void place_cell_generator::update(Time const & T, const long_t from, const long_t to)
{
assert(to >= 0 && (delay) from < Scheduler::get_min_delay());
assert(from < to);
for (long_t lag = from; lag < to; ++lag)
{
long_t now = T.get_steps() + lag;
if (device_.is_active(T + Time::step(lag)))
{
librandom::RngPtr rng = net_->get_rng(get_thread());
ulong_t n_spikes = poisson_dev_.uldev(rng);
if (n_spikes > 0) // we must not send events with multiplicity 0
{
nest::SpikeEvent se;
se.set_multiplicity(n_spikes);
network()->send(*this, se, lag);
}
// Advance the positional information if there is space in the
// positional vector
if (now >= next_pos_step) {
next_pos_step = now + sim_dt_per_pos_dt;
if (pos_it < P_.rat_pos_x.size() - 1)
pos_it++;
setFiringRate();
}
}
}
}
void Neuron::updateFiringRateLinear()
{
// IDEA: it might speed things up to keep track of whether the
// input sum has changed, then only update things if it has.
// The Neuron::setFiringRate should at least avoid updating
// post-synaptic input sums when the firing rate hasn't changed.
// Just use the linear function firing rate = input sum.
setFiringRate(mSynapticInputSum);
}
void Neuron::updateFiringRateSigmoid()
{
// IDEA: it might speed things up to keep track of whether the
// input sum has changed, then only update things if it has.
// The Neuron::setFiringRate should at least avoid updating
// post-synaptic input sums when the firing rate hasn't changed.
// Sigmoid function. Avoid overflow.
if (mSynapticInputSum < -500)
{
setFiringRate(0);
}
else if (mSynapticInputSum > 500)
{
setFiringRate(1);
}
else
{
setFiringRate(1 / (1 + globals::exp(-mSynapticInputSum)));
}
}
void place_cell_generator::calibrate()
{
device_.calibrate();
double sim_dt = Time::get_resolution().get_ms();
// Calibrate how often to advance the positional index
sim_dt_per_pos_dt = (int) (P_.rat_pos_dt / sim_dt);
next_pos_step = sim_dt_per_pos_dt;
pos_it = 0;
setFiringRate();
}
