL_INT *jb,
const MKL_INT *descb);Include Files
mkl_pblas.h
Description
The p?trsm routines solve one of the following distributed matrix equations: op(sub( A ))* X = alpha *sub( B ),
or X *op(sub( A )) = alpha *sub( B ),
where:
alpha is a scalar,
X and sub(B) are m -by- n distributed matrices, sub(B)=B(ib:ib+m-1, jb:jb+n-1) ;
A is a unit, or non-unit, upper or lower triangular distributed matrix, sub(A)=A(ia:ia+m-1, ja:ja+m-1) , if side = 'L' or 'l' , and sub(A)=A(ia:ia+n-1, ja:ja+n-1) , if side = 'R' or 'r' ;
op(sub(A)) is one of op(sub(A)) = sub(A) , or op(sub(A)) = sub(A)' , or op(sub(A)) = conjg(sub(A)') .
The distributed matrix sub(B) is overwritten by the solution matrix X .
Input Parameters
side
(global) Specifies whether op(sub(A)) appears on the left or right of X in the equation:
if side = 'L' or ‘l’ , then op(sub(A))*X = alpha*sub(B) ; if side = 'R' or ‘r’ , then X*op(sub(A)) = alpha*sub(B) .
uplo
(global) Specifies whether the distributed matrix sub(A) is upper or lower triangular:
if uplo = 'U' or ‘u’ , then the matrix is upper triangular; if uplo = 'L' or ‘l’ , then the matrix is low triangular.
transa
(global) Specifies the form of op(sub(A)) used in the matrix equation:
if transa = 'N' or 'n' , then op(sub(A)) = sub(A) ; if transa = 'T' or 't' , then op(sub(A)) = sub(A)' ; if transa = 'C' or 'c' , then op(sub(A)) = conjg(sub(A)') .
diag
(global) Specifies whether the matrix sub(A) is unit triangular:
if diag = 'U' or ‘u’ then the matrix is unit triangular; if diag = 'N' or ‘n’ , then the matrix is not unit triangular.
m
(global) Specifies the number of rows of the distributed matrix sub(B) , m ≥ 0.
n
(global) Specifies the number of columns of the distributed matrix sub(B) , n ≥ 0.
alpha
(global)
DOUBLE PRECISION for pdtrsm COMPLEX for pctrsm DOUBLE COMPLEX for pztrsm Specifies the scalar alpha . When alpha is zero, then a is not referenced and b need not be set before entry.
a
(local)
DOUBLE PRECISION for pdtrsm COMPLEX for pctrsm DOUBLE COMPLEX for pztrsm Array, size lld_a by ka , where ka is at least LOCq(1, ja+m-1) when side = 'L' or ‘l’ and is at least LOCq(1, ja+n-1) when side = 'R' or ‘r’ . Before entry with uplo = 'U' or ‘u’ , this array contains the local entries corresponding to the entries of the upper triangular distributed matrix sub(A) , and the local entries corresponding to the entries of the strictly lower triangular part of the distributed matrix sub(A) is not referenced. Before entry with uplo = 'L' or ‘l’ , this array contains the local entries corresponding to the entries of the lower triangular distributed matrix sub(A) , and the local entries corresponding to the entries of the strictly upper triangular part of the distributed matrix sub(A) is not referenced . When diag = 'U' or ‘u’ , the local entries corresponding to the diagonal elements of the submatrix sub(A) are not referenced either, but are assumed to be unity.
ia , ja
(global) The row and column indices in the distributed matrix A indicating the first row and the first column of the submatrix sub(A) , respectively.
desca
(global and local) array of dimension 9. The array descriptor of the distributed matrix A .
b
(local)
DOUBLE PRECISION for pdtrsm COMPLEX for pctrsm DOUBLE COMPLEX for pztrsm Array, size ( lld_b , LOCq(1, jb+n-1) ). Before entry, this array contains the local pieces of the distributed matrix sub(B) .
ib , jb
(global) The row and column indices in the distributed matrix B indicating the first row and the first column of the submatrix sub(B) , respectively.
descb
(global and local) array of dimension 9. The array descriptor of the distributed matrix B .
Output Parameters
- b
-
Overwritten by the solution distributed matrix X .