Re: multiplication yield strange results

"Gilles Rosselet" <gilles.rosselet@xxxxxxx> schreef in bericht
news:1160751505_29@xxxxxxxxxxxxxxxxxxx
Hello,

I call the following bit of code repeatedly during the execution of my
program:

Bx:= self.n[0].A*self.alpha[0].c + self.n[1].A*self.alpha[1].c +
self.n[2].A*self.alpha[2].c;
By:= -self.n[0].A*self.alpha[0].b - self.n[1].A*self.alpha[1].b -
self.n[2].A*self.alpha[2].b;
Bsqr:= Bx*Bx + By*By;

At first all goes well but suddenly Bx and By get extremly large (around
1E205) which turn Bsqr to INF.
Typical value before failure:
self.n[0].A -9.39E-7
self.n[1].A -9.45E-7
self.n[2].A -9.45E-7
self.alpha[0].c -30.08
self.alpha[1].c 62.99
self.alpha[2].c -32.90
self.alpha[0].b -30.08
self.alpha[1].b 62.99
self.alpha[2].b -57.07


This does not happen always at the same iteration, so I suspect the
problem could be something completely unrelated to this piece of code,
like an unitialized pointer.

Using memProof I have got a lot of error related to VirtuallAloc trying to
reference an invalid address. Could that be relevent?


As long as you have invalid pointer references an anlalysis of results will
be difficult. And we cannot help you since we can not reproduce the effects.
Locate and solve the pointer problems first!
Tom


.

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