void QuatJulia::generate()
{
/// eval at uniform grid
int i, j, k;
const float grid = 1.f / (float)m_numGrid;
const Vector3F origin(-.5f+grid * .5f,
-.5f+grid * .5f,
-.5f+grid * .5f);
int n = 0;
for(k=0; k<m_numGrid; ++k ) {
for(j=0; j<m_numGrid; ++j ) {
for(i=0; i<m_numGrid; ++i ) {
Vector3F sample = origin + Vector3F(grid * i, grid * j, grid * k);
if( evalAt( sample*3.2f ) > 0.f ) {
n++;
cvx::Sphere sp;
sample *= m_scaling;
sp.set(sample, .001f);
m_tree->insert((const float *)&sample, sp);
}
}
}
}
m_tree->finishInsert();
}
void DifferenceJob::run()
{
for(int y = y1; y < y2; y++)
for(int x = x1; x < x2; x++)
(*dst)[y][x] = evalAt(x,y);
/* warning: thread-unsafe! */
if(progress_done)
progress((*progress_done) += progress_step);
}
void PolyModel::findMinimum(double mins[], double maxs[]) {
const double learnRate = 0.001;
const int numRestarts = 50;
double *width = new double[numVars];
for (int i=0; i<numVars; i++) {
assert (mins[i] <= maxs[i]);
width[i] = maxs[i] - mins[i];
}
double *pos = new double[numVars];
double *step = new double[numVars];
double valAtPos;
argMin = new double[numVars];
double lowestVal;
bool lowestValValid = false;
for (int i=0; i<numRestarts; i++) {
for (int j=0; j<numVars; j++)
pos[j] = Param::DRand(mins[j], maxs[j]);
valAtPos = evalAt(pos);
bool done = false;
while (!done) {
for (int j=0; j<numVars; j++) {
step[j] = -(derivAt(pos, j) * learnRate * width[j]);
}
for (int j=0; j<numVars; j++) {
pos[j] += step[j];
if (pos[j] < mins[j])
pos[j] = mins[j];
else if (pos[j] > maxs[j])
pos[j] = maxs[j];
}
double valAtLastPos = valAtPos;
valAtPos = evalAt(pos);
if (valAtPos >= valAtLastPos)
done = true;
}
if (!lowestValValid || valAtPos < lowestVal) {
for (int j=0; j<numVars; j++)
argMin[j] = pos[j];
lowestVal = valAtPos;
lowestValValid = true;
}
}
minimumKnown = true;
minimum = lowestVal;
delete[] width;
delete[] pos;
delete[] step;
}
