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

380 HP MLIB User’s Guide
F_SSBMV/F_DSBMV/F_CSBMV/F_ZSBMV Symmetric band matrix-vector multiply
Y REAL or COMPLEX array, minimum length
(N - 1) x |incy| + 1.
INCY Increment for the array y. A vector y having component
y
i
, i = 1,..., n, is stored in an array Y() with increment
argument incy. If incy > 0 then y
i
is stored in
Y(1 + (i - 1) x incy). If incy < 0 then y
i
is stored in
Y(1 + (N - i) x |incy|). incy = 0 is an illegal value.
Output Y The updated Y vector replaces the input.
y αAx βy with A=A
T
+←