[Numpy-discussion] beginner question: rank-1 arrays

Stefan van der Walt stefan@sun.ac...
Mon Oct 8 17:15:46 CDT 2007


On Mon, Oct 08, 2007 at 11:00:39PM +0100, Robin wrote:
> Hi,
> 
> I am trying to implement a project in scipy. I think I am getting somewhere
> finally.
> 
> However in my code (I am converting from MATLAB) it is important to maintain 2d
> arrays, and keep the difference between row and column vectors. After working
> through some initial problems I think I am getting more of a picture of how
> things work in numpy.
> 
> However I am finding my code littered with things like:
> np.array(np.r_[0:nterms],ndmin=2)    (for a row vector)
> or
> np.array(np.r_[0:nterms],ndmin=2).T (for a column vector)

You can use

N.arange(10).reshape(-1,1)

or

N.c_[:10,]

But if you use this sort of thing often, just write your own factory
method:

def col(n):
    return N.arange(n).reshape(-1,1)

Cheers
Stéfan


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