albmont at centroin.com.br
Thu Apr 19 15:24:25 CEST 2007
Ted Harding wrote:
> There are various ways round this, but a 'for' loop with
> a fixed number of iterations is not usully one of them!
> The simplest is to use while(). A possibly strategy is
> Y.old <- initial.Y
> Y <- compute.Y(Y.old, ...)
> if(abs(Y - Y.old) < small.number) break
> Y.old <- Y
> This will loop indefinitely until the convergence criterion
> abs(Y - Y.old) < small.number
> is met, and then stop.
I guess some precaution must be taken to prevent that the loop
Those algorithms that must optimize something, but run the risk
of running forever, sound like the "chess playing" engine: we
know that a deterministic solution exists (there is a finite number
of chess positions), but it's not practical to check all of them.
I read somewhere that computer loop problems are treated as if
the computer was "playing chess" agains Murphy: it tries hard to
solve the problem, but sometimes he must give up a path and backtrack
to a less optimum but faster solution.
Do I make any sense?
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