There is a calculus book in pdf form online at djm.cc. I found this in my search for a reference to Netwton's difference quotient method [wikipedia], which I use in a paper and which Jeff wanted me to put in a reference for.

Looking for a reference to Netwton's difference quotient method was instructive because it led me to a problem I had not had to deal with yet: if you have a numerical method for computing a function f(x) then the simple newton's difference quotient method

d f(x) f(x+h) - f(x)
------ = --------------
dx h

is problematic because for small values of h (as required by the method) f(x+h) is almost the same as f(x) and the difference and the division may lead you into rounding errors.

### 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: