NAG CPP Interface
nagcpp::blas::dlange (f06ra)

1 Purpose

dlange returns the value of the 1-norm, the -norm, the Frobenius norm, or the maximum absolute value of the elements of a real m by n matrix.

2 Specification

#include "f06/nagcpp_f06ra.hpp"
template <typename A>

double dlange(const string norm, const A &a, OptionalF06RA opt)
template <typename A>

double dlange(const string norm, const A &a)

3 Description

None.

4 References

None.

5 Arguments

1: norm string Input
On entry: specifies the value to be returned.
norm='1' or 'O'
The 1-norm.
norm='I'
The -norm.
norm='F' or 'E'
The Frobenius (or Euclidean) norm.
norm='M'
The value maxi,j|aij| (not a norm).
Constraint: norm='1', 'O', 'I', 'F', 'E' or 'M'.
2: a(m,n) double array Input
On entry: the m by n matrix A.
3: opt OptionalF06RA Input/Output
Optional parameter container, derived from Optional.

5.1Additional Quantities

1: m
m, the number of rows of the matrix A
2: n
n, the number of columns of the matrix A

6 Exceptions and Warnings

All errors and warnings have an associated numeric error code field, errorid, stored either as a member of the thrown exception object (see errorid), or as a member of opt.ifail, depending on how errors and warnings are being handled (see Error Handling for more details).
Raises: ErrorException
errorid=1
On entry, error in parameter norm.
Constraint: norm = "1","O","I","F","E"​ or ​"M".
errorid=2
On entry, error in parameter m.
Constraint: m0.
errorid=3
On entry, error in parameter n.
Constraint: n0.
errorid=10601
On entry, argument value must be a value x value array.
Supplied argument has value dimensions.
errorid=10601
On entry, argument value must be a value x value array.
Supplied argument was a value x value array.
errorid=10601
On entry, argument value must be a value x value array.
Not all of the sizes for the supplied array could be ascertained.
errorid=10602
On entry, the raw data component of value is null.
errorid=10603
On entry, unable to ascertain a value for value.
errorid=10604
On entry, the data in value is stored in value Major Order.
The data was expected to be in value Major Order.
errorid=-99
An unexpected error has been triggered by this routine.
errorid=-999
Dynamic memory allocation failed.

7 Accuracy

Not applicable.

8 Parallelism and Performance

Please see the description for the underlying computational routine in this section of the FL Interface documentation.

9 Further Comments

None.

10 Example

Examples of the use of this method may be found in the examples for: real_​nmf_​rcomm.