create_path_octave_profiles.c

Example showing how to create a one-dimensional octave scan. Octave scan is used to get optimum information for roughness spectral properties evaluation, here only from fast scanning axis.

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

#include "lib/gwyscan.h"

int
main(void)
{
    int i, order = 4, noctaves = 5, nprof = 50;
    double xreal = 1e-6, yreal = 1e-6;
    /* Create spiral centered at the origin. */
    int ndata = gwyscan_create_path_octave_profiles(NULL,
                                                    order, noctaves, nprof,
                                                    xreal, yreal, 0.0, 0.0);
    double *xydata = malloc(2*ndata*sizeof(double));
    gwyscan_create_path_octave_profiles(xydata, order, noctaves, nprof,
                                        xreal, yreal, 0.0, 0.0);

    FILE *fp = fopen("scan_path_octave_profiles.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;
}