jseabold wrote: > > On Mon, Jun 8, 2009 at 3:33 PM, Robert Kern<robert.k...@gmail.com> wrote: >> On Mon, Jun 8, 2009 at 14:10, Alan G Isaac<ais...@american.edu> wrote: >>>>> Going back to Alan Isaac's example: >>>>> 1) beta = (X.T*X).I * X.T * Y >>>>> 2) beta = np.dot(np.dot(la.inv(np.dot(X.T,X)),X.T),Y) >>> >>> >>> Robert Kern wrote: >>>> 4) beta = la.lstsq(X, Y)[0] >>>> >>>> I really hate that example. > I propose the following alternative for discussion: U, s, Vh = np.linalg.svd(X, full_matrices=False) 1) beta = Vh.T*np.asmatrix(np.diag(1/s))*U.T*Y 2) beta = np.dot(Vh.T, np.dot(np.diag(1/s), np.dot(U.T, Y))) 1) is with X and Y starting out as matrices, 2) is with arrays. Even diag results in an array that has to be matricized. Sigh. -- View this message in context: http://www.nabble.com/matrix-default-to-column-vector--tp23652920p24023215.html Sent from the Numpy-discussion mailing list archive at Nabble.com. _______________________________________________ Numpy-discussion mailing list Numpy-discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
- Re: [Numpy-discussion] matrix default to column vecto... Olivier Verdier
- Re: [Numpy-discussion] matrix default to column vecto... Alan G Isaac
- Re: [Numpy-discussion] matrix default to column vecto... Tom K.
- Re: [Numpy-discussion] matrix default to column vecto... Olivier Verdier
- Re: [Numpy-discussion] matrix default to column vecto... Tom K.
- Re: [Numpy-discussion] matrix default to column vecto... Robert Kern
- Re: [Numpy-discussion] matrix default to column vecto... Tom K.
- Re: [Numpy-discussion] matrix default to column vecto... Alan G Isaac
- Re: [Numpy-discussion] matrix default to column vecto... Robert Kern
- Re: [Numpy-discussion] matrix default to column vecto... Skipper Seabold
- Re: [Numpy-discussion] matrix default to column vecto... Tom K.
- Re: [Numpy-discussion] matrix default to column vecto... Charles R Harris
- Re: [Numpy-discussion] matrix default to column vecto... Stéfan van der Walt
- Re: [Numpy-discussion] matrix default to column vecto... josef . pktd
- Re: [Numpy-discussion] matrix default to column vecto... Robert Kern
- Re: [Numpy-discussion] matrix default to column vecto... Alan G Isaac
- Re: [Numpy-discussion] matrix default to column vecto... Olivier Verdier
- Re: [Numpy-discussion] matrix default to column vecto... Charles R Harris
- Re: [Numpy-discussion] matrix default to column vecto... Alan G Isaac
- Re: [Numpy-discussion] matrix default to column vecto... Robert Kern
- Re: [Numpy-discussion] matrix default to column vecto... Charles R Harris