/**
* Perform a uniform shuffle of a vector.
*
* @tparam random_t Type of the random number generator
* @tparam Vector Type of the vector. Must implement size() and operator[].
* For example: std::vector of std::deque
* @param [in,out] gen the rng
* @param [in,out] vec the vector
*
* @return An uint32.
**/
template<class Vector, class random_t> inline void randomShuffle(Vector & vec, random_t & gen)
{
const size_t l = vec.size();
if (l < 2) return;
for (size_t i = l - 1; i > 0; --i)
{
size_t j = (size_t)(Unif(gen)*(i + 1));
typename std::remove_reference<decltype(vec[0])>::type temp(vec[i]);
vec[i] = vec[j];
vec[j] = temp;
}
}
/**************************************************************
*
* Perform the walk until the range increases by nb
*
***************************************************************/
void makeWalk(int64 nb,bool displayProgress = true)
{
ProgressBar<uint64> * PB = nullptr;
if (displayProgress) { PB = new ProgressBar<uint64>(nb, "Simulating..."); }
nb += N;
auto startN = N;
int64 lastb = 0;
char v = G(pos); // current site
while (N < nb)
{
if (isFull(v))
{ // the four edge around the site are set, do simple rw
if (lastb < 100)
{ // boundary not a long time ago, just one step
SRW_Z2_1step(pos, gen);
lastb++;
}
else
{
int64 d;
do
{
iBox2 fullR;
G.findFullBoxCentered(pos, fullR); // find a full box
fullR.min[0]--; fullR.max[0]++; fullR.min[1]--; fullR.max[1]++;
d = SRW_Z2_MoveInRect(pos, fullR, 8, gen); // move in the rectangle
}
while (d > 0);
}
v = G(pos);
}
else
{ // not all egdes are set, do ERRW
lastb = 0; // reset the last visit to boundary
const double up = ((v & maskup) ? delta : 1.0);
const double right = ((v & maskright) ? delta : 1.0);
const double down = ((v & maskdown) ? delta : 1.0);
const double left = ((v & maskleft) ? delta : 1.0);
const double a = Unif(gen)*(up + right + down + left);
if (a < up + right)
{
if (a < up)
{
if ((v & maskup) == 0) { G.set(pos, v | maskup); pos.Y()++; v = G(pos); if (isEmpty(v)) { N++; if (PB != nullptr) { PB->update(N - startN); } } v |= maskdown; G.set(pos, v); }
else { pos.Y()++; v = G(pos); }
}
else
{
if ((v & maskright) == 0) { G.set(pos, v | maskright); pos.X()++; v = G(pos); if (isEmpty(v)) { N++; if (PB != nullptr) { PB->update(N - startN); } } v |= maskleft; G.set(pos, v); }
else { pos.X()++; v = G(pos); }
}
}
else
{
if (a < up + right + down)
{
if ((v & maskdown) == 0) { G.set(pos, v | maskdown); pos.Y()--; v = G(pos); if (isEmpty(v)) { N++; if (PB != nullptr) { PB->update(N - startN); } } v |= maskup; G.set(pos, v); }
else { pos.Y()--; v = G(pos); }
}
else
{
if ((v & maskleft) == 0) { G.set(pos, v | maskleft); pos.X()--; v = G(pos); if (isEmpty(v)) { N++; if (PB != nullptr) { PB->update(N - startN); } } v |= maskright; G.set(pos, v); }
else { pos.X()--; v = G(pos); }
}
}
}
}
delete PB;
}
