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

116 HP MLIB User’s Guide
SROT/DROT/CROT/CSROT/ZROT/ZDROT Apply Givens rotation
incx < 0 x is stored backward in array x; that
is, x
i
is stored in x((i−n)×incx+1).
Use incx = 1 if the vector x is stored contiguously in
array x; that is, if x
i
is stored in x(i). Refer to “BLAS
Indexing Conventions” in the introduction to this
chapter.
y Array of length leny = (n−1)×|incy|+1 containing the
n-vector y.
incy Increment for the array y, incy ≠ 0:
incy > 0 y is stored forward in array y; that is,
y
i
is stored in y((i−1)×incy+1).
incy < 0 y is stored backward in array y; that
is, y
i
is stored in y((i−n)×incy+1).
Use incy = 1 if the vector y is stored contiguously in
array y; that is, if y
i
is stored in y(i). Refer to “BLAS
Indexing Conventions” in the introduction to this
chapter.
c The scalar c.
s The scalar s.
Output x and y If n ≤ 0 or if c = 1 and s = 0, then x and y are
unchanged. Otherwise, the result vectors overwrite the
input.