[SciPy-user] do complex numbers default to double precision?
pajer at iname.com
Thu Jun 30 07:00:02 CDT 2005
Ryan Krauss wrote:
> I have a matrix that is a function of a complex valued input. I am
> trying to find that value of that input that drives the determinant of
> the matrix to zero. I am searching for this value using fmin. The
> error I am trying to minimize is the abs(det(complex matrix)). I
> don't seem to be able to drive this error lower that roughly 9e-17,
> regardless of the values for ftol and xtol I use.
Many years ago I did some programing in "pure" Forth, which does not
support floating point numbers. That's right: integers only. I learned
something about the limitations of floating point numbers, and something
else about restructuring problems. I'm not suggesting you switch to
integer arithmetic. Your question just rang a bell in my head. Maybe
there is some other way to formulate your problem so that you don't run
up against floating point limitations. Who hasn't gotten bitten by
blind reliance on floating point arithmetic?
just a thought,
> Am I hitting some internal limitation? Are complex values by default
> single or double precision?
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