How to change alignment of displayed equations in IPython Notebook?

Question

I would like my MathJax displayed equations in IPython Notebook to be aligned at the left instead of centered. This is controlled by a core configuration option displayAlign in MathJax as described here.

I have tried to set this option in IPython Notebook by adding this to my config.js file

MathJax.Hub.Config({      displayAlign: "left" }); 

but it doesn't have any effect.

How can I set MathJax core configuration options in IPython Notebook?

[Update] I have found one way that works: add the above configuration lines not to config.js but to mathjaxutils.js. In my case (Windows 8) this file is found here: C:\Anaconda\Lib\site-packages\IPython\html\static\notebook\js\mathjaxutils‌​.js. This is not a great solution though because it involves modifying a file that will presumably get overwritten the next time I update IPython.

[Update] The technique suggested by @Ian in the comments does work, but just one notebook at a time. To summarize, I created a file my_css.css whose content is

<script>     MathJax.Hub.Config({         displayAlign: 'left'     }); </script> 

In the notebook, if I run this cell

from IPython.core.display import HTML css_file = 'my_css.css' HTML(open(css_file, "r").read()) 

displayed equations do get left aligned, as desired.

However, I would like this to be the default for all my notebooks. I tried adding this to my custom.js

MathJax.Hub.Config({     displayAlign: 'left' }); 

and for good measure added this to my custom.css

<script>     MathJax.Hub.Config({         displayAlign: 'left'     }); </script> 

But neither has any effect. If there is a way to make this setting a default for all notebooks without modifying the core IPython files, that would be perfect.

Answer 1

Use \begin{align} and \end{align}. This does not exactly answer the question but it has the desired effect. For example try:

$ \begin{align} \frac{1}{2} \times \frac{3}{2} = \frac{3}{4} \end{align} $ 

The above renders exactly the same as,

$$ \frac{1}{2} \times \frac{3}{2} = \frac{3}{4} $$ 

except that it is left justified.

This approach has the added advantage that other alignments can be be added, as in:

$ \begin{align} \dot{x} & = \sigma(y-x) \\ \dot{y} & = \rho x - y - xz \\ \dot{z} & = -\beta z + xy \end{align} $ 

This last code block is from Motivating Examples in the Jupyter Notebook docs.

Other examples of aligning equations can be found here Aligning several equations

Answer 2

In Jupyter lab, I find that using a single $ left aligns, whereas double $ centers the equations

$ \begin{align} c & = (0,\mu)+(a,b)\\ & =(a, b+\mu) \end{align} $ 

is left aligned whereas

$$ \begin{align} c & = (0,\mu)+(a,b)\\ & =(a, b+\mu) \end{align} $$ 

is centered