pyplot: loglog() with base e

Question

Python (and matplotlib) newbie here coming over from R, so I hope this question is not too idiotic. I'm trying to make a loglog plot on a natural log scale. But after some googling I cannot somehow figure out how to force pyplot to use a base e scale on the axes. The code I have currently:

import matplotlib.pyplot as pyplot 
import math

e = math.exp(1)
pyplot.loglog(range(1,len(degrees)+1),degrees,'o',basex=e,basey=e)

Where degrees is a vector of counts at each value of range(1,len(degrees)+1). For some reason when I run this code, pyplot keeps giving me a plot with powers of 2 on the axes. I feel like this ought to be easy, but I'm stumped...

Any advice is greatly appreciated!

Answer 1

When plotting using plt.loglog you can pass the keyword arguments basex and basey as shown below.

From numpy you can get the e constant with numpy.e (or np.e if you import numpy as np)

import numpy as np
import matplotlib.pyplot as plt

# Generate some data.
x = np.linspace(0, 2, 1000)
y = x**np.e

plt.loglog(x,y, basex=np.e, basey=np.e)
plt.show()

Edit

Additionally if you want pretty looking ticks you can use matplotlib.ticker to choose the format of your ticks, an example of which is given below.

import numpy as np

import matplotlib.pyplot as plt
import matplotlib.ticker as mtick

x = np.linspace(1, 4, 1000)

y = x**3

fig, ax = plt.subplots()

ax.loglog(x,y, basex=np.e, basey=np.e)

def ticks(y, pos):
    return r'$e^{:.0f}$'.format(np.log(y))

ax.xaxis.set_major_formatter(mtick.FuncFormatter(ticks))
ax.yaxis.set_major_formatter(mtick.FuncFormatter(ticks))

plt.show()