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

227 lines
9.0 KiB
Python

from models.LIFACnoise import LifacNoiseModel
from CellData import CellData, icelldata_of_dir
from FiCurve import FICurve
from AdaptionCurrent import Adaption
from stimuli.SinusAmplitudeModulation import SinusAmplitudeModulationStimulus
import helperFunctions as hF
import numpy as np
from scipy.optimize import curve_fit, minimize
import functions as fu
import time
import matplotlib.pyplot as plt
def main():
for celldata in icelldata_of_dir("./data/"):
start_time = time.time()
fitter = Fitter(celldata)
fmin, parameters = fitter.fit_model_to_data()
print(fmin)
print(parameters)
end_time = time.time()
print('Fitting of cell took function took {:.3f} s'.format((end_time - start_time)))
break
pass
class Fitter:
def __init__(self, data: CellData, step_size=None):
if step_size is not None:
self.model = LifacNoiseModel({"step_size": step_size})
else:
self.model = LifacNoiseModel({"step_size": 0.05})
self.data = data
self.fi_contrasts = []
self.eod_freq = 0
self.modulation_frequency = 10
self.sc_max_lag = 1
# expected values the model has to replicate
self.baseline_freq = 0
self.vector_strength = -1
self.serial_correlation = []
self.f_infinities = []
self.f_infinities_slope = 0
# fixed values needed to fit model
self.a_tau = 0
self.a_delta = 0
self.counter = 0
self.calculate_needed_values_from_data()
def calculate_needed_values_from_data(self):
self.eod_freq = self.data.get_eod_frequency()
self.baseline_freq = self.data.get_base_frequency()
self.vector_strength = self.data.get_vector_strength()
self.serial_correlation = self.data.get_serial_correlation(self.sc_max_lag)
fi_curve = FICurve(self.data, contrast=True)
self.fi_contrasts = fi_curve.stimulus_value
self.f_infinities = fi_curve.f_infinities
self.f_infinities_slope = fi_curve.get_f_infinity_slope()
f_zero_slope = fi_curve.get_fi_curve_slope_of_straight()
self.a_delta = f_zero_slope / self.f_infinities_slope
adaption = Adaption(self.data, fi_curve)
self.a_tau = adaption.get_tau_real()
# mem_tau, (threshold?), (v_offset), noise_strength, input_scaling
def cost_function(self, X, tau_a=10, delta_a=3, error_scaling=()):
# set model parameters to the given ones:
self.model.set_variable("mem_tau", X[0])
self.model.set_variable("noise_strength", X[1])
self.model.set_variable("input_scaling", X[2])
self.model.set_variable("tau_a", tau_a)
self.model.set_variable("delta_a", delta_a)
# minimize the difference in baseline_freq first by fitting v_offset
v_offset = self.__fit_v_offset_to_baseline_frequency__()
self.model.set_variable("v_offset", v_offset)
# only eod with amplitude 1 and no modulation
base_stimulus = SinusAmplitudeModulationStimulus(self.eod_freq, 0, 0)
_, spiketimes = self.model.simulate_fast(base_stimulus, 30)
baseline_freq = hF.mean_freq_of_spiketimes_after_time_x(spiketimes, 5)
# print("model:", baseline_freq, "data:", self.baseline_freq)
relative_spiketimes = np.array([s % (1/self.eod_freq) for s in spiketimes])
eod_durations = np.full((len(spiketimes)), 1/self.eod_freq)
vector_strength = hF.__vector_strength__(relative_spiketimes, eod_durations)
serial_correlation = hF.calculate_serial_correlation(np.array(spiketimes), self.sc_max_lag)
f_infinities = []
for contrast in self.fi_contrasts:
stimulus = SinusAmplitudeModulationStimulus(self.eod_freq, contrast, self.modulation_frequency)
_, spiketimes = self.model.simulate_fast(stimulus, 0.5)
if len(spiketimes) < 2:
f_infinities.append(0)
else:
f_infinity = hF.mean_freq_of_spiketimes_after_time_x(spiketimes, 0.4)
f_infinities.append(f_infinity)
popt, pcov = curve_fit(fu.line, self.fi_contrasts, f_infinities, maxfev=10000)
f_infinities_slope = popt[0]
error_bf = abs((baseline_freq - self.baseline_freq) / self.baseline_freq)
error_vs = abs((vector_strength - self.vector_strength) / self.vector_strength)
