Calcium_Model/fitter.py

import time
import numpy as np
import pylab as plt
import pandas as pd
import re

from scipy.optimize import least_squares
from Model import Model
from Data import Data


class Fitter:
    def __init__(
        self, model: Model, data: Data, current_fit_range: tuple = (107, 341)
    ) -> None:
        """
        current_fit_range : tuple (t0, t1), t0 nad t1 are start and stop times in between current is fitted
        """

        self.model = model
        self.data = data
        self.current_fit_range = current_fit_range
        self.fit_results = {}

        self.tspan = [0, 1000]
        self.dt = 1  # 1.0
        self.time_points = np.arange(*self.tspan, self.dt)

        model = Model()
        self.initial_values = model.get_initial_values()

        self.iteration = 0  # least squares iteration counter

        t0, t1 = self.current_fit_range = current_fit_range
        self.current_time_indecies = (t0 <= self.time_points) & (self.time_points <= t1)
        self.measured_current = self.data.get_current_slice(
            self.time_points[self.current_time_indecies] / 1000
        )  # calculating in ms but data recorded in sec

    def convolve_current(self, current: np.ndarray, tau=1.5):
        if np.abs(tau) < 1e-8:
            return current

        k = np.zeros(current.size)
        k[k.size // 2:] = np.exp(-np.arange(k.size // 2) / np.abs(tau))
        k /= k.sum()

        if tau > 0:
            return np.convolve(current, k, mode="same")
        else:
            return np.convolve(current, k[::-1], mode="same")

    def cost_func(self, parameters: np.ndarray):

        model = self.model()

        gGaL, ECal, K_pc_half, tau_xfer, tau_RC, offset = parameters

        model.ECaL = ECal
        model.gCaL = gGaL
        model.K_pc_half = K_pc_half
        model.tau_xfer = tau_xfer

        model.solve(
            times=self.time_points,
            tspan=self.tspan,
            dt=self.dt,
            initial_values=self.initial_values
        )

        states = self.initial_values

        V = self.model.mem_potential(t)
        _calc_curr = model.calculated_current(states, t, V)
        calculated_current = (
            self.convolve_current(_calc_curr, tau=tau_RC)[self.current_time_indecies]
            + offset
        )

        res = self.measured_current - calculated_current
        err = np.mean(res**2)  # mean squared error
        self.iteration += 1
        print(self.iteration, parameters.tolist(), "err", err)

        if self.iteration < -0:
            t = self.time_points[self.current_time_indecies]
            plt.plot(
                t, _calc_curr[self.current_time_indecies], label="calculated current"
            )
            plt.plot(t, self.measured_current, label="measured current")
            plt.plot(t, calculated_current, label="conv calculated current")
            plt.plot(t, self.measured_current - calculated_current, label="error")
            plt.xlabel("time, ms")
            plt.ylabel("current, pA/pF")
            plt.legend(frameon=False)
            plt.show()

        return res  # , measured_fluo - calculated_fluo)

    def optimize(self, init_parameters=None):
        t0 = time.time()
        self.iteration = 0
        if init_parameters is None:
            m = self.model()
            K_pc_half = m.K_pc_half
            tau_xfer = m.tau_xfer
            tau_RC = 1.5
            offset = 0

            d = self.data
            init_parameters = np.array(
                [d.gGaL, d.ECal, K_pc_half, tau_xfer, tau_RC, offset]
            )
            print(init_parameters.tolist())

        bounds = (
            (0.01, 10, 0.1, 0.1, -5, -10),
            (10, 100, 100, 100, 10, 10),
        )

        res = least_squares(self.cost_func, init_parameters, bounds=bounds, xtol=1e-10)
        print()
        print("   Parameters: [gGaL, ECal, K_pc_half, tau_xfer, tau_RC, offset]")
        print("      Initial:", init_parameters.tolist())
        print("    Optimized:", res.x.tolist())
        print(" Optim status:", res.status)
        print("Optim message:", res.message)

        gGaL, ECal, K_pc_half, tau_xfer, tau_RC, offset = res.x

        err = self.cost_func(res.x)

        self.fit_results.update(
            {
                "gGaL": gGaL,
                "ECal": ECal,
                "K_pc_half": K_pc_half,
                "tau_xfer": tau_xfer,
                "tau_RC": tau_RC,
                "offset": offset,
                "mean_squared_error": np.mean((err) ** 2),
            }
        )

        model = self.model()

        model.ECaL = ECal
        model.gCaL = gGaL
        model.K_pc_half = K_pc_half
        model.tau_xfer = tau_xfer

        model.solve(times=self.time_points)

        _calc_curr = model.calculated_current()
        calculated_current = self.convolve_current(_calc_curr, tau=tau_RC) + offset
        print("Elapsed time:", time.time() - t0)

        fig = plt.figure(figsize=(6, 3))
        ax1 = fig.add_subplot(121)
        ax2 = fig.add_subplot(122)
        ax1.plot(1000 * self.data.current_t, self.data.current, label="Mõõdetud")
        ax1.plot(self.time_points, calculated_current, label="Arvutatud")
        ax1.set_xlabel("Aeg [ms]")
        ax1.set_ylabel("Vool [pA/pF]")
        ax1.legend(frameon=False)

        tp = self.time_points[self.current_time_indecies]
        ax2.plot(tp, self.measured_current, label="Mõõdetud")
        ax2.plot(tp, calculated_current[self.current_time_indecies], label="Arvutatud")
        ax2.set_xlabel("Aeg [ms]")
        ax2.set_ylabel("Vool [pA/pF]")
        ax2.legend(frameon=False)
        return res, fig

    def covcor_from_lsq(res):

        _, s, VT = np.linalg.svd(res.jac, full_matrices=False)
        threshold = np.finfo(float).eps * max(res.jac.shape) * s[0]
        s = s[s > threshold]
        VT = VT[: s.size]
        cov = np.dot(VT.T / s**2, VT)

        std = np.sqrt(np.diag(cov))
        cor = cov / np.outer(std, std)
        cor[cov == 0] = 0

        return cov, cor

    def plot_correlation_matrix(cor):
        plt.imshow(cor, cmap="viridis", interpolation="nearest")
        plt.colorbar(label="Correlation")
        plt.title("Correlation Matrix")
        plt.xlabel("Variables")
        plt.ylabel("Variables")
        plt.show()


if __name__ == "__main__":

    filename = "ltcc_current.h5"
    eid = "1c5ca4b12ae2ddffc3960c1fe39a3cce35967ce23dbac57c010f450e796d01fd_2017.11.27 14:07:04"

    data = Data(filename, eid)

    fit = Fitter(Model, data)

    res, fig = fit.optimize()

    fit_hist = pd.DataFrame.from_dict(fit.fit_results, orient="index").T
    fit_hist.index.name = "Iterations"

    res_filename = f"fit_results_{eid}.csv"
    res_filename = res_filename.replace(" ", "_").replace(":", "-")
    fit_hist.to_csv(res_filename, index=True)

    eid_cleaned = re.sub(r"[^\w.-]", "", eid)  # Eemaldab eritahed
    fig.savefig(f"plot_{eid_cleaned}.png")
    fig.savefig(f"plot_{eid_cleaned}.pdf")

    # plot_filename = "fit_plot"
    # fig.savefig(f"{plot_filename}.png")
    # fig.savefig(f"{plot_filename}.pdf")
    fig.savefig("naidis_fit.pdf")
    plt.show()