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numpy/scipy polyfit precision

Posted on 2012-03-18
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I am trying to use numpy to perform a polyfit on a set of very large integers (~256bits).  The points for the line are generated by randomly assigning coefficients and then picking X values at random.  I then try to use numpy to recreate the polynomial from just those points, but the answer is not exact.  It is usually off by less than 10, but it shouldn't be.  Is there a way to turn up the precision for numpy?  matlab is able to crunch these numbers and come up with the exact polynomial, so I would expect numpy to be able to do the same.
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Question by:mattjp88
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defc0n1 earned 500 total points
ID: 37734769
As far as I know numpy does not support higher than double precision (float64).

Maybe mpmath can be useful for you.
They support real and complex numbers with arbitrary precision.

EDIT:

Forgot to mention there is also mlabwrap which gives you all of Matlab`s functionality in python.
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by:mattjp88
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Thanks for pointing out mpmath, it looks promising.

This was a small piece of a larger project, and fitting a polynomial ended up being only one method to get the answer we needed.  So we switched algorithms, so I wont be able to verify any other answers to this question.

the mention of mpmath and mlabwrap is enough to award points I think.
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