/* maple-plot.c
 *
 * Receives a mesh structure and an array u[] of z values at mesh points.
 * Writes a Maple file that can be used to plot the function u[] over the
 * mesh.
 *
 * Rouben Rostamian <rostamian@umbc.edu>
 * April 2006
 */

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include "maple-plot.h"

void maple_plot(Mesh *mesh, double *u, const char *filename)
{
	FILE *fp;
	size_t n = mesh->nelems;
	size_t i, j;
	time_t now;

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

	time(&now);
	fprintf(fp, "# Maple file created by Math 625 Finite Element Solver\n"
			"# on %s", ctime(&now));
	fprintf(fp, "#\n");
	fprintf(fp, "# View this file in Maple by:\n");
	fprintf(fp, "#     read \"%s\";\n", filename);
	fprintf(fp, "\n");

	fprintf(fp, "with(plottools,polygon):\n");
	fprintf(fp, "plots[display]([\n");

	for (i=0; i<n; i++) {
		fprintf(fp, "polygon([");
		for (j=0; j<3; j++)
			fprintf(fp, "[%g, %g, %g],",
					mesh->elems[i].n[j]->x,
					mesh->elems[i].n[j]->y,
					u[mesh->elems[i].n[j]->nodeno]);
		fprintf(fp, "NULL]),\n");
	}

	fprintf(fp, "NULL], axes=BOXED);\n");

	fclose(fp);
}