Python Forum

Hey,

I'm trying to plot a multi-gaussian function to some data, but the code runs a TypeError:

import numpy as np
import matplotlib.pyplot as plt
import pathlib
import os
from scipy.optimize import curve_fit

#Data
data = np.loadtxt('file.hst')
x = data[:,0]
y1 = data[:,1] # sync1
y2 = data[:,2] # sync2

n_gauss = 2

#Mean & width for y1 & y2
center = sum(x * y1) / sum(y1)
#mean = sum(x * y2) / sum(y2)
width = np.sqrt(sum(y1 * (x - center)**2) / sum(y1))
#width = np.sqrt(sum(y2 * (x - center)**2) / sum(y2))
#Functions:

def multi_gaussian(x, *gaussians):
    y = gaussians[0] * np.ones_like(x)
    n_gauss = (len(gaussians)-1) // 3
    for gauss in range(n_gauss):
        y += gaussian(x, gaussians[3*gauss+1], gaussians[3*gauss+2],
                      gaussians[3*gauss+3])
    return y

def gaussian(x, offset, area, center, width):
    y = offset + area * np.exp(-(x - center)**2 / (2 * width**2))
    return y
    
#Plots:
plt.plot(x, y1, label="sync1")
plt.plot(x, y2, label="sync2")
popt, pcov = curve_fit(gaussian, x, y1, p0=[5000, max(y1), center, width])
#popt, pcov = curve_fit(gaussian, x, y2, p0=[5000, max(y2), center, width])
#plt.plot(x, gaussian(y1, -2100, 3200, center, width),
#    lw=1, c='m', ls='--', label='Gaussian')
plt.plot(x, multi_gaussian(y1, -200, 3200, center, width),
    lw=1, c='r', ls='--', label='multi-Gaussian')
#plt.plot(x, gaussian(y2, 0, 2250, center, width),
#    lw=1, c='r', ls='--', label='Gaussian')
#plt.xlim([850, 980])
#plt.ylim([30, 600])
plt.legend()

The error I get is this:

    gaussians[3*gauss+3])

TypeError: gaussian() missing 1 required positional argument: 'width'

Fitting the single gaussian function works perfectly, but multi_gaussian doesn't work, no matter which n_gauss I use (the same error comes with n_gauss = 1 or 3, f.ex.). Am I not giving the multi_gaussian function enough values, or what could be wrong here? I tried removing offset in case it causes the error, but there is no difference.

The gaussian () function requires five parameters. On line 26/27 you call it with only four.

(Jun-16-2021, 01:54 PM)BashBedlam Wrote: [ -> ]The gaussian () function requires five parameters. On line 26/27 you call it with only four.

Oh man, I should've realized this the original gaussian I used for another code didn't have offset in it so I didn't put it in multi-gaussian either. Thanks!