void operator()(std::size_t begin_pool, std::size_t end_pool)
{
int poolStart, poolEnd, maxIndex;
float activation, currentActivation, derivative;
bool dropout = (dropoutMask.length() > 0);
for (int i = begin_pool; i < end_pool; i++)
{
poolStart = poolSize * i;
poolEnd = poolStart + (poolSize - 1);
for (int j = 0; j < colLength; j++)
{
activation = -INFINITY;
derivative = 0;
maxIndex = 0;
// Find maximum within pool
for (int k = 0; k < poolSize; k++)
{
currentActivation = activations(j, poolStart + k);
if (currentActivation > activation &&
(!dropout || dropoutMask[poolStart + k] == 1))
{
activation = currentActivation;
derivative = derivatives(j, poolStart + k);
maxIndex = k;
}
// Set everything to 0
activations(j, poolStart + k) = 0;
derivatives(j, poolStart + k) = 0;
}
// Restore maximum
if (activation != -INFINITY)
{
activations(j, poolStart + maxIndex) = activation;
derivatives(j, poolStart + maxIndex) = derivative;
}
}
}
}