error_sc = abs((serial_correlation[0] - self.serial_correlation[0]) / self.serial_correlation[0])
error_f_inf_slope = abs((f_infinities_slope - self.f_infinities_slope) / self.f_infinities_slope)
#print("vs:", vector_strength, self.vector_strength)
#print("sc", serial_correlation[0], self.serial_correlation[0])
#print("f slope:", f_infinities_slope, self.f_infinities_slope)
error_f_inf = 0
for i in range(len(f_infinities)):
error_f_inf += abs((f_infinities[i] - self.f_infinities[i]) / f_infinities[i])
error_f_inf = error_f_inf / len(f_infinities)
self.counter += 1
# print("mem_tau:", X[0], "noise:", X[0], "input_scaling:", X[2])
print("Cost function run times:", self.counter, "errors:", [error_bf, error_vs, error_sc, error_f_inf_slope, error_f_inf])
return error_bf + error_vs + error_sc + error_f_inf_slope + error_f_inf
def __fit_v_offset_to_baseline_frequency__(self):
test_model = self.model.get_model_copy()
voltage_step_size = 1000
simulation_time = 2
v_offset_start = 0
v_offset_current = v_offset_start
test_model.set_variable("v_offset", v_offset_current)
base_stimulus = SinusAmplitudeModulationStimulus(self.eod_freq, 0, 0)
_, spiketimes = test_model.simulate_fast(base_stimulus, simulation_time)
if len(spiketimes) < 5:
baseline_freq = 0
else:
baseline_freq = hF.mean_freq_of_spiketimes_after_time_x(spiketimes, simulation_time/2)
if baseline_freq < self.baseline_freq:
upwards = True
v_offset_current += voltage_step_size
else:
upwards = False
v_offset_current -= voltage_step_size
# search for a value below and above the baseline freq:
while True:
# print(self.counter, baseline_freq, self.baseline_freq, v_offset_current)
# self.counter += 1
test_model.set_variable("v_offset", v_offset_current)
base_stimulus = SinusAmplitudeModulationStimulus(self.eod_freq, 0, 0)
_, spiketimes = test_model.simulate_fast(base_stimulus, simulation_time)
if len(spiketimes) < 2:
baseline_freq = 0
else:
baseline_freq = hF.mean_freq_of_spiketimes_after_time_x(spiketimes, simulation_time/2)
if baseline_freq < self.baseline_freq and upwards:
v_offset_current += voltage_step_size
elif baseline_freq < self.baseline_freq and not upwards:
break
elif baseline_freq > self.baseline_freq and upwards:
break
elif baseline_freq > self.baseline_freq and not upwards:
v_offset_current -= voltage_step_size
elif baseline_freq == self.baseline_freq:
return v_offset_current
# found the edges use them to allow binary search:
if upwards:
lower_bound = v_offset_current - voltage_step_size
upper_bound = v_offset_current
else:
lower_bound = v_offset_current
upper_bound = v_offset_current + voltage_step_size
while True:
middle = lower_bound + (upper_bound - lower_bound)/2
# print(self.counter, "measured_freq:", baseline_freq, "wanted_freq:", self.baseline_freq, "current middle:", middle)
# self.counter += 1
test_model.set_variable("v_offset", middle)
base_stimulus = SinusAmplitudeModulationStimulus(self.eod_freq, 0, 0)
_, spiketimes = test_model.simulate_fast(base_stimulus, simulation_time)
if len(spiketimes) < 2:
baseline_freq = 0
else:
baseline_freq = hF.mean_freq_of_spiketimes_after_time_x(spiketimes, simulation_time/2)
if abs(baseline_freq - self.baseline_freq) < 1:
# print("close enough:", baseline_freq, self.baseline_freq, abs(baseline_freq - self.baseline_freq))
break
elif baseline_freq < self.baseline_freq:
lower_bound = middle
else:
upper_bound = middle
return middle
def fit_model_to_data(self):
x0 = np.array([20, 15, 75])
init_simplex = np.array([np.array([2, 1, 10]), np.array([40, 100, 140]), np.array([20, 50, 70]), np.array([150, 1, 200])])
fmin = minimize(fun=self.cost_function, x0=x0, args=(self.a_tau, self.a_delta), method="Nelder-Mead", options={"initial_simplex": init_simplex})
#fmin = minimize(fun=self.cost_function, x0=x0, args=(self.a_tau, self.a_delta), method="BFGS")
return fmin, self.model.get_parameters()
if __name__ == '__main__':
main()