create_path_space_filling.c

Example showing how to create space filling curve based path. Benefit of this approach is that results do not have anisotropy in statistical properties (fast and slow axis).

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#include "lib/gwyscan.h"

int
main(void)
{
    int i, order = 4;
    double xreal = 1e-6, yreal = 1e-6;
    /* Create simple space-filling curve of order 4, i.e. filling completely
     * a 16x16 grid. */
    int ndata = gwyscan_create_path_space_filling(NULL, order,
                                                  xreal, yreal, 0.0, 0.0);
    double *xydata = malloc(2*ndata*sizeof(double));
    gwyscan_create_path_space_filling(xydata, order,
                                      xreal, yreal, 0.0, 0.0);

    FILE *fp = fopen("scan_path_space_filling.txt", "wt");
    if (fp == NULL) {
        printf("Error. Unable to open file for writing %s \n", strerror(errno));
        return 0;
    }
    for (i = 0; i < ndata; i++)
        fprintf(fp, "%d %g %g\n", i, xydata[2*i], xydata[2*i + 1]);
    fclose(fp);

    free(xydata);

    return 0;
}