#include <stdio.h>
#include "neural-nets-pde.h"

/* Writes a Maple script to plot the solution sampled at n+1 equally
 * spaced points x[0] = a, x[1], x[2], ..., x[n] on the interval [a,b].
 * The distance between a pair consecutive points is (b-a)/n.
 *
 * If the script is named file.mpl, then execute it in Maple by
 * entering the command
 *      read "/path/to/file.mpl";
 *
 * Alternatively, copy and paste the contents of file.mpl into
 * a Maple worksheet.  This latter option makes it possible to
 * edit the plotting command before executing it.
*/

// We are in the domain if  phi > -EPS.
#define EPS	1e-12

void Neural_Net_plot_with_maple(struct Neural_Net_PDE *nn, int n, int m,
		char *outfile)
{
	double a = nn->bb_xrange[0];
	double b = nn->bb_xrange[1];
	double c = nn->bb_yrange[0];
	double d = nn->bb_yrange[1];
	FILE *fp;

	if ((fp = fopen(outfile, "w")) == NULL) {
		fprintf(stderr, "unable to open file `%s' for writing\n",
				outfile);
		return;
	}

	fprintf(fp, "plots:-display(MESH([");

	for (int i = 0; i <= m; i++) {
		double y = c + (d-c)/m*i;
		fprintf(fp, "[");
		for (int j = 0; j <= m; j++) {
			double x = a + (b-a)/n*j;
			nn->phi_func(nn, x, y);
			if (nn->phi[0][0] > -EPS) {
				Neural_Net_eval(nn, x, y);
				double z = nn->phi[0][0]*nn->N[0][0];
				fprintf(fp, "[%g,%g,%g],", x, y, z);
			} else {
				fprintf(fp, "[%g,%g,undefined],", x, y);
			}
		}
		fprintf(fp, "NULL],");
	}
	fprintf(fp, "NULL]), labels=[x,y,z]);\n");

	fclose(fp);
}