[Numpy-discussion] fixing diag() for matrices

Christopher Barker Chris.Barker at noaa.gov
Fri Jul 28 11:43:44 CDT 2006

Keith Goodman wrote:
> diag(NxN matrix) should return a Nx1 matrix
> diag(Nx1 or 1xN matrix) should return a NxN matrix

This is the key problem: extracting the diagonal of a matrix and 
creating a matrix from a diagonal are two different operations: 
overloading one function to do both was a bad idea to begin with.

Maybe we should just keep diag() as is is for backward compatibility 
(deprecated), and make:

get_diag() and make_diag() instead.

Then it would be unambiguous what you wanted with:


You can call them something else, but you get the idea.


Christopher Barker, Ph.D.
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Chris.Barker at noaa.gov

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