int *generateNCounts(galaxy *gals, int numGals, int numVoxelsPerDim, int xStart,
int yStart, int zStart, int boxLength){
// Allocate the voxel array.
int *voxels = calloc(pow(numVoxelsPerDim, 3), sizeof(int));
// Convert the galaxy list to cartesian coordinates.
cartesianGalaxy *cartGals = convertToCartesian(gals, numGals);
// Loop through each galaxy and add it to the corresponding voxel.
double voxelLength = (double)boxLength/numVoxelsPerDim;
int ind;
#pragma omp parallel for
for(ind = 0; ind < numGals; ind++){
// Adjust the location of the galaxy.
double x = (cartGals+ind)->x - xStart;
double y = (cartGals+ind)->y - yStart;
double z = (cartGals+ind)->z - zStart;
// Calculate the index of the galaxy.
int i = x/voxelLength;
int j = y/voxelLength;
int k = z/voxelLength;
int index = i + numVoxelsPerDim*j + pow(numVoxelsPerDim, 2)*k;
// Increment the voxel at this location.
#pragma omp critical
voxels[index]++;
}
return voxels;
}
/**
* Compute the area as a diagnostic and print it stdout.
*/
void SwarmCylinders::Spline::computeArea()
{
double da = 1e-3;
vector<double> x;
vector<double> y;
for (int i = 0; i < 1.0 / da; i++)
{
vector<double> a;
a.push_back(i * da * M_PI);
vector<double> r;
r.push_back(evaluate(a[0]));
convertToCartesian(r, a);
x.push_back(r[0]);
y.push_back(a[0]);
a.clear();
r.clear();
}
double area = 0;
const int xsize = x.size();
for (int i = 0; i < xsize - 1; i++)
area += 0.5 * (x[i + 1] - x[i]) * (y[i] + y[i + 1]);
printf("** Area: %1.10f", -area);
}
/**
* Check if the spline crosses the y-axis, if so, abort.
*/
void SwarmCylinders::checkValidityOfSpline() const
{
const int nSpline = 512;
const double ymin = 0.10; // if 0, prevents you from creating splines that cross the y-axis
const double dalpha = 2.0 * M_PI / (double) nSpline;
vector<double> xTest;
vector<double> yTest;
for (int i = 0; i < nSpline; i++)
{
xTest.push_back(spline.evaluate((double) i + 0.5) * dalpha);
yTest.push_back(((double) i + 0.5) * dalpha);
}
convertToCartesian(xTest, yTest);
for (int i = 0; i < nSpline; i++)
{
if (yTest[i] < ymin)
{
printf("** The spline crosses or is too close to the the mirror plane! (ymin = %0.4f, k1 = %0.4f k2 = %0.4f, alpha = %0.4f)\n", ymin, K1, K2, alpha);
abort();
}
}
}
QImage CurveTransform::transform() {
for(unsigned int i = 0; i < image_width; i++) {
for(unsigned int j = 0; j < image_height; j++) {
CartesianPair coords = {i, j};
drawPixels(convertToPixels(convertToCartesian(convertToPolar(coords))),coords); //Lisp, eat your heart out
}
}
return out_image;
}
/**
* Initially place the cylinders somewhere inside the region bounded by the
* spline.
*/
void SwarmCylinders::placeCylinders()
{
printf("** Number of agents: %d\n", n);
printf("** Placing agents %1.4f inside of the boundary! \n", rmin);
double dalpha = 2.0 * M_PI / (double) n;
for (int i = 0; i < n; i++)
{
x.push_back(spline.evaluate(((double) i + 0.5) * dalpha) - rmin);
y.push_back(((double) i + 0.5) * dalpha);
}
convertToCartesian(x, y);
}
double *generateMap(galaxy *gals, int numGals, int numVoxelsPerDim, int xStart,
int yStart, int zStart, int boxLength, int **voxels){
// Allocate the voxel array.
*voxels = calloc(pow(numVoxelsPerDim, 3), sizeof(int));
// Convert the galaxy list to cartesian coordinates.
cartesianGalaxy *cartGals = convertToCartesian(gals, numGals);
// Loop through each galaxy and add it to the corresponding voxel.
double voxelLength = (double)boxLength/numVoxelsPerDim;
int ind;
#pragma omp parallel for
for(ind = 0; ind < numGals; ind++){
// Adjust the location of the galaxy.
double x = (cartGals+ind)->x - xStart;
double y = (cartGals+ind)->y - yStart;
double z = (cartGals+ind)->z - zStart;
// Calculate the index of the galaxy.
int i = x/voxelLength;
int j = y/voxelLength;
int k = z/voxelLength;
int index = i + numVoxelsPerDim*j + pow(numVoxelsPerDim, 2)*k;
// Increment the voxel at this location.
