Matplotlib raw latex "\epsilon" only yields "\varepsilon"

Question

I'm using Matplotlib to analyze results & generate figures. I need Greek symbols in the legend and axis labels, including $\epsilon$. However, the resulting text doesn't distinguish between "normal" \epsilon and \varepsilon --- both of them appear as \varepsilon. Here's a minimal example: ``` import numpy as np from pylab import * import matplotlib.pyplot as plt t = np.arange(0.0, 1.0 + 0.01, 0.01) s = np.cos(4 * np.pi * t) + 2 fig = plt.figure() ax = fig.add_subplot(1,1,1) ax.plot(t, s, 'k-', linewidth=2.0, label=r'$\epsilon$, $\varepsilon$, $\phi$, $\varphi$, $\sigma$, $\varsigma$') plt.title(r'$\epsilon$, $\varepsilon$, $\phi$, $\varphi$, $\sigma$, $\varsigma$') plt.xlabel(r'$t [M]$') plt.ylabel(r'$\epsilon$, $\varepsilon$, $\phi$, $\varphi$, $\sigma$, $\varsigma$') ax.legend(ncol=2, loc='lower left', fancybox=True) plt.show() ``` When I process this on my Macbook (OS X El Capitan with Macports installations of TexLive and py27-matplotlib), everything renders correctly except the \…

Accepted Answer

You are not using TeX in your script. Matplotlib provides what is called MathText, which is a subset of LaTeX commands, rendered in normal UTF8 characters. This is how MathText looks like with the default fontset:

You can change the fontset to have "\varepsilon" look different than "\epsilon". However, it seems that out of the available fontsets, only "cm" has actually different symbols for those commands.

```
plt.rcParams["mathtext.fontset"] = "cm"
```

This will produce:

In order to have Latex used to render your text, you need to specifically tell matplotlib to do so. One option is to use

```
plt.rcParams["text.usetex"] =True
```

at the beginning of your script. This requires a working TeX installation. The example would then look like this, where "\varepsilon" and "\epsilon" are indeed different.

Matplotlib raw latex "\epsilon" only yields "\varepsilon"

Solution

Problem