P-unit_model/models/LIFACnoise.py
2020-02-14 14:33:58 +01:00

222 lines
7.2 KiB
Python

from stimuli.AbstractStimulus import AbstractStimulus
from models.AbstractModel import AbstractModel
import numpy as np
import functions as fu
from numba import jit
import time
class LifacNoiseModel(AbstractModel):
# all times in milliseconds
# possible mem_res: 100 * 1000000 exact value unknown in p-units
DEFAULT_VALUES = {"mem_tau": 20,
"v_base": 0,
"v_zero": 0,
"threshold": 1,
"v_offset": 50,
"input_scaling": 1,
"delta_a": 0.4,
"tau_a": 40,
"a_zero": 0,
"noise_strength": 3,
"step_size": 0.01}
def __init__(self, params: dict = None):
super().__init__(params)
self.voltage_trace = []
self.adaption_trace = []
self.spiketimes = []
self.stimulus = None
# self.frequency_trace = []
def simulate(self, stimulus: AbstractStimulus, total_time_s):
self.stimulus = stimulus
output_voltage = []
adaption = []
spiketimes = []
current_v = self.parameters["v_zero"]
current_a = self.parameters["a_zero"]
for time_point in np.arange(0, total_time_s*1000, self.parameters["step_size"]):
# rectified input:
stimulus_strength = fu.rectify(stimulus.value_at_time_in_ms(time_point))
v_next = self._calculate_voltage_step(current_v, stimulus_strength - current_a)
a_next = self._calculate_adaption_step(current_a)
if v_next > self.parameters["threshold"]:
v_next = self.parameters["v_base"]
spiketimes.append(time_point/1000)
a_next += self.parameters["delta_a"] / (self.parameters["tau_a"] / 1000)
output_voltage.append(v_next)
adaption.append(a_next)
current_v = v_next
current_a = a_next
self.voltage_trace = output_voltage
self.adaption_trace = adaption
self.spiketimes = spiketimes
return output_voltage, spiketimes
def simulate_fast(self, stimulus: AbstractStimulus, total_time_s):
v_zero = self.parameters["v_zero"]
a_zero = self.parameters["a_zero"]
step_size = self.parameters["step_size"]
threshold = self.parameters["threshold"]
v_base = self.parameters["v_base"]
delta_a = self.parameters["delta_a"]
tau_a = self.parameters["tau_a"]
v_offset = self.parameters["v_offset"]
mem_tau = self.parameters["mem_tau"]
noise_strength = self.parameters["noise_strength"]
stimulus_array = stimulus.as_array(total_time_s, step_size)
parameters = np.array([v_zero, a_zero, step_size, threshold, v_base, delta_a, tau_a, v_offset, mem_tau, noise_strength])
voltage_trace, adaption, spiketimes = simulate_fast(stimulus_array, total_time_s, parameters)
self.stimulus = stimulus
self.voltage_trace = voltage_trace
self.adaption_trace = adaption
self.spiketimes = spiketimes
return voltage_trace, spiketimes
def _calculate_voltage_step(self, current_v, input_v):
v_base = self.parameters["v_base"]
step_size = self.parameters["step_size"]
v_offset = self.parameters["v_offset"]
mem_tau = self.parameters["mem_tau"]
noise_strength = self.parameters["noise_strength"]
noise_value = np.random.normal()
noise = noise_strength * noise_value / np.sqrt(step_size)
return current_v + step_size * ((v_base - current_v + v_offset + input_v + noise) / mem_tau)
def _calculate_adaption_step(self, current_a):
step_size = self.parameters["step_size"]
return current_a + (step_size * (-current_a)) / self.parameters["tau_a"]
def min_stimulus_strength_to_spike(self):
return self.parameters["threshold"] - self.parameters["v_base"]
def get_sampling_interval(self):
return self.parameters["step_size"]
def get_frequency(self):
# TODO also change simulates_frequency() if any calculation is added!
raise NotImplementedError("No calculation implemented yet for the frequency.")
def get_spiketimes(self):
return self.spiketimes
def get_voltage_trace(self):
return self.voltage_trace
def get_adaption_trace(self):
return self.adaption_trace
def simulates_frequency(self) -> bool:
return False
def simulates_spiketimes(self) -> bool:
return True
def simulates_voltage_trace(self) -> bool:
return True
def get_recording_times(self):
# [delay, stimulus_start, stimulus_duration, time_to_end]
self.stimulus = AbstractStimulus()
delay = 0
start = self.stimulus.get_stimulus_start_s()
duration = self.stimulus.get_stimulus_duration_s()
total_time = len(self.voltage_trace) / self.parameters["step_size"]
return [delay, start, duration, total_time]
def get_model_copy(self):
return LifacNoiseModel(self.parameters)
def calculate_baseline_markers(self, stimulus_freq=750):
"""
calculates the baseline markers baseline frequency, vector strength and serial correlation
based on simulated 30 seconds with a standard Sinusoidal stimulus with the given frequency
:return: baseline_freq, vs, sc
"""
pass
def calculate_fi_markers(self, contrasts, ):
"""
calculates the fi markers f_infinity, f_infinity_slope for given contrasts
based on simulated 2 seconds for each contrast
:return:
"""
def stimulus_to_numpy_array(stimulus: AbstractStimulus, total_time_s, step_size):
total_time_points = int(total_time_s * 1000 / step_size)
stimulus_values = np.zeros(total_time_points)
for idx in range(len(stimulus_values)):
# rectified input:
stimulus_values[idx] = fu.rectify(stimulus.value_at_time_in_ms(step_size*idx))
return stimulus_values
@jit(nopython=True)
def simulate_fast(rectified_stimulus_array, total_time_s, parameters: np.ndarray):
v_zero = parameters[0]
a_zero = parameters[1]
step_size = parameters[2]
threshold = parameters[3]
v_base = parameters[4]
delta_a = parameters[5]
tau_a = parameters[6]
v_offset = parameters[7]
mem_tau = parameters[8]
noise_strength = parameters[9]
time = np.arange(0, total_time_s * 1000, step_size)
length = len(time)
output_voltage = np.zeros(length)
adaption = np.zeros(length)
stimulus_values = rectified_stimulus_array
spiketimes = []
output_voltage[0] = v_zero
adaption[0] = a_zero
for i in range(len(time)-1):
noise_value = np.random.normal()
noise = noise_strength * noise_value / np.sqrt(step_size)
output_voltage[i] = output_voltage[i-1] + ((v_base - output_voltage[i-1] + v_offset + stimulus_values[i] - adaption[i-1] + noise) / mem_tau) * step_size
adaption[i] = adaption[i-1] + ((-adaption[i-1]) / tau_a) * step_size
if output_voltage[i] > threshold:
output_voltage[i] = v_base
spiketimes.append(i*step_size)
adaption[i] += delta_a / (tau_a / 1000)
return output_voltage, adaption, spiketimes