Mailman 3 September 2007 - SciPy-User

APL2007 - Arrays and Objects - Early Bird Registration and Preliminary Program
by Steven H. Rogers Sept. 14, 2007

Sept. 14, 2007

This is the last day for early bird registration for APL2007, 21-23 Oct in Montreal. It's co-located with OOPSLA2007 and sharing registration services at: http://www.regmaster.com/conf/oopsla2007.html =============== Preliminary Program =============== Tutorials and workshops ================= Introduction to APL (Ray Polivka) Object Oriented for APLers, APL for OOers (Dan Baronet) ... others in the works Presentations ========= No Experience Necessary: Hire for Aptitude - Train for Skills (Brooke Allen) Compiling APL with APEX (Robert Bernecky) APL, Bioinformatics, Cancer Research (Ken Fordyce) Generic Programming on Nesting Structure (Stephan Herhut, Sven-Bodo Scholz, Clemens Grelck) Interactive Array-Based Languages and Financial Research (Devon McCormick) Array vs Non-Array Approaches to Programming Problems (Devon McCormick) Design Issues in APL/OO Interfacing (Richard Nabavi) Arrays of Objects, or Arrays within Objects (Richard Nabavi) Competing, with J (John Randall) ... others in the works There is still room for oral or poster presentations that will not be contributed papers (published in a special issue of APL Quote Quad). If you would like to make an oral presentation or a poster, contact Lynne Shaw (Shaw(a)acm.org). ACM SIGAPL has broadened it's scope to all Array Programming Languages and NumPy/SciPy representation would be welcome.

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getting stats.zprob to return float96
by Martin Blom Sept. 13, 2007

Sept. 13, 2007

Hello everyone, I'm using stats.zprob and need some more decimal points than standard python floats can give me, and I need the function to be fast. Can I get the standard scipy zprob or ndtr to return float96 in some way? Or do I need to modify something in special/cephes or something like that? cheers Martin

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determinants
by