Re: Inverse Matrix Function appears a bit wonky

[Przemek Klosowski]

    For 2x2 matrices made up of integers between -3 and +3, the answer is
    obviously 14.4%. If you can't see that at first sight, try running the
    attached script. Sheesh!

 Very good! but, people don't use negative numbers when they pull the
 random matrices out of their... mental random number generator. When
 you use apos=2*rand(k,k)*maxval (which is equivalent to your a
 plus a constant matrix ones(k,k)*maxval, the probability drops by
 a factor of two, to 7%. Is there a simple explanation of that?

 OK, the official results are in: 3x3 {0..9}-valued matrices it's 4%, and
 2% for 4x4 matrices, and .5% for 5x5 matrices. Funny. The originator
 of this thread had 1-in-60 chance of picking a singular matrix.



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