F06EGF (DSWAP) (PDF version)
F06 Chapter Contents
F06 Chapter Introduction
NAG Library Manual
NAG Library Routine Document
F06EGF (DSWAP)
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
F06EGF (DSWAP) interchanges two
n
element real vectors
x
and
y
.
2 Specification
SUBROUTINE F06EGF (
N
,
X
,
INCX
,
Y
,
INCY
)
INTEGER
N, INCX, INCY
double precision
X(*), Y(*)
The routine may be called by its BLAS name
dswap
.
3 Description
None.
4 References
None.
5 Parameters
1: N – INTEGER
Input
On entry
:
n
, the number of elements in
x
and
y
.
2: X(
*
) –
double precision
array
Input/Output
Note:
the dimension of the array
X
must be at least
max
1
,
1
+
N
-
1
INCX
.
On entry
: the original vector
x
.
On exit
: the original vector
y
.
3: INCX – INTEGER
Input
On entry
: the increment in the subscripts of
X
between successive elements of
x
.
4: Y(
*
) –
double precision
array
Input/Output
Note:
the dimension of the array
Y
must be at least
max
1
,
1
+
N
-
1
INCY
.
On entry
: the original vector
y
.
On exit
: the original vector
x
.
5: INCY – INTEGER
Input
On entry
: the increment in the subscripts of
Y
between successive elements of
y
.
6 Error Indicators and Warnings
None.
7 Accuracy
Not applicable.
8 Further Comments
None.
9 Example
None.
F06EGF (DSWAP) (PDF version)
F06 Chapter Contents
F06 Chapter Introduction
NAG Library Manual
© The Numerical Algorithms Group Ltd, Oxford, UK. 2009