# [racket] matrix-solve and approximation errors

Interesting; even more when using rounded numbers returns a correct
solution!
To protect against such errors, maybe `matrix-solve` could run a post-check
to verify that M×X=B up to some epsilon, depending on an optional argument?
Or maybe just mention to do this check systematically in the docs?
On Wed, Apr 16, 2014 at 1:31 PM, Jens Axel Søgaard <jensaxel at soegaard.net>wrote:
>* 2014-04-16 12:18 GMT+02:00 Jens Axel Søgaard <jensaxel at soegaard.net>:
*>* > Hi Laurent,
*>* >
*>* > I think the underlying problem is that the matrix is *very* close to
*>* > an invertible one:
*>*
*>* non-invertible
*>*
*>*
*>* >> (matrix-determinant
*>* > (matrix [[ 1 0 9/10 1]
*>* > [ 0 1 1/10 1]
*>* > [ 9/10 1/10 82/100 1]
*>* > [ 1 1 1 0]]))
*>* > 0
*>*
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