Re: strange problem

[Laurent Jacques]

On Friday 28 November 2003 00:03, Geraint Paul Bevan wrote:
| The number -2.0817e-17 is -0.000000000000000020817, which is very, very
| close to zero. The error is due to the way that numbers are represented
| in computers.

Of course but I think that the question was:

Why the top-left entry of 
        [1,100;0,1]*[1,0;(-1/100),1] 
is 
        -2.0817e-17
while octave returns the true 0 if you enter
        1 + (100*-1/100)

Does Octave perform some LU decomposing of matrix to realize matrix 
multiplication ? 
This could explain the difference between the two results.

Laurent.



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