Konrad Hinsen wrote: > On 22.02.2008, at 01:10, Alan G Isaac wrote: > > >> Someone once pointed out on this list that one might >> consider a matrix to be a container of 1d vectors. For NumPy, >> however, it is natural that it be a container of 1d arrays. >> (See the discussion for the distinction.) >> > > If I were to design a Pythonic implementation of the mathematical > concept of a matrix, I'd implement three classes: Matrix, > ColumnVector, and RowVector. It would work like this: > > m = Matrix([[1, 2], [3, 4]]) > > m[0, :] --> ColumnVector([1, 3]) > m[:, 0] --> RowVector([1, 2]) > These seem backward to me. I would think that m[0,:] would be the RowVector([1,2]) and m[:,0] be the ColumnVector([1,3]). > m[0,0] --> 1 # scalar > > m.shape --> (2, 2) > m[0].shape --> (2,) > What is m[0] in this case? The same as m[0, :]? > However, the matrix implementation in Numeric was inspired by Matlab, > where everything is a matrix. But as I said before, Python is not > Matlab. It should be kept in mind, however, that Matlab's matrix object is used successfully by a lot of people and should not be dismissed as irrelevant.
I would like to see an improved Matrix object as a built-in type (for 1.1). I am aware of two implementations that could be referred to in creating it: CVXOPT's matrix object and NumPy's matrix object. There may be others as well. If somebody has strong feelings about this sufficient to write a matrix built-in, then the door is wide open. Best, -Travis _______________________________________________ Numpy-discussion mailing list Numpy-discussion@scipy.org http://projects.scipy.org/mailman/listinfo/numpy-discussion
