NAG Library Routine Document

f06gwf (zsctr)

1
Purpose

f06gwf (zsctr) scatters the elements of a sparse complex vector x stored in compressed form, into a complex vector y in full storage form.

2
Specification

Fortran Interface
Subroutine f06gwf ( nz, x, indx, y)
Integer, Intent (In):: nz, indx(*)
Complex (Kind=nag_wp), Intent (In):: x(*)
Complex (Kind=nag_wp), Intent (Inout):: y(*)
C Header Interface
#include <nagmk26.h>
void  f06gwf_ (const Integer *nz, const Complex x[], const Integer indx[], Complex y[])
The routine may be called by its BLAS name zsctr.

3
Description

None.

4
References

Dodson D S, Grimes R G and Lewis J G (1991) Sparse extensions to the Fortran basic linear algebra subprograms ACM Trans. Math. Software 17 253–263

5
Arguments

1:     nz – IntegerInput
On entry: the number of nonzeros in the sparse vector x.
2:     x* – Complex (Kind=nag_wp) arrayInput
Note: the dimension of the array x must be at least max1,nz .
On entry: the compressed vector x. x contains xi for iJ.
3:     indx* – Integer arrayInput
Note: the dimension of the array indx must be at least max1,nz .
On entry: the indices of the elements in the compressed vector x.
Constraint: the indices must be distinct.
4:     y* – Complex (Kind=nag_wp) arrayInput/Output
Note: the dimension of the array y must be at least maxkindxk .
On entry: the vector y.
On exit: the vector y, with the elements corresponding to indices in indx altered.

6
Error Indicators and Warnings

None.

7
Accuracy

Not applicable.

8
Parallelism and Performance

f06gwf (zsctr) is not threaded in any implementation.

9
Further Comments

None.

10
Example

None.