/* sweep_lattice_disorder()
* Performans Monte Carlo sweeps. Sweeps the lattice once by choosing a random position and
* proposing a spin flip using the Meteropolis Algorithm. This is done for the lattice size.
*/
void Clock2::sweep_lattice_disorder(float beta, std::mt19937 &engine)
{
for (size_t i = 0; i < size; i++) {
size_t pos = static_cast<size_t>(rand0(engine) * size);
// Compute new angle
int new_angle;
do {
new_angle = static_cast<int>(rand0(engine) * q);
} while(new_angle == spin[pos]);
// Compute energy change
float delta_E = 0.0;
for (size_t i = 0; i < n_neigh; i++) {
size_t neigh_angle = spin[neigh[pos].neighbor[i]];
size_t old_angle = spin[pos];
size_t old_idx = (old_angle - neigh_angle + q) % q;
size_t new_idx = (new_angle - neigh_angle + q) % q;
delta_E += J[pos].J_arr[i] * (cos_val[old_idx] - cos_val[new_idx]);
}
// Accept / reject new spin
if (rand0(engine) < exp(-beta * delta_E))
spin[pos] = new_angle;
}
}
int main(int argc, char const *argv[])
{
int count;
for(count = 0; count < 5; count++)
printf("%hd\n", rand0());
return 0;
}
/* set_spin()
* Sets the angle index representing the spin
*/
void Clock2::set_spin()
{
std::random_device rd;
std::mt19937 engine(rd());
for (size_t i = 0; i < size; i++)
spin[i] = static_cast<int>(rand0(engine) * q);
}
int main(void)
{
int count;
for (count = 0; count < 5; count++)
printf("%d\n", rand0());
return 0;
}
/* boxmuller transform. Turns uniform random numbers into
* normally distributed random numbers, with mean 0 and
* standard deviation 1.
*/
float gauss0(long *seed)
{
float x1, x2, y1, r, fac;
static float y2;
static int flag = 0;
if (flag) {
flag = 0;
return y2;
}
do {
x1 = rand0(seed)*2 - 1;
x2 = rand0(seed)*2 - 1;
r = x1*x1 + x2*x2;
} while (r >= 1);
fac = sqrt((-2*log(r)/r));
y1 = x1*fac;
y2 = x2*fac;
flag = 1;
return y1;
}
std::vector<Node*>
DispersalFunctions::populate(std::vector<Node*> thisGeneration, int generation)
{
std::vector<Node*> children;
float x,y;//,mindistance;
//int j_x;
float distance;
int numberOfChildren;
// bool ismin;
bool *paired = new bool[thisGeneration.size()];
std::vector<NodePair> pairs;
float cutoff = 90;
int numFemale = 0;
for (unsigned int i = 0; i < thisGeneration.size(); i++)
paired[i] = false;
for (unsigned int i = 0; i < thisGeneration.size(); i++)
{
// mindistance =std::numeric_limits<float>::max();
//ismin = false;
//j_x = 0;
if( thisGeneration[i]->_male == false && paired[i] == false)
{
numFemale++;
for (unsigned int j = 0; j < thisGeneration.size(); j++)
{
if(thisGeneration[j]->_male == true && paired[j] == false)
{
x= (thisGeneration[i])->lat -(thisGeneration[j])->lat;
y= (thisGeneration[i])->lon - (thisGeneration[j])->lon;
distance = x*x+y*y;
if(distance < cutoff) {
NodePair x(i,j,distance);
x._tmpDistance = 1.0/distance;
pairs.push_back(x);
}
}
}
/* if(ismin) {
paired[i] = true;
paired[j_x] = true;
numberOfChildren = settings->getNOffspring(generation, _rand);
for (int j = 0; j < numberOfChildren; j++)
{
Node *child = new Node(generation + 1, thisGeneration[i], thisGeneration[j_x]);
(thisGeneration[i])->children.push_back(child);
(thisGeneration[j_x])->children.push_back(child);
children.push_back(child);
}
}*/
}
}
Random rand0(42);
for(int j=1;j<pairs.size();j++)
{
pairs[j]._tmpDistance += pairs[j-1]._tmpDistance;
}
double sum = pairs[pairs.size()-1]._tmpDistance;
for(int i=0;i< 10000 && numFemale > 0 && pairs.size() > 0;i++) {
NodePair asdasd(0,0,0);
asdasd._tmpDistance =rand0.nextFloat()*sum;
std::vector<NodePair>::iterator tmp = std::lower_bound(pairs.begin(), pairs.end(),asdasd);
paired[tmp->indexFemale] = true;
paired[tmp->indexMale] = true;
numFemale--;
numberOfChildren = settings->getNOffspring(generation, _rand);
for (int j = 0; j < numberOfChildren; j++)
{
Node *child = new Node(generation + 1, thisGeneration[tmp->indexFemale], thisGeneration[tmp->indexMale]);
(thisGeneration[tmp->indexFemale])->children.push_back(child);
(thisGeneration[tmp->indexMale])->children.push_back(child);
children.push_back(child);
}
if(i%(int)(log(thisGeneration.size())*log(thisGeneration.size())) == 0) { //todo:
std::vector<NodePair> newPairs;
for(int j=0;j<pairs.size();j++) {
if(paired[pairs[j].indexFemale] == false && paired[pairs[j].indexMale] == false) {
if(!newPairs.empty())
pairs[j]._tmpDistance = 1.0/pairs[j]._distance + newPairs[newPairs.size()-1]._tmpDistance;
else pairs[j]._tmpDistance = 1.0/pairs[j]._distance;
newPairs.push_back(pairs[j]);
}
}
pairs.clear();
pairs = newPairs;
sum = pairs[pairs.size()-1]._tmpDistance;
}
}
delete[] paired;
return children;
}