I will answer this question too, because I feel like Keith. On Tue, Apr 29, 2008 at 02:21:34PM -0400, Alan G Isaac wrote: > On Tue, 29 Apr 2008, Keith Goodman apparently wrote: > > I often use x[i,:] and x[:,i] where x is a matrix and i is > > a scalar. I hope this continues to return a matrix.
> 1. Could you give an example of the circumstances of this > use? x[i, :]*A*x[:, i] I find this cleaner, because more explicit, than x[i]*A*x[:, i]. I'd be _very very_ upset if this broke. Breaking the explicit for the implicit is a _bad_ idea, and if you go down this path you go down the path of inconsistency. > 2. Would any or all of the following be just as good > a result? > a. 1d matrix Yes. > b. row and column vectors (1d but "oriented" for > linear algebra purposes) Yes. > 3. If 2a. and 2b. are no good for you, > a. would e.g. ``x[i:i+1,:]`` be too burdensome? No way. This is hard to read and the best way to make long calculations impossible to follow and debug. > b. would ``rows`` and ``columns`` attributes that > yielded matrics be an offsetting convenience? Hum, I don't love this because it introduces noise in the formulas, but at least it is explicit and readable. I would really like us to go down the way of the row/vector columns. This is consistent at least. Gaël _______________________________________________ Numpy-discussion mailing list Numpy-discussion@scipy.org http://projects.scipy.org/mailman/listinfo/numpy-discussion
