🚀 go-pugleaf

The following is a miniscule problem I occasionally give to students to
warn them off using nested for-loops in S at just about any cost.

Problem: A random 2x2 matrix has the form
				  _    _
			A  =	 | a  b |
				 | c  d |
				  -    -
	where a,b,c and d are independent uniform random digits, i.e. in
	the set 0,1,...,9.  Using an enumerative method in S find the
	exact distribution of det(A) and plot it as a "high density" plot.

The literalist solution using four for-loops is utterly impractical.  The
most swish solution I have come up with uses no explicit loops, has only
four statements, and works in practically no time, but it does not make use
of the fact that the resuting distribution will clearly be symmetric about 0.
I would be interested to see if anyone can find a more effective solution.

[BTW It's no accident I slipped a "c" into the problem as a variable...]
-- 
Bill Venables, Dept. of Statistics, | Email: venables@stats.adelaide.edu.au
Univ. of Adelaide, South Australia. | Tel: +61 8 228 5412  Fax: ...232 5670