NAG CL Interface
x04dec (print_​matrix_​complex_​band)

Settings help

CL Name Style:

1 Purpose

x04dec is an easy-to-use function to print a Complex band matrix.

2 Specification

#include <nag.h>
void  x04dec (Nag_OrderType order, Integer m, Integer n, Integer kl, Integer ku, const Complex a[], Integer pda, const char *title, const char *outfile, NagError *fail)
The function may be called by the names: x04dec, nag_file_print_matrix_complex_band or nag_band_complx_mat_print.

3 Description

x04dec prints a Complex band matrix stored in packed form. It is an easy-to-use driver for x04dfc. The function uses default values for the format in which numbers are printed, for labelling the rows and columns, and for output record length.
x04dec will choose a format code such that numbers will be printed with a %8.4f, a %11.4f or a %13.4e format. The %8.4f code is chosen if the sizes of all the matrix elements to be printed lie between 0.001 and 1.0. The %11.4f code is chosen if the sizes of all the matrix elements to be printed lie between 0.001 and 9999.9999. Otherwise the %13.4e code is chosen. The chosen code is used to print each complex element of the matrix with the real part above the imaginary part.
The matrix is printed with integer row and column labels, and with a maximum record length of 80.
The matrix is output to the file specified by outfile or, by default, to standard output.

4 References


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 3.1.3 in the Introduction to the NAG Library CL Interface for a more detailed explanation of the use of this argument.
Constraint: order=Nag_RowMajor or Nag_ColMajor.
2: m Integer Input
3: n Integer Input
On entry: the number of rows and columns of the band matrix, respectively, to be printed.
If either m or n is less than 1, x04dec will exit immediately after printing title; no row or column labels are printed.
4: kl Integer Input
On entry: the number of subdiagonals of the band matrix A.
Constraint: kl0.
5: ku Integer Input
On entry: the number of superdiagonals of the band matrix A.
Constraint: ku0.
6: a[dim] const Complex Input
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.
On entry: the band matrix to be printed.
This is stored as a notional two-dimensional array with row elements or column elements stored contiguously. The storage of elements Aij, for row i=1,,m and column j=max(1,i-kl),,min(n,i+ku), depends on the order argument as follows:
  • if order=Nag_ColMajor, Aij is stored as a[(j-1)×pda+ku+i-j];
  • if order=Nag_RowMajor, Aij is stored as a[(i-1)×pda+kl+j-i].
7: pda Integer Input
On entry: the stride separating row or column elements (depending on the value of order) of the matrix A in the array a.
Constraint: pdakl+ku+1.
8: title const char * Input
On entry: a title to be printed above the matrix.
If title=NULL, no title (and no blank line) will be printed.
If title contains more than 80 characters, the contents of title will be wrapped onto more than one line, with the break after 80 characters.
Any trailing blank characters in title are ignored.
9: outfile const char * Input
On entry: the name of a file to which output will be directed. If outfile is NULL the output will be directed to standard output.
10: fail NagError * Input/Output
The NAG error argument (see Section 7 in the Introduction to the NAG Library CL Interface).

6 Error Indicators and Warnings

Memory allocation failed.
On entry, argument value had an illegal value.
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.
Cannot open file value for appending.
Cannot close file value.
Cannot open file value for writing.

7 Accuracy

Not applicable.

8 Parallelism and Performance

Background information to multithreading can be found in the Multithreading documentation.
x04dec is not threaded in any implementation.

9 Further Comments

A call to x04dec is equivalent to a call to x04dfc with the following argument values:

10 Example