File:Demipenteract graph ortho.svg

static int nbit( int x ) {
	int n = 0;
	while(x) { if(x&1) ++n; x >>= 1; }
	return n;
}

void main() {
	const int D  = 5; const int NV = 16; const int NE = 80;
	double v[NV][D]; int    e[NE][2];
	double px[NV]; double py[NV];
		// Magic numbers
	const double x1 = -.1464466094; const double y1 =  .3535533906;
	const double x2 = -.1464466094; const double y2 = -.3535533906;
        const double x3 = -.3535533906; const double y3 =  .1464466094;
	const double y4 = -.1464466094; const double x4 = -.3535533906;
	const double x5 = 0;            const double y5 = 0;
	const double PX[D] = {x1,x2,x3,x4,x5};
	const double PY[D] = {y1,y2,y3,y4,y5};
	int i,j,k,l;

	for(k=0,i=0;i<(1<<D);++i) if(nbit(i)%2==0){
		for(j=0;j<D;++j) v[k][j] = (i>>j)&1 ? 1.0 : -1.0;
		++k;
	}
	assert(k==NV);

	for(k=0,i=0;i<NV-1;++i) for(j=i+1;j<NV;++j) {
		double d = 0;
		for(l=0;l<D;++l) { double t = v[i][l]-v[j][l]; d += t*t; }
		if(d==8) { e[k][0]=i; e[k][1]=j; ++k; }
	}
	
	for(i=0;i<NV;++i){
		px[i] = 0; for(l=0;l<D;++l) px[i] += v[i][l]*PX[l];
		py[i] = 0; for(l=0;l<D;++l) py[i] += v[i][l]*PY[l];
	}
	
	const double SX = 800; const double SY = 800;
	const double B  = 64;  const double R  = 12;
	
	const double sca  = std::min((SX-2*B)/2,(SY-2*B)/2);
	for(i=0;i<NV;++i) { px[i] = B+(px[i]+1)*sca; py[i] = B+(py[i]+1)*sca; }

	FILE * fp = fopen("c:\\temp\\Demipenteract_Graph2.svg","w");
	fprintf(fp,
		"<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\"?>\n"
		"<svg\n"
		"xmlns:svg=\"http://www.w3.org/2000/svg\"\n"
		"xmlns=\"http://www.w3.org/2000/svg\"\n"
		"version=\"1.0\"\n"
		"width=\"%g\"\n" "height=\"%g\"\n"
		"id=\"Demipenteract_Graph2\">\n"
		,SX,SY
	);

	fprintf(fp,"<g style=\"stroke:#000000;stroke-width:3;stroke-opacity:1.0;\">\n");
	for(i=0;i<NE;++i)
		fprintf(fp,
			"<line x1=\"%5.1lf\" y1=\"%5.1lf\" x2=\"%5.1lf\" y2=\"%5.1lf\"/>\n"
			,px[e[i][0]],py[e[i][0]], px[e[i][1]],py[e[i][1]]
		);
	fprintf(fp,"</g>\n");

	fprintf(fp,"<g style=\"stroke:#000000;stroke-width:2;fill:#0000E0\">\n");
	for(i=0;i<NV;++i)
		fprintf(fp,"<circle cx=\"%5.1lf\" cy=\"%5.1lf\" r=\"%5.1lf\"/>\n",px[i],py[i],R);
	fprintf(fp,"</g>\n");

	fprintf(fp,"</svg>\n");
	fclose(fp);
}