# Python Python the Voigt Profile

1. Apr 2, 2015

### sketos

I very new to python and this might look relatively easy to some of you. I need to write a code so that

$$H(a,u) = \frac{a}{\pi} \int_{-\infty}^{\infty} \frac{e^{-y^2}}{a^2+(u-y)^2}dy$$

it plots the above function for different values of the a parameter, so that ultimately i will have a graph of 3 or more function of the form $H(a_1,u)$, $H(a_2,u)$, $H(a_3,u)$ as functions of u. Can anyone provide a code ?

2. Apr 2, 2015

### Staff: Mentor

The key is
We're not going to do this for you. We'll be happy to help you out on it, but you need to show us what you've tried.

3. Apr 3, 2015

### sketos

import numpy as np
import pylab as pl
from math import exp
from scipy.integrate import quad

def voigt( u , a ):

def integrand( y ):

return exp(-y**2)/( a**2 + ( u - y )**2 )

return quad( integrand ,-np.inf , np.inf )

x = np.linspace(-100 , 100 )

Func = voigt( x , 0.1 )

pl.plot( x , Func )

pl.show()

This is as far as i got before i posted...

4. Apr 3, 2015

### Fooality

Teach a man to fish he eats for a lifetime. Here's some important tools to breaking it down. I suck at calculus so I use this to calculate integrals.
http://integrals.wolfram.com/index.jsp
You would enter it in the Wolfram language, where x^y means x to the power of y, remember your parenthesis. Then take the output, and code it in the python language...its the same except x**y = x to the power of y.

5. Apr 6, 2015