[plt-scheme] random walk

On May 29, 2009, at 11:08 AM, Marijn Schouten (hkBst) wrote:

> I'm trying to write a macro that writes a function that sums the L2- 
> lengths of
> all (random) walks of depth d on a square grid of dimension DIM.

I just wrote a FUNCTION to do this, with no macros involved, in  
Intermediate+Lambda language, and (not counting test cases) it came  
to about twenty lines shorter than the attempt at a macro.  It's  
probably less run-time-efficient, but this problem is inherently  
exponential in the depth anyway, so I'm not convinced that moving  
part of it to compile-time will have much effect on the run time.

Oh, and my "function" is actually five functions, each short enough  
to comprehend and test.

Stephen Bloch
sbloch at adelphi.edu