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

314 HP MLIB User’s Guide
STPSV/DTPSV/CTPSV/ZTPSV Solve triangular system
Lower triangular matrix
If A is
then A is packed column by column into an array ap as follows:
Lower-triangular matrix element a
ij
is stored in array element
ap(i+((j−1)×(2n−j))/2).
Usage VECLIB:
CHARACTER*1 uplo, trans, diag
INTEGER*4 n, incx
REAL*4 ap(lenap), x(lenx)
CALL STPSV(uplo, trans, diag, n, ap, x, incx)
CHARACTER*1 uplo, trans, diag
INTEGER*4 n, incx
REAL*8 ap(lenap), x(lenx)
CALL DTPSV(uplo, trans, diag, n, ap, x, incx)
CHARACTER*1 uplo, trans, diag
INTEGER*4 n, incx
COMPLEX*8 ap(lenap), x(lenx)
CALL CTPSV(uplo, trans, diag, n, ap, x, incx)
CHARACTER*1 uplo, trans, diag
INTEGER*4 n, incx
COMPLEX*16 ap(lenap), x(lenx)
CALL ZTPSV(uplo, trans, diag, n, ap, x, incx)
VECLIB8:
CHARACTER*1 uplo, trans, diag
INTEGER*8 n, incx
REAL*4 ap(lenap), x(lenx)
CALL STPSV(uplo, trans, diag, n, ap, x, incx)
11 0 0 0
21 22 0 0
31 32 33 0
41 42 43 44
k 12345678910
ap(k) 11213141223242334344