strange array size problem

[chip9munk at gmail.com]

Interesting!
rank of the whole minus last row
numpy.linalg.matrix_rank(users_elements_matrix[:,0:42]) is 42

but also rank of whole is
numpy.linalg.matrix_rank(users_elements_matrix[:,0:43]) is 42

but what does that mean?!

could you explain briefly what now?

thank you!

On Friday, October 18, 2013 5:44:31 PM UTC+2, Oscar Benjamin wrote:
> On 18 October 2013 16:36,  <chip9munk at gmail.com> wrote:
> 
> > one more thing.
> 
> >
> 
> > the problem is not in the last column, if I use it in regression (only that column, or with a few others) I will get the results. But if I use all 43 columns python breaks!
> 
> 
> 
> Have you tried testing the rank with numpy.linalg.matrix_rank? I'm
> 
> guessing that the extra row makes the matrix singular (up to floating
> 
> point error).
> 
> 
> 
> 
> 
> Oscar