nag_pack_real_mat_print (x04ccc) (PDF version)
x04 Chapter Contents
x04 Chapter Introduction
NAG C Library Manual

NAG Library Function Document

nag_pack_real_mat_print (x04ccc)

+ Contents

    1  Purpose
    7  Accuracy
    9  Example

1  Purpose

nag_pack_real_mat_print (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>
#include <nagx04.h>
void  nag_pack_real_mat_print (Nag_OrderType order, Nag_UploType uplo, Nag_DiagType diag, Integer n, const double a[], const char *title, const char *outfile, NagError *fail)

3  Description

nag_pack_real_mat_print (x04ccc) prints a double triangular matrix stored in packed form. It is an easy-to-use driver for nag_pack_real_mat_print_comp (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.
nag_pack_real_mat_print (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:     orderNag_OrderTypeInput
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 3.2.1.3 in the Essential Introduction for a more detailed explanation of the use of this argument.
Constraint: order=Nag_RowMajor or Nag_ColMajor.
2:     uploNag_UploTypeInput
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:     diagNag_DiagTypeInput
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:     nIntegerInput
On entry: the order of the matrix to be printed.
If n is less than 1, nag_pack_real_mat_print (x04ccc) will exit immediately after printing title; no row or column labels are printed.
5:     a[dim]const doubleInput
Note: the dimension, dim, of the array a must be at least max1,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:     titleconst 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:     outfileconst 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:     failNagError *Input/Output
The NAG error argument (see Section 3.6 in the Essential Introduction).

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  Further Comments

A call to nag_pack_real_mat_print (x04ccc) is equivalent to a call to nag_pack_real_mat_print_comp (x04cdc) with the following argument values:

ncols = 80
indent = 0
labrow = Nag_IntegerLabels
labcol = Nag_IntegerLabels
form = 0

9  Example

See Section 9 in nag_sum_sqs_update (g02btc).

nag_pack_real_mat_print (x04ccc) (PDF version)
x04 Chapter Contents
x04 Chapter Introduction
NAG C Library Manual

© The Numerical Algorithms Group Ltd, Oxford, UK. 2012