fit multiple parametric curves with scipy python

Question

I am trying to fit two curve into one equation. y = (a * exp(b * (T^-1)))cexp(d100)(x^0.5)

for y1, T =10, for y2, T =25.

how do a get a,b,c,d

I have a code that simplified to fit one data. I don't know how to do both. I find a similar question with solution but I can't follow.. fit multiple parametric curves with scipy

import matplotlib.pyplot as plt from scipy.optimize import curve_fit from scipy.optimize import leastsq import numpy as np import pandas as pd from math import exp def func(params,x,y): a, b, c, d = params[0], params[1], params[2],params[3] return y-(a*exp(b*(10**-1)))*c*exp(d*100)*(x**0.5) x = [0,33,65,98,135,261,374] y = [0.000,0.006,0.010,0.018,0.023,0.033,0.035] y2 = [0.000,0.013,0.032,0.036,0.042,0.046,0.051] plt.scatter(x,y, label='y1') plt.scatter(x,y2, label='y1') params=[0, 0, 0, 0] result = leastsq(func, params, (x, y)) a, b, c, d = result[0][0], result[0][1], result[0][2], result[0][3] yfit1 = (a*exp(b*(25**-1)))*c*exp(d*100)*(x**0.5) plt.plot(x, yfit1, color="red") print (b,c,d) plt.xlabel('x') plt.ylabel('y') plt.legend() plt.grid() plt.show()

danmohad · Accepted Answer · 2022-09-28 00:25:28Z

You need to include T in the independent variable being passed to curve_fit. Also, you should use numpy mathematical functions in func.

import matplotlib.pyplot as plt from scipy.optimize import curve_fit import numpy as np def func(xT, a, b, c, d,): x = xT[0,:] T = xT[1,:] return a * np.exp(b * np.power(T, -1)) * c * np.exp(d * 100.0) * np.power(x, 0.5) x0 = np.array([0,33,65,98,135,261,374]) y1 = np.array([0.000,0.006,0.010,0.018,0.023,0.033,0.035]) T1 = 10.0 * np.ones(len(x0)) y2 = np.array([0.000,0.013,0.032,0.036,0.042,0.046,0.051]) T2 = 25.0 * np.ones(len(x0)) x = np.concatenate((x0, x0)) y = np.concatenate((y1, y2)) T = np.concatenate((T1, T2)) popt, _ = curve_fit(func, np.vstack((x, T)), y) N = 101 # number of points for parametric curves x_ = np.linspace(np.min(x0), np.max(x0), N) y1_ = func(np.vstack((x_, 10.0 * np.ones(N))), *popt) plt.plot(x0, y1, 'k.') plt.plot(x_, y1_, 'k-') y2_ = func(np.vstack((x_, 25.0 * np.ones(N))), *popt) plt.plot(x0, y2, 'b.') plt.plot(x_, y2_, 'b-')

Collectives™ on Stack Overflow

fit multiple parametric curves with scipy python

1 Answer 1

Comments

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Linked

Related