#pragma omp critical
(*(*voxels + index))++;
}
// Loop through each voxel and calculate the contrasts.
double p0 = numGals/pow(numVoxelsPerDim, 3);
double *map = calloc(pow(numVoxelsPerDim, 3), sizeof(double));
#pragma omp parallel for
for(ind = 0; ind < (int)pow(numVoxelsPerDim, 3); ind++){
if((*voxels)[ind] == 0){
map[ind] = -0.9;
}else{
*(map+ind) = (*(*voxels+ind) - p0)/p0;
}
}
return map;
}
/**
* Print the spline in (x,y) coordinates to a file named spline.txt.
*/
void SwarmCylinders::printSpline() const
{
double dalpha = 2.0 * M_PI / (double) M;
vector<double> xs;
vector<double> ys;
for (int i = 0; i < M; i++)
{
xs.push_back(spline.evaluate(((double) i + 0.5) * dalpha));
ys.push_back(((double) i + 0.5) * dalpha);
}
convertToCartesian(xs, ys);
FILE* fid;
fid = fopen("spline.txt", "w");
for (int i = 0; i < (int) xs.size(); i++)
{
fprintf(fid, "%10.6f %10.6f\n", xs[i], ys[i]);
}
fclose(fid);
}
/**
* Find the equilibrium after placing the cylinders in the domain somewhere.
* Iterates until tolerence is met.
*/
void SwarmCylinders::findEquilibrium()
{
double dalpha = 2.0 * M_PI / (double) M;
vector<double> m;
for (int i = 0; i < M; i++)
{
m.push_back(spline.evaluate(i * dalpha) * dalpha); /// assuming constant density charge on boundary
}
vector<double> xs;
vector<double> ys;
for (int i = 0; i < M; i++)
{
xs.push_back(spline.evaluate(((double) i + 0.5) * dalpha));
ys.push_back(((double) i + 0.5) * dalpha);
}
convertToCartesian(xs, ys);
int nIter = 0;
bool steadyState = false;
while (!steadyState)
{
vector<double> xNew;
vector<double> yNew;
const int xsize = x.size();
for (int i = 0; i < xsize; i++)
{
xNew.push_back(0.0);
yNew.push_back(0.0);
}
for (int i = 0; i < xsize; i++)
{
double u = 0.0;
double v = 0.0;
for (int j = 0; j < xsize; j++) /// from each body
{
if (i != j)
{
double norm = sqrt((x[i] - x[j]) * (x[i] - x[j]) + (y[i] - y[j]) * (y[i] - y[j]));
double factor = factorCylinder / (norm * norm * norm);
u += (x[i] - x[j]) * factor;
v += (y[i] - y[j]) * factor;
}
}
for (int j = 0; j < M; j++) /// from boundary
{
double norm = sqrt((x[i] - xs[j]) * (x[i] - xs[j]) + (y[i] - ys[j]) * (y[i] - ys[j]));
double factor = factorBoundary * m[j] / (norm * norm * norm);
u += (x[i] - xs[j]) * factor;
v += (y[i] - ys[j]) * factor;
}
xNew[i] = x[i] + dt * u;
yNew[i] = y[i] + dt * v;
}
convertToPolar(xNew, yNew);
for (int i = 0; i < xsize; i++)
{
const double rMax = spline.evaluate(yNew[i]) - radius;
if (rMax < xNew[i])
xNew[i] = 0.1 * rMax; /// move it toward (0,0)
// xNew[i] = min(spline.evaluate(yNew[i])-radius, xNew[i]); /// make it sit on the boundary if it is not repelled enough (not exactly correct)
}
convertToCartesian(xNew, yNew);
double maxNorm = 0.0;
for (int i = 0; i < xsize; i++)
{
double norm = sqrt((xNew[i] - x[i]) * (xNew[i] - x[i]) + (yNew[i] - y[i]) * (yNew[i] - y[i])); /// relative difference
maxNorm = max(norm, maxNorm);
}
for (int i = 0; i < xsize; i++)
{
x[i] = xNew[i];
y[i] = yNew[i];
}
// TODO Remove this testing shit, writing the positions each iteration
if (nIter % 10 == 0)
{
FILE* fidx;
FILE* fidy;
if (nIter == 0)
{
fidx = fopen("x.txt", "w");
fidy = fopen("y.txt", "w");
}
else
{
fidx = fopen("x.txt", "a");
fidy = fopen("y.txt", "a");
}
const int xsize = x.size();
for (int i = 0; i < xsize; ++i)
{
fprintf(fidx, "%e ", x[i]);
fprintf(fidy, "%e ", y[i]);
}
fprintf(fidx, "\n");
fprintf(fidy, "\n");
fclose(fidx);
fclose(fidy);
}
nIter++;
if (maxNorm <= threshold)
break;
if (nIter % 5000 == 0)
printf("** Norm at iteration %d: %e\n", nIter, maxNorm);
if (nIter > 50000)
{
printf("** Something is wrong, swarm shape is not converging quickly enough... aborting... \n");
abort();
}
}
printf("** Number of iterations to steady state formation: %d\n", nIter);
}