NAG CL Interface
x04ccc (print_​matrix_​real_​packed)

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1 Purpose

x04ccc is an easy-to-use function to print a double triangular matrix stored in a packed one-dimensional array.

2 Specification

#include <nag.h>
void  x04ccc (Nag_OrderType order, Nag_UploType uplo, Nag_DiagType diag, Integer n, const double a[], const char *title, const char *outfile, NagError *fail)
The function may be called by the names: x04ccc, nag_file_print_matrix_real_packed or nag_pack_real_mat_print.

3 Description

x04ccc prints a double triangular matrix stored in packed form. It is an easy-to-use driver for x04cdc. The function uses default values for the format in which numbers are printed, for labelling the rows and columns, and for output record length.
x04ccc 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 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

None.

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: uplo Nag_UploType Input
On entry: indicates the type of the matrix to be printed
uplo=Nag_Lower
The matrix is lower triangular
uplo=Nag_Upper
The matrix is upper triangular
Constraint: uplo=Nag_Lower or Nag_Upper.
3: diag Nag_DiagType Input
On entry: indicates whether the diagonal elements of the matrix are to be printed.
diag=Nag_NonRefDiag
The diagonal elements of the matrix are not referenced and not printed.
diag=Nag_UnitDiag
The diagonal elements of the matrix are not referenced, but are assumed all to be unity, and are printed as such.
diag=Nag_NonUnitDiag
The diagonal elements of the matrix are referenced and printed.
Constraint: diag=Nag_NonRefDiag, Nag_UnitDiag or Nag_NonUnitDiag.
4: n Integer Input
On entry: the order of the matrix to be printed.
If n is less than 1, x04ccc will exit immediately after printing title; no row or column labels are printed.
5: a[dim] const double Input
Note: the dimension, dim, of the array a must be at least max(1,n×(n+1)/2).
On entry: the matrix to be printed. Note that a must have space for the diagonal elements of the matrix, even if these are not stored.
The storage of elements Aij depends on the order and uplo arguments as follows:
if order=Nag_ColMajor and uplo=Nag_Upper,
Aij is stored in a[(j-1)×j/2+i-1], for ij;
if order=Nag_ColMajor and uplo=Nag_Lower,
Aij is stored in a[(2n-j)×(j-1)/2+i-1], for ij;
if order=Nag_RowMajor and uplo=Nag_Upper,
Aij is stored in a[(2n-i)×(i-1)/2+j-1], for ij;
if order=Nag_RowMajor and uplo=Nag_Lower,
Aij is stored in a[(i-1)×i/2+j-1], for ij.
If diag=Nag_UnitDiag, the diagonal elements of A are assumed to be 1, and are not referenced; the same storage scheme is used whether diag=Nag_NonUnitDiag or diag=Nag_UnitDiag.
6: 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.
7: 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.
8: 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

NE_ALLOC_FAIL
Memory allocation failed.
NE_BAD_PARAM
On entry, argument value had an illegal value.
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.
NE_NOT_APPEND_FILE
Cannot open file value for appending.
NE_NOT_CLOSE_FILE
Cannot close file value.
NE_NOT_WRITE_FILE
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.
x04ccc is not threaded in any implementation.

9 Further Comments

A call to x04ccc is equivalent to a call to x04cdc with the following argument values:

10 Example

See g02btc.