write_options
Sets or retrieves an option for printing a matrix.
Synopsis
#include <imsl.h>
void imsl_write_options (Imsl_write_options option, int *option_value)
Required Arguments
Imsl_write_options option (Input)
Option giving the type of the printing attribute to set or retrieve.
option for Setting | option for Retrieving | Attribute Description |
|---|
IMSL_SET_DEFAULTS | | Use the default settings for all parameters |
IMSL_SET_CENTERING | IMSL_GET_CENTERING | Horizontal centering |
IMSL_SET_ROW_WRAP | IMSL_GET_ROW_WRAP | Row wrapping |
IMSL_SET_PAGING | IMSL_GET_PAGING | Paging |
IMSL_SET_NAN_CHAR | IMSL_GET_NAN_CHAR | Method for printing NaN (not a number) |
IMSL_SET_TITLE_PAGE | IMSL_GET_TITLE_PAGE | Whether or not titles appear on each page |
IMSL_SET_FORMAT | IMSL_GET_FORMAT | Default format for real and complex numbers |
int *option_value (Input, if option is to be set; Output, otherwise)
The value of the option attribute selected by option. The values to be used when setting attributes are described in a table in the description section.
Description
The function
imsl_write_options allows the user to set or retrieve an option for printing a matrix. Options controlled by
imsl_write_options are horizontal centering, method for printing large matrices, paging, method for printing in NaN (not a number), method for printing titles, and the default format for real and complex numbers. (NaN can be retrieved by functions
imsl_f_machine and
imsl_d_machine. For more information, see the description for
imsl_f_machine.
The values that may be used for the attributes are as follows:
Option | Value | Meaning |
|---|
CENTERING | 0 1 | Matrix is left justified. Matrix is centered. |
ROW_WRAP | 0
m | A complete row is printed before the next row is printed. Wrapping is used if necessary. Here m is a positive integer. Let n1 be the maximum number of columns that fit across the page, as determined by the widths in the conversion specifications starting with column 1. First, columns 1 through n1 are printed for rows 1 through m. Let n2 be the maximum number of columns that fit across the page, starting with column
n1 + 1. Second, columns n1+1 through n1 + n2 are printed for rows 1 through m. This continues until the last columns are printed for rows 1 through m. Printing continues in this fashion for the next m rows, etc. |
PAGING | -2 -1
0
k | No paging occurs. Paging is on. Every invocation of a imsl_f_write_matrix function begins on a new page, and paging occurs within each invocation as is needed. Paging is on. The first invocation of a imsl_f_write_matrix function begins on a new page, and subsequent paging occurs as is needed. Paging occurs in the second and all subsequent calls to a imsl_f_write_matrix function only as needed. Turn paging on and set the number of lines printed on the current page to k lines. If k is greater than or equal to the page length, then the first invocation of a imsl_f_write_matrix function begins on a new page. In any case, subsequent paging occurs as is needed. |
NAN_CHAR | 0 1 | . . . . . . . . . . is printed for NaN. A blank field is printed for NaN. |
TITLE_PAGE | 0 1 | Title appears only on first page. Title appears on the first page and all continuation pages. |
FORMAT | 0 1 2 | Format is "%10.4x". Format is "%12.6w". Format is "%22.5e". |
The w conversion character used by the FORMAT option is a special conversion character that can be used to automatically select a pretty C conversion specification ending in either e, f, or d. The conversion specification ending with w is specified as "%n.dw". Here, n is the field width, and d is the number of significant digits generally printed.
The function
imsl_write_options can be invoked repeatedly before using a
write_matrix function to print a matrix. The matrix printing functions retrieve the values set by
imsl_write_options to determine the printing options. It is not necessary to call
imsl_write_options if a default value of a printing option is desired. The defaults are as follows:
Option | Default Value | Description |
|---|
CENTERING | 0 | Left justified |
ROW_WRAP | 1000 | Lines before wrapping |
PAGING | -2 | No paging |
NAN_CHAR | 0 | . . . . . . . . . . . . . . |
TITLE_PAGE | 0 | Title appears only on the first page |
FORMAT | 0 | %10.4w |
Example
The following example illustrates the effect of imsl_write_options when printing a 3 × 4 real matrix A with IMSL function imsl_f_write_matrix, where aij = i + j∕10. The first call to imsl_write_options sets horizontal centering so that the matrix is printed centered horizontally on the page. In the next invocation of imsl_f_write_matrix, the left-justification option has been set via function imsl_write_options, so the matrix is left justified when printed.
#include <imsl.h>
#define NRA 4
#define NCA 3
int main()
{
int i, j, option_value;
float a[NRA][NCA];
for (i = 0; i < NRA; i++) {
for (j = 0; j < NCA; j++) {
a[i][j] = (i+1) + (j+1)/10.0;
}
}
/* Activate centering option */
option_value = 1;
imsl_write_options (IMSL_SET_CENTERING, &option_value);
/* Write a matrix */
imsl_f_write_matrix ("a", NRA, NCA, (float*) a, 0);
/* Activate left justification */
option_value = 0;
imsl_write_options (IMSL_SET_CENTERING, &option_value);
imsl_f_write_matrix ("a", NRA, NCA, (float*) a, 0);
}
Output
a
1 2 3
1 1.1 1.2 1.3
2 2.1 2.2 2.3
3 3.1 3.2 3.3
4 4.1 4.2 4.3
a
1 2 3
1 1.1 1.2 1.3
2 2.1 2.2 2.3
3 3.1 3.2 3.3
4 4.1 4.2 4.3
