SPRSAX function takes a row-indexed
sparse array created by the SPRSIN function and multiplies it by an
-element vector to its right. The result is a
SPRSAX is based on the routine
described in section 2.7 of
Numerical Recipes in C: The Art of Scientific Computing
(Second Edition), published by Cambridge University Press, and is used by permission.
Result = SPRSAX(
A row-indexed sparse array created by the SPRSIN function.
-element right hand vector.
Set this keyword to force the computation to be done in double-precision arithmetic.
Begin by creating an array A:
A = [[ 5.0, 0.0, 0.0], $
[ 3.0, -2.0, 0.0], $
[ 4.0, -1.0, 0.0]]
X = [1.0, 2.0, -1.0]
result = SPRSAX(SPRSIN(A),X)
5.00000 -1.00000 2.00000