### Drawing circles using matplotlib

Use the pylab.Circle command

import pylab #Imports matplotlib and a host of other useful modules
cir1 = pylab.Circle((0,0), radius=0.75,  fc='y') #Creates a patch that looks like a circle (fc= face color)
cir2 = pylab.Circle((.5,.5), radius=0.25, alpha =.2, fc='b') #Repeat (alpha=.2 means make it very translucent)
ax = pylab.axes(aspect=1) #Creates empty axes (aspect=1 means scale things so that circles look like circles)
ax.add_patch(cir1) #Grab the current axes, add the patch to it
pylab.show()


1. Thanks. I am new to Python, and just used your code. It works, and is useful.

As a suggestion, would you think about adding comments to explain the code. It would be very helpful to beginners like me.

1. Thanks! Finally did it.

2. This was of use! Thanks.

### Python: Multiprocessing: passing multiple arguments to a function

Write a wrapper function to unpack the arguments before calling the real function. Lambda won't work, for some strange un-Pythonic reason.

import multiprocessing as mp def myfun(a,b): print a + b def mf_wrap(args): return myfun(*args) p = mp.Pool(4) fl = [(a,b) for a in range(3) for b in range(2)] #mf_wrap = lambda args: myfun(*args) -> this sucker, though more pythonic and compact, won't work p.map(mf_wrap, fl)

### Flowing text in inkscape (Poster making)

You can flow text into arbitrary shapes in inkscape. (From a hint here).

You simply create a text box, type your text into it, create a frame with some drawing tool, select both the text box and the frame (click and shift) and then go to text->flow into frame.

UPDATE:

The omnipresent anonymous asked:
Trying to enter sentence so that text forms the number three...any ideas?
The solution:
Type '3' using the text toolConvert to path using object->pathSize as necessaryRemove fillUngroupType in actual text in new text boxSelect the text and the '3' pathFlow the text

### Latex math: Vertical bar

Like that used for indicating the evaluation of integrals between limits:

\bigg|

as in

\frac{\rho}{4\pi}\left(-\frac{1}{r}\right)\bigg|_{r_{0}}^{\infty}

from a hint here from robphy