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sa6113 wrote:
> Dear All,
> 
> I have a problem using polyfit with a degree greater than 118 :

The problem is that polynomial fitting generally doesn't make sense for 
degree higher than 4 or 5--if that--and at very high degree it is 
inevitable that the matrix will become singular. In other words, there 
is not enough information in the data to uniquely determine the fit. 
Whatever it is you are trying to to, fitting a polynomial with a high 
degree is the wrong way to do it.

Eric

> 
> The code is :
> matplotlib.mlab.polyfit(  x,  y,  pow ) # pow is degree of polynomial
> 
> for pow in range 118 and  238 the error is :
> LinAlgError, 'singular martix'
> 
> and for pow greater than 237 this error raise :
> OverflowError : math range error

Christopher Brown wrote:
> With mpl 0.91.2, the markeredgewidth property does not seem to have an 
> effect when using the pdf backend (seems to always be 1, regardless of 
> what I set it to, and it seems to be fine with other backends). Here is 
> a minimal example:

Interestingly, the error only shows up in the pdf viewer foxit (what I 
happened to be using at the time). Other viewers display the markers 
properly. Although it is still unclear to me whether it is an 
mpl/pdf-backend error or a foxit rendering error.

Sorry to trouble you all.

On Sat, May 3, 2008 at 3:11 AM, sa6113 <s.p...@gm...> wrote:
>
>  Dear All,
>
>  I have a problem using polyfit with a degree greater than 118 :
>
>  The code is :
>  matplotlib.mlab.polyfit(  x,  y,  pow ) # pow is degree of polynomial
>
>  for pow in range 118 and  238 the error is :
>  LinAlgError, 'singular martix'
>
>  and for pow greater than 237 this error raise :
>  OverflowError : math range error

matplotlib.mlab.polyfit is deprecated (and is a thin wrapper to
numpy.polyfit in the current implementation).  Please direct polyfit
questions and problems to the numpy list.

JDH

Dear All,

I have a problem using polyfit with a degree greater than 118 :

The code is :
matplotlib.mlab.polyfit(  x,  y,  pow ) # pow is degree of polynomial

for pow in range 118 and  238 the error is :
LinAlgError, 'singular martix'

and for pow greater than 237 this error raise :
OverflowError : math range error
-- 
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