nag_zger (f16smc) (PDF version)
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NAG Library Manual
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NAG Library Function Document
nag_zger (f16smc)
▸
▿
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
10.1
Program Text
10.2
Program Data
10.3
Program Results
1 Purpose
nag_zger (f16smc) performs a rank-1 update on a complex general matrix.
2 Specification
#include <nag.h>
#include <nagf16.h>
void
nag_zger (Nag_OrderType
order
, Nag_ConjType
conj
, Integer
m
, Integer
n
, Complex
alpha
, const Complex
x
[], Integer
incx
, const Complex
y
[], Integer
incy
, Complex
beta
, Complex
a
[], Integer
pda
, NagError *
fail
)
3 Description
nag_zger (f16smc) performs the rank-1 update operation
A
←
α
x
y
T
+
β
A
,
or
A
←
α
x
y
H
+
β
A
,
where
A
is an
m
by
n
complex matrix,
x
is an
m
element complex vector,
y
is an
n
-element complex vector, and
α
and
β
are complex scalars.
4 References
Basic Linear Algebra Subprograms Technical (BLAST) Forum (2001)
Basic Linear Algebra Subprograms Technical (BLAST) Forum Standard
University of Tennessee, Knoxville, Tennessee
http://www.netlib.org/blas/blast-forum/blas-report.pdf
5 Arguments
1:
order
–
Nag_OrderType
Input
On entry
: the
order
argument specifies the two-dimensional storage scheme being used, i.e., row-major ordering or column-major ordering. C language defined storage is specified by
order
=
Nag_RowMajor
. See
Section 2.3.1.3
in How to Use the NAG Library and its Documentation for a more detailed explanation of the use of this argument.
Constraint
:
order
=
Nag_RowMajor
or
Nag_ColMajor
.
2:
conj
–
Nag_ConjType
Input
On entry
: the argument
conj
specifies whether the elements
y
i
are used unconjugated or conjugated, as follows:
conj
=
Nag_NoConj
The elements
y
i
are not conjugated.
conj
=
Nag_Conj
The complex conjugate of the elements
y
i
are used.
Constraint
:
conj
=
Nag_NoConj
or
Nag_Conj
.
3:
m
–
Integer
Input
On entry
:
m
, the number of rows of the matrix
A
.
Constraint
:
m
≥
0
.
4:
n
–
Integer
Input
On entry
:
n
, the number of columns of the matrix
A
.
Constraint
:
n
≥
0
.
5:
alpha
–
Complex
Input
On entry
: the scalar
α
.
6:
x
[
dim
]
–
const Complex
Input
Note:
the dimension,
dim
, 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
[
i
-
1
×
incx
]
, for
i
=
1
,
2
,
…
,
m
.
If
incx
<
0
,
x
i
must be stored in
x
[
m
-
i
×
incx
]
, for
i
=
1
,
2
,
…
,
m
.
Intermediate elements of
x
are not referenced. If
m
=
0
,
x
is not referenced and may be
NULL
.
7:
incx
–
Integer
Input
On entry
: the increment in the subscripts of
x
between successive elements of
x
.
Constraint
:
incx
≠
0
.
8:
y
[
dim
]
–
const Complex
Input
Note:
the dimension,
dim
, of the array
y
must be at least
max
1
,
1
+
n
-
1
incy
.
On entry
: the
n
-element vector
y
.
If
incy
>
0
,
y
i
must be stored in
y
[
i
-
1
×
incy
]
, for
i
=
1
,
2
,
…
,
n
.
If
incy
<
0
,
y
i
must be stored in
y
[
n
-
i
×
incy
]
, for
i
=
1
,
2
,
…
,
n
.
Intermediate elements of
y
are not referenced. If
α
=
0.0
or
n
=
0
,
y
is not referenced and may be
NULL
.
9:
incy
–
Integer
Input
On entry
: the increment in the subscripts of
y
between successive elements of
y
.
Constraint
:
incy
≠
0
.
10:
beta
–
Complex
Input
On entry
: the scalar
β
.
11:
a
[
dim
]
–
Complex
Input/Output
Note:
the dimension,
dim
, of the array
a
must be at least
max
1
,
pda
×
n
when
order
=
Nag_ColMajor
;
max
1
,
m
×
pda
when
order
=
Nag_RowMajor
.
If
order
=
Nag_ColMajor
,
A
i
j
is stored in
a
[
j
-
1
×
pda
+
i
-
1
]
.
If
order
=
Nag_RowMajor
,
A
i
j
is stored in
a
[
i
-
1
×
pda
+
j
-
1
]
.
On entry
: the
m
by
n
matrix
A
.
On exit
: the updated matrix
A
.
12:
pda
–
Integer
Input
On entry
: the stride separating row or column elements (depending on the value of
order
) in the array
a
.
Constraints
:
if
order
=
Nag_ColMajor
,
pda
≥
max
1
,
m
;
if
order
=
Nag_RowMajor
,
pda
≥
n
.
13:
fail
–
NagError *
Input/Output
The NAG error argument (see
Section 2.7
in How to Use the NAG Library and its Documentation).
6 Error Indicators and Warnings
NE_ALLOC_FAIL
Dynamic memory allocation failed.
See
Section 2.3.1.2
in How to Use the NAG Library and its Documentation for further information.
NE_BAD_PARAM
On entry, argument
value
had an illegal value.
NE_INT
On entry,
incx
=
value
.
Constraint:
incx
≠
0
.
On entry,
incy
=
value
.
Constraint:
incy
≠
0
.
On entry,
m
=
value
.
Constraint:
m
≥
0
.
On entry,
n
=
value
.
Constraint:
n
≥
0
.
NE_INT_2
On entry,
pda
=
value
,
m
=
value
.
Constraint:
pda
≥
max
1
,
m
.
On entry,
pda
=
value
and
n
=
value
.
Constraint:
pda
≥
n
.
NE_INTERNAL_ERROR
An internal error has occurred in this function. Check the function call and any array sizes. If the call is correct then please contact
NAG
for assistance.
An unexpected error has been triggered by this function. Please contact
NAG
.
See
Section 2.7.6
in How to Use the NAG Library and its Documentation for further information.
NE_NO_LICENCE
Your licence key may have expired or may not have been installed correctly.
See
Section 2.7.5
in How to Use the NAG Library and its Documentation for further information.
7 Accuracy
The BLAS standard requires accurate implementations which avoid unnecessary over/underflow (see Section 2.7 of
Basic Linear Algebra Subprograms Technical (BLAST) Forum (2001)
).
8 Parallelism and Performance
nag_zger (f16smc) is not threaded in any implementation.
9 Further Comments
None.
10 Example
Perform rank-1 update of complex matrix
A
using vectors
x
and
y
:
A
←
A
-
x
y
H
,
where
A
is the
3
by
2
complex matrix given by
A
=
4.0
+
4.0
i
2.0
+
2.0
i
4.0
+
7.0
i
4.0
+
3.0
i
11.0
+
3.0
i
9.0
+
7.0
i
,
and the vectors
x
and
y
are
x
=
2.0
+
1.0
i
3.0
+
2.0
i
5.0
-
1.0
i
and
y
=
2.0
+
1.0
i
1.0
-
2.0
i
.
The vector
y
is stored in every second element of array
y
(
incy
=
2
).
10.1 Program Text
Program Text (f16smce.c)
10.2 Program Data
Program Data (f16smce.d)
10.3 Program Results
Program Results (f16smce.r)
nag_zger (f16smc) (PDF version)
f16 Chapter Contents
f16 Chapter Introduction
NAG Library Manual
© The Numerical Algorithms Group Ltd, Oxford, UK. 2016