In [1]:

    

%pylab


    

    




Using matplotlib backend: Qt5Agg
Populating the interactive namespace from numpy and matplotlib

In [2]:

    

import numpy as np


    

In [3]:

    

points = np.arange(-5, 5, .01)
xs, ys = np.meshgrid(points, points)
xs, ys


    

    
Out[3]:





(array([[-5.  , -4.99, -4.98, ...,  4.97,  4.98,  4.99],
        [-5.  , -4.99, -4.98, ...,  4.97,  4.98,  4.99],
        [-5.  , -4.99, -4.98, ...,  4.97,  4.98,  4.99],
        ..., 
        [-5.  , -4.99, -4.98, ...,  4.97,  4.98,  4.99],
        [-5.  , -4.99, -4.98, ...,  4.97,  4.98,  4.99],
        [-5.  , -4.99, -4.98, ...,  4.97,  4.98,  4.99]]),
 array([[-5.  , -5.  , -5.  , ..., -5.  , -5.  , -5.  ],
        [-4.99, -4.99, -4.99, ..., -4.99, -4.99, -4.99],
        [-4.98, -4.98, -4.98, ..., -4.98, -4.98, -4.98],
        ..., 
        [ 4.97,  4.97,  4.97, ...,  4.97,  4.97,  4.97],
        [ 4.98,  4.98,  4.98, ...,  4.98,  4.98,  4.98],
        [ 4.99,  4.99,  4.99, ...,  4.99,  4.99,  4.99]]))

In [4]:

    

import matplotlib.pyplot as plt


    

In [5]:

    

z = np.sqrt(xs**2 + ys**2)
z


    

    
Out[5]:





array([[ 7.07106781,  7.06400028,  7.05693985, ...,  7.04988652,
         7.05693985,  7.06400028],
       [ 7.06400028,  7.05692568,  7.04985815, ...,  7.04279774,
         7.04985815,  7.05692568],
       [ 7.05693985,  7.04985815,  7.04278354, ...,  7.03571603,
         7.04278354,  7.04985815],
       ..., 
       [ 7.04988652,  7.04279774,  7.03571603, ...,  7.0286414 ,
         7.03571603,  7.04279774],
       [ 7.05693985,  7.04985815,  7.04278354, ...,  7.03571603,
         7.04278354,  7.04985815],
       [ 7.06400028,  7.05692568,  7.04985815, ...,  7.04279774,
         7.04985815,  7.05692568]])

In [6]:

    

plt.imshow(z, cmap=plt.cm.gray)
plt.colorbar()
plt.title('Image plot of $\sqrt{x^2 + y^2}$ for a grid of values')


    

    
Out[6]:





<matplotlib.text.Text at 0x7fb7fc07aef0>