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

Chapter 3 Basic Matrix Operations 261
Rank-2 update SSPR2/DSPR2/CHPR2/ZHPR2
Usage VECLIB:
CHARACTER*1 uplo
INTEGER*4 n, incx, incy
REAL*4 alpha, ap(lenap), x(lenx), y(leny)
CALL SSPR2(uplo, n, alpha, x, incx, y, incy, ap)
CHARACTER*1 uplo
INTEGER*4 n, incx, incy
REAL*8 alpha, ap(lenap), x(lenx), y(leny)
CALL DSPR2(uplo, n, alpha, x, incx, y, incy, ap)
CHARACTER*1 uplo
INTEGER*4 n, incx, incy
COMPLEX*8 alpha, ap(lenap), x(lenx), y(leny)
CALL CHPR2(uplo, n, alpha, x, incx, y, incy, ap)
CHARACTER*1 uplo
INTEGER*4 n, incx, incy
COMPLEX*16 alpha, ap(lenap), x(lenx), y(leny)
CALL ZHPR2(uplo, n, alpha, x, incx, y, incy, ap)
VECLIB8:
CHARACTER*1 uplo
INTEGER*8 n, incx, incy
REAL*4 alpha, ap(lenap), x(lenx), y(leny)
CALL SSPR2(uplo, n, alpha, x, incx, y, incy, ap)
CHARACTER*1 uplo
INTEGER*8 n, incx, incy
REAL*8 alpha, ap(lenap), x(lenx), y(leny)
CALL DSPR2(uplo, n, alpha, x, incx, y, incy, ap)
CHARACTER*1 uplo
INTEGER*8 n, incx, incy
COMPLEX*8 alpha, ap(lenap), x(lenx), y(leny)
CALL CHPR2(uplo, n, alpha, x, incx, y, incy, ap)
CHARACTER*1 uplo
INTEGER*8 n, incx, incy
COMPLEX*16 alpha, ap(lenap), x(lenx), y(leny)
CALL ZHPR2(uplo, n, alpha, x, incx, y, incy, ap)
Input uplo Upper/lower triangular option for A: