HP MLIB User's Guide Vol. 1 7th Ed.

Chapter 3 Basic Matrix Operations 331
Solve triangular systems STRSM/DTRSM/CTRSM/ZTRSM
Example 1 Form the REAL*4 matrix solution A
−1
B, where A is a 6-by-6 nonunit-diagonal,
upper-triangular real matrix stored in an array A whose dimensions are
10-by-10 and B is a 6-by-8 real matrix stored in an array B of dimension
10-by-10. The matrix solution overwrites the input B matrix.
CHARACTER*1 SIDE,UPLO,TRANSA,DIAG
INTEGER*4 M,N,LDA,LDB
REAL*4 ALPHA,A(10,10),B(10,10)
SIDE = ’L’
UPLO = ’U’
TRANSA = ’N’
DIAG = ’N’
M = 6
N = 8
ALPHA = 1.0
LDA = 10
LDB = 10
CALL STRSM (SIDE,UPLO,TRANSA,DIAG,M,N,ALPHA,A,LDA,B,LDB)
Example 2 Form the REAL*8 matrix solution qBA
−T
, where q is a real scalar, B is a 6-by-8
real matrix stored in an array B of dimension 10-by-10, and A is a 8-by-8
unit-diagonal lower-triangular real matrix stored in an array A whose
dimensions are 10-by-10. The matrix solution overwrites the input B matrix.
INTEGER*4 M,N,LDA,LDB
REAL*8 Q,A(10,10),B(10,10)
M = 6
N = 8
LDA = 10
LDB = 10
CALL DTRSM (’RIGHT’,’LOWER’,’TRANS’,’UNIT’,M,N,Q,A,LDA,B,LDB)