A Population
object represents a group of identical neurons. It is associated with a geometry (defining the number of neurons and optionally its spatial structure), a neuron type and optionally a name.
ANNarchy.
Population
(geometry, neuron, name=None, stop_condition=None, storage_order='post_to_pre', copied=False)[source]¶Represents a population of homogeneous neurons.
Parameters:
ANNarchy.Neuron
clear
()[source]¶Clears all spiking events previously emitted (history of spikes, delayed spikes).
Can be useful if you do not want to totally reset a population (i.e. all variables), only to clear the spiking history between two trials.
Note: does nothing for rate-coded networks.
compute_firing_rate
(window)[source]¶Tells spiking neurons in the population to compute their mean firing rate over the given window and store the values in the variable r.
This method has an effect on spiking neurons only.
If this method is not called, r will always be 0.0. r can of course be accessed and recorded as any other variable.
Parameter:
coordinates_from_rank
(rank)[source]¶Returns the coordinates of a neuron based on its rank.
Parameter:
disable
()[source]¶Temporarily disables computations in this population (including the projections leading to it).
You can re-enable it with the enable()
method.
enable
()[source]¶(Re)-enables computations in this population, after they were disabled by the disable()
method.
The status of the population is accessible through the enabled
flag.
get
(name)[source]¶Returns the value of neural variables and parameters.
Parameter:
load
(filename)[source]¶Load the saved state of the population.
Warning: Matlab data can not be loaded.
Parameters:
Example:
pop.load('pop1.txt')
neuron
(*coord)[source]¶Returns an IndividualNeuron
object wrapping the neuron with the provided rank or coordinates.
normalized_coordinates_from_rank
(rank, norm=1.0)[source]¶Returns normalized coordinates of a neuron based on its rank. The geometry of the population is mapped to the hypercube [0, 1]^d.
Parameters:
rank_from_coordinates
(coord)[source]¶Returns the rank of a neuron based on coordinates.
Parameter:
reset
(attributes=-1)[source]¶Resets all parameters and variables of the population to the value they had before the call to compile().
Parameters:
save
(filename)[source]¶Saves all information about the population (structure, current value of parameters and variables) into a file.
Parameter:
Warning
The ‘.mat’ data will not be loadable by ANNarchy, it is only for external analysis purpose.
Example:
pop.save('pop1.txt')
set
(values)[source]¶Sets the value of neural variables and parameters.
Parameter:
set({ 'tau' : 20.0, 'r'= np.random.rand((8,8)) } )
sum
(target)[source]¶Returns the array of weighted sums corresponding to the target:
excitatory = pop.sum('exc')
For spiking networks, this is equivalent to accessing the conductances directly:
excitatory = pop.g_exc
If no incoming projection has the given target, the method returns zeros.
Parameter:
Note: it is not possible to distinguish the original population when the same target is used.
neurons
¶Returns iteratively each neuron in the population.
For instance, if you want to iterate over all neurons of a population:
>>> for neur in pop.neurons:
... neur.r = 0.0
Alternatively, one could also benefit from the __iter__
special command. The following code is equivalent:
>>> for neur in pop:
... neur.r = 0.0