#include <stdio.h>
#include "neural-nets-ode.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.
*/
void Neural_Net_plot_with_maple(struct Neural_Net_ODE *nn, int n,
		char *outfile)
{
	double a = nn->a;
	double b = nn->b;
	FILE *fp;

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

	fprintf(fp, "plot([");
	for (int i = 0; i <= n; i++) {
		double x = a + (b-a)/n*i;
		Neural_Net_phi(nn, x);
		Neural_Net_eval(nn, x);
		double y = nn->N[0] * nn->phi[0];
		fprintf(fp, "[%g,%g],", x, y);
	}
	fprintf(fp, "NULL], title=\"hidden units = %d, training points = %d",
			nn->q, nn->nu);
	if (nn->exact_sol != NULL)
		fprintf(fp, "\\nerror vs exact = %g",
				Neural_Net_error_vs_exact(nn, n));
	fprintf(fp, "\", color=\"Green\", labels=[x, u(x)], "
			"size=[600,300], font=[Times,bold,14]);\n");
	fclose(fp);
}