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

136 HP MLIB User’s Guide
SSCTR/DSCTR/ISCTR/CSCTR/ZSCTR Scatter sparse vector
Name SSCTR/DSCTR/ISCTR/CSCTR/ZSCTR
Scatter sparse vector
Purpose Given a real, integer, or complex sparse vector x stored in compact form via a
set of indices, these subprograms scatter those elements into the corresponding
elements of a dense vector y stored in full storage form.
More precisely, let x be a sparse n-vector with m ≤ n interesting (usually
nonzero) elements, and let {k
1
, k
2
, ..., k
m
} be the indices of these elements. If x is
represented by arrays x and indx such that indx(i)=k
i
and x(i)=x
k
i
, then
Usage VECLIB:
INTEGER*4 m, indx(m)
REAL*4 x(m), y(n)
CALL SSCTR(m, x, indx, y)
INTEGER*4 m, indx(m)
REAL*8 x(m), y(n)
CALL DSCTR(m, x, indx, y)
INTEGER*4 m, indx(m), x(m), y(n)
CALL ISCTR(m, x, indx, y)
INTEGER*4 m, indx(m)
COMPLEX*8 x(m), y(n)
CALL CSCTR(m, x, indx, y)
INTEGER*4 m, indx(m)
COMPLEX*16 x(m), y(n)
CALL ZSCTR(m, x, indx, y)
VECLIB8:
INTEGER*8 m, indx(m)
REAL*4 x(m), y(n)
CALL SSCTR(m, x, indx, y)
INTEGER*8 m, indx(m)
REAL*8 x(m), y(n)
CALL DSCTR(m, x, indx, y)
INTEGER*8 m, indx(m), x(m), y(n)
CALL ISCTR(m, x, indx, y)
y
k
i
x
i
= i, 12… m.,, ,=