matplotlib node alignment and custom line style
<p>I'm plotting netowrk graphs (Water distribution networks) using bokeh and or matplotlib. From the reference software the  plots look like this:</p>

<p><img src="http://i.stack.imgur.com/8myGf.jpg" alt="Overview from EPAnet"></p>

<p>As you can see pumps and water towers have their own little symbols.
I'm using matplotlib and bokeh to plot the same graphs (with a little more info on the system state):</p>

<p><img src="http://i.stack.imgur.com/HQiew.png" alt="Current Bokeh plot"></p>

<p>As you can see we have squares and triangles as symbols now. So I would like to either add my own symbols based on some vector graphic of the symbols in the first plot, or at least rotate the triangles to be aligned with the arcs, such that they point along them. Any ideas on how to achieve either? I find the bokeh documentation rather confusing (as you can tell I'm a civil engineer not a programmer)</p>

<p>Instead of rotating the triangle, you may consider <a href="http://matplotlib.org/examples/pylab_examples/arrow_simple_demo.html" rel="nofollow">arrows</a>. 
If you really want to rotate the triangle, I normally rotate the three points of the triangle around its center (by rotation matrix). </p>

<p>About custom symbols, I have never import any external symbols into my matplotlib figure. I usually create the symbol as a polygon and then draw it using the <a href="http://matthiaseisen.com/pp/patterns/p0203/" rel="nofollow">polygon patches</a>.</p>

<p>Hope it helps.</p>

python matplotlib plot bokeh