F06GWF (ZSCTR) (PDF version)
F06 Chapter Contents
F06 Chapter Introduction
NAG Library Manual
NAG Library Routine Document
F06GWF (ZSCTR)
Note:
before using this routine, please read the Users' Note for your implementation to check the interpretation of
bold italicised
terms and other implementation-dependent details.
+
−
Contents
1
Purpose
2
Specification
3
Description
4
References
5
Parameters
6
Error Indicators and Warnings
7
Accuracy
8
Further Comments
9
Example
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
SUBROUTINE F06GWF (
NZ
,
X
,
INDX
,
Y
)
INTEGER
NZ, INDX(*)
COMPLEX (KIND=nag_wp)
X(*), 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 Parameters
1: NZ – INTEGER
Input
On entry
: the number of nonzeros in the sparse vector
x
.
2: X(
*
) – COMPLEX (KIND=nag_wp) array
Input
Note:
the dimension of the array
X
must be at least
max
1
,
NZ
.
On entry
: the compressed vector
x
.
X
contains
x
i
for
i
∈
J
.
3: INDX(
*
) – INTEGER array
Input
Note:
the dimension of the array
INDX
must be at least
max
1
,
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) array
Output
Note:
the dimension of the array
Y
must be at least
max
k
INDX
k
.
On exit
: the vector
y
. Only elements corresponding to indices in
INDX
are altered.
6 Error Indicators and Warnings
None.
7 Accuracy
Not applicable.
8 Further Comments
None.
9 Example
None.
F06GWF (ZSCTR) (PDF version)
F06 Chapter Contents
F06 Chapter Introduction
NAG Library Manual
© The Numerical Algorithms Group Ltd, Oxford, UK. 2012