Joey K Tuttle wrote:
> On my G5 iMac -
>
>     x=: 1000 1000 [EMAIL PROTECTED] 0         NB. random real matrix
>     6!:2 'y=: %. x'             NB. invert it
> 13.7781
>
>     >./|, (=i.1000) - x +/ .* y  NB. how accurate?
> 1.97126e_13
>

Random matrices tend to be numerically stable.  Unstable ones crop up all
the time.

   hilbert=:]\ %@(i.&.<:@+:)
   x=:hilbert 10
   y=:%.x
   >./|, (=i.10) - x +/ .* y
0.108042

Best wishes,

John

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