[Numpy-discussion] array(1) not fortran contiguous?

2007-07-20 Thread Lisandro Dalcin
Is the following inteded? Why array(1) is not fortran contiguous? In [1]: from numpy import * In [2]: __version__ Out[2]: '1.0.3' In [3]: array(1).flags Out[3]: C_CONTIGUOUS : True F_CONTIGUOUS : False OWNDATA : True WRITEABLE : True ALIGNED : True UPDATEIFCOPY : False -- Lisandro

Re: [Numpy-discussion] expm

2007-07-20 Thread Timothy Hochberg
On 7/20/07, Kevin Jacobs <[EMAIL PROTECTED]> <[EMAIL PROTECTED]> wrote: On 7/20/07, Kevin Jacobs <[EMAIL PROTECTED]> <[EMAIL PROTECTED]> wrote: > > On 7/20/07, Charles R Harris < [EMAIL PROTECTED]> wrote: > > > > I expect using sqrt(x) will be faster than x**.5. > > > > I did test this at one po

Re: [Numpy-discussion] expm

2007-07-20 Thread Kevin Jacobs <[EMAIL PROTECTED]>
On 7/20/07, Kevin Jacobs <[EMAIL PROTECTED]> <[EMAIL PROTECTED]> wrote: On 7/20/07, Charles R Harris <[EMAIL PROTECTED]> wrote: > > I expect using sqrt(x) will be faster than x**.5. > I did test this at one point and was also surprised that sqrt(x) seemed slower than **.5. However I found out

Re: [Numpy-discussion] expm

2007-07-20 Thread Kevin Jacobs <[EMAIL PROTECTED]>
On 7/20/07, Charles R Harris <[EMAIL PROTECTED]> wrote: I expect using sqrt(x) will be faster than x**.5. I did test this at one point and was also surprised that sqrt(x) seemed slower than **.5. However I found out otherwise while preparing a timeit script to demonstrate this observation.

Re: [Numpy-discussion] expm

2007-07-20 Thread Timothy Hochberg
On 7/20/07, Charles R Harris <[EMAIL PROTECTED]> wrote: [SNIP] I expect using sqrt(x) will be faster than x**.5. You might want to check that. I believe that x**0.5 is one of the magic special cases that is optimized to run fast (by calling sqrt in this case). IIRC the full set is [-1, 0, 0

Re: [Numpy-discussion] expm

2007-07-20 Thread Charles R Harris
On 7/20/07, Kevin Jacobs <[EMAIL PROTECTED]> <[EMAIL PROTECTED]> wrote: On 7/20/07, Anne Archibald <[EMAIL PROTECTED]> wrote: > > On 20/07/07, Nils Wagner <[EMAIL PROTECTED]> wrote: > > lorenzo bolla wrote: > > > hi all. > > > is there a function in numpy to compute the exp of a matrix, similar

Re: [Numpy-discussion] expm

2007-07-20 Thread Kevin Jacobs <[EMAIL PROTECTED]>
On 7/20/07, Nils Wagner <[EMAIL PROTECTED]> wrote: Your sqrtm_eig(x) function won't work if x is defective. See test_defective.py for details. I've added several defective matrices to my test cases and the SVD method doesn't work well as I'd thought (which is obvious in retrospect). I'm goi

Re: [Numpy-discussion] expm

2007-07-20 Thread Nils Wagner
On Fri, 20 Jul 2007 14:45:43 -0400 "Kevin Jacobs <[EMAIL PROTECTED]>" <[EMAIL PROTECTED]> wrote: > On 7/20/07, Nils Wagner <[EMAIL PROTECTED]> >wrote: >> >> Your sqrtm_eig(x) function won't work if x is defective. >> See test_defective.py for details. > > > I am aware, though at least on my s

Re: [Numpy-discussion] expm

2007-07-20 Thread Kevin Jacobs <[EMAIL PROTECTED]>
On 7/20/07, Nils Wagner <[EMAIL PROTECTED]> wrote: Your sqrtm_eig(x) function won't work if x is defective. See test_defective.py for details. I am aware, though at least on my system, the SVD-based method is by far the fastest and robust (and can be made more robust by the addition of a rela

Re: [Numpy-discussion] Pickle, pytables, and sqlite - loading and saving recarray's

2007-07-20 Thread Francesc Altet
A Divendres 20 Juliol 2007 20:16, Christopher Barker escrigué: > Another small note: > > I'm pretty sure sqlite stores everything as strings. This just plain has > to be slower than storing the raw binary representation (and may mean > for slight differences in fp values on the round-trip). HDF is

Re: [Numpy-discussion] Pickle, pytables, and sqlite - loading and saving recarray's

2007-07-20 Thread Christopher Barker
Another small note: I'm pretty sure sqlite stores everything as strings. This just plain has to be slower than storing the raw binary representation (and may mean for slight differences in fp values on the round-trip). HDF is designed for this sort of thing, sqlite is not. -Chris -- Chris

Re: [Numpy-discussion] expm

2007-07-20 Thread Nils Wagner
On Fri, 20 Jul 2007 13:03:09 -0400 "Kevin Jacobs <[EMAIL PROTECTED]>" <[EMAIL PROTECTED]> wrote: On 7/20/07, Anne Archibald <[EMAIL PROTECTED]> wrote: On 20/07/07, Nils Wagner <[EMAIL PROTECTED]> wrote: > lorenzo bolla wrote: > > hi all. > > is there a function in numpy to compute the exp o

Re: [Numpy-discussion] expm

2007-07-20 Thread Kevin Jacobs <[EMAIL PROTECTED]>
On 7/20/07, Anne Archibald <[EMAIL PROTECTED]> wrote: On 20/07/07, Nils Wagner <[EMAIL PROTECTED]> wrote: > lorenzo bolla wrote: > > hi all. > > is there a function in numpy to compute the exp of a matrix, similar > > to expm in matlab? > > for example: > > expm([[0,0],[0,0]]) = eye(2) > Numpy d

Re: [Numpy-discussion] expm

2007-07-20 Thread Anne Archibald
On 20/07/07, Nils Wagner <[EMAIL PROTECTED]> wrote: > lorenzo bolla wrote: > > hi all. > > is there a function in numpy to compute the exp of a matrix, similar > > to expm in matlab? > > for example: > > expm([[0,0],[0,0]]) = eye(2) > Numpy doesn't provide expm but scipy does. > >>> from scipy.lina

Re: [Numpy-discussion] Pickle, pytables, and sqlite - loading and saving recarray's

2007-07-20 Thread Francesc Altet
Vincent, A Divendres 20 Juliol 2007 15:35, Vincent Nijs escrigué: > Still curious however ... does no one on this list use (and like) sqlite? First of all, while I'm not a heavy user of relational databases, I've used them as references for benchmarking purposes. Hence, based on my own benchma

Re: [Numpy-discussion] Wrong lapack version detection (32/64bits)

2007-07-20 Thread Xavier Gnata
Pearu Peterson wrote: > Xavier Gnata wrote: > > >> I just would like to be able to tell numpy to use liblapack.so instead >> of this non free libmkl_lapack32.so >> > > For that set the following environment variable when building numpy/scipy: > >export MKL=None > > Hth, > Pearu > ok

Re: [Numpy-discussion] Pickle, pytables, and sqlite - loading and saving recarray's

2007-07-20 Thread Gael Varoquaux
On Fri, Jul 20, 2007 at 08:35:51AM -0500, Vincent Nijs wrote: > Sounds very interesting! Would you mind sharing an example (with code if > possible) of how you organize your experimental data in pytables. I have > been thinking about how I might organize my data in pytables and would luv > to hear

Re: [Numpy-discussion] expm

2007-07-20 Thread Nils Wagner
lorenzo bolla wrote: > hi all. > is there a function in numpy to compute the exp of a matrix, similar > to expm in matlab? > for example: > expm([[0,0],[0,0]]) = eye(2) > > thanks, > lorenzo. > > > __

[Numpy-discussion] expm

2007-07-20 Thread lorenzo bolla
hi all. is there a function in numpy to compute the exp of a matrix, similar to expm in matlab? for example: expm([[0,0],[0,0]]) = eye(2) thanks, lorenzo. ___ Numpy-discussion mailing list Numpy-discussion@scipy.org http://projects.scipy.org/mailman/lis

Re: [Numpy-discussion] Pickle, pytables, and sqlite - loading and saving recarray's

2007-07-20 Thread Vincent Nijs
Thanks Francesc! That does work much better: -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= PyTables version: 2.0 HDF5 version: 1.6.5 NumPy version: 1.0.4.dev3852 Zlib version: 1.2.3 BZIP2 version: 1.0.2 (30-Dec-2001) Python version:2.5.1 (r251

Re: [Numpy-discussion] Pickle, pytables, and sqlite - loading and saving recarray's

2007-07-20 Thread Timothy Hochberg
On 7/20/07, Vincent Nijs <[EMAIL PROTECTED]> wrote: Gael, Sounds very interesting! Would you mind sharing an example (with code if possible) of how you organize your experimental data in pytables. I have been thinking about how I might organize my data in pytables and would luv to hear how an e

Re: [Numpy-discussion] Pickle, pytables, and sqlite - loading and saving recarray's

2007-07-20 Thread Vincent Nijs
Gael, Sounds very interesting! Would you mind sharing an example (with code if possible) of how you organize your experimental data in pytables. I have been thinking about how I might organize my data in pytables and would luv to hear how an experienced user does that. Given the speed differences

Re: [Numpy-discussion] Logical Selector

2007-07-20 Thread Geoffrey Zhu
>Hi, >Well maybe it is a bug on my box (thunderbird) but the topic of the thread is "-lmkl_lapack64 on i368 ??". >Nothing to do with "Logical Selector" ;) Should I post another mail about this topic? >Xavier >ps : I'm just sorry for the noise if it is a bug on my side. >-- Hi Xavier, I di

Re: [Numpy-discussion] Wrong lapack version detection (32/64bits)

2007-07-20 Thread Pearu Peterson
Xavier Gnata wrote: > > I just would like to be able to tell numpy to use liblapack.so instead > of this non free libmkl_lapack32.so For that set the following environment variable when building numpy/scipy: export MKL=None Hth, Pearu ___ Numpy

Re: [Numpy-discussion] Pickle, pytables, and sqlite - loading and saving recarray's

2007-07-20 Thread Francesc Altet
A Divendres 20 Juliol 2007 04:42, Vincent Nijs escrigué: > I am interesting in using sqlite (or pytables) to store data for scientific > research. I wrote the attached test program to save and load a simulated > 11x500,000 recarray. Average save and load times are given below (timeit > with 20 repe

Re: [Numpy-discussion] Wrong lapack version detection (32/64bits)

2007-07-20 Thread Xavier Gnata
>>> Hi, >>> >>> I'm trying to update numpy by compiling the up to date svn: >>> >>> I get this error : >>> gcc: numpy/linalg/lapack_litemodule.c >>> gcc -pthread -shared >>> build/temp.linux-i686-2.4/numpy/linalg/lapack_litemodule.o >>> -lmkl_lapack32 -lmkl_lapack64 -lmkl -lvml -lguide -lpthread

Re: [Numpy-discussion] Pickle, pytables, and sqlite - loading and saving recarray's

2007-07-20 Thread Ivan Vilata i Balaguer
Gael Varoquaux (el 2007-07-20 a les 11:24:34 +0200) va dir:: > I new I really should put these things on line, I have just been wanting > to iron them a bit, but it has been almost two year since I have touched > these, so ... > > http://scipy.org/Cookbook/hdf5_in_Matlab Wow, that looks really s

Re: [Numpy-discussion] Pickle, pytables, and sqlite - loading and saving recarray's

2007-07-20 Thread Gael Varoquaux
On Fri, Jul 20, 2007 at 01:59:13AM -0700, Andrew Straw wrote: > I want that Matlab script! I new I really should put these things on line, I have just been wanting to iron them a bit, but it has been almost two year since I have touched these, so ... http://scipy.org/Cookbook/hdf5_in_Matlab Fee

Re: [Numpy-discussion] Pickle, pytables, and sqlite - loading and saving recarray's

2007-07-20 Thread Andrew Straw
Gael Varoquaux wrote: > On Thu, Jul 19, 2007 at 09:42:42PM -0500, Vincent Nijs wrote: >>I'd luv to hear from people using sqlite, pytables, and cPickle about >>their experiences. > > I was about to point you to this discussion: > http://projects.scipy.org/pipermail/scipy-user/2007-April/01