NAG Library Manual, Mark 26
NAG AD Library Manual, Mark 26
NAG C Library Manual, Mark 26
F06 (blas) Chapter Contents
F06 (blas) Chapter Introduction
NAG Library Routine Document
f06fdf (axpzy)
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NAG Library Manual, Mark 26
NAG AD Library Manual, Mark 26
NAG C Library Manual, Mark 26
F06 (blas) Chapter Contents
F06 (blas) Chapter Introduction
▸
▿
Contents
1
Purpose
2
Specification
3
Description
4
References
5
Arguments
6
Error Indicators and Warnings
7
Accuracy
8
Parallelism and Performance
9
Further Comments
10
Example
© The Numerical Algorithms Group Ltd. 2018
1
Purpose
f06fdf
multiplies a real vector by a scalar, preserving the input vector.
2
Specification
Fortran Interface
Subroutine f06fdf (
n
,
alpha
,
x
,
incx
,
y
,
incy
)
Integer, Intent (In)
::
n
,
incx
,
incy
Real (Kind=nag_wp), Intent (In)
::
alpha
,
x(*)
Real (Kind=nag_wp), Intent (Inout)
::
y(*)
C Header Interface
#include <nagmk26.h>
void
f06fdf_ (
const Integer *
n
,
const double *
alpha
,
const double
x
[]
,
const Integer *
incx
,
double
y
[]
,
const Integer *
incy
)
3
Description
f06fdf
performs the operation
y
←
α
x
where
x
and
y
are
n
-element real vectors scattered with stride
incx
and
incy
respectively, and
α
is a real scalar.
4
References
None.
5
Arguments
1:
n
– Integer
Input
On entry
:
n
, the number of elements in
x
and
y
.
2:
alpha
– Real (Kind=nag_wp)
Input
On entry
: the scalar
α
.
3:
x
*
– Real (Kind=nag_wp) array
Input
Note:
the dimension of the array
x
must be at least
max
1
,
1
+
n
-
1
×
incx
.
On entry
: the
n
-element vector
x
.
If
incx
>
0
,
x
i
must be stored in
x
1
+
i
-
1
×
incx
, for
i
=
1
,
2
,
…
,
n
.
If
incx
<
0
,
x
i
must be stored in
x
1
-
n
-
i
×
incx
, for
i
=
1
,
2
,
…
,
n
.
Intermediate elements of
x
are not referenced.
4:
incx
– Integer
Input
On entry
: the increment in the subscripts of
x
between successive elements of
x
.
5:
y
*
– Real (Kind=nag_wp) array
Input/Output
Note:
the dimension of the array
y
must be at least
max
1
,
1
+
n
-
1
×
incy
.
On entry
: if
incy
≠
1
, intermediate elements of
y
may contain values and will not be referenced; the other elements will be overwritten and need not be set.
On exit
: the elements
y
i
of the vector
y
will be stored in
y
as follows.
If
incy
>
0
,
y
i
will be stored in
y
1
+
i
-
1
×
incy
, for
i
=
1
,
2
,
…
,
n
.
If
incy
<
0
,
y
i
will be stored in
y
1
-
n
-
i
×
incy
, for
i
=
1
,
2
,
…
,
n
.
Intermediate elements of
y
are unchanged.
6:
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
Parallelism and Performance
f06fdf
is not threaded in any implementation.
9
Further Comments
None.
10
Example
None.
NAG Library Manual, Mark 26
NAG AD Library Manual, Mark 26
NAG C Library Manual, Mark 26
F06 (blas) Chapter Contents
F06 (blas) Chapter Introduction
© The Numerical Algorithms Group Ltd. 2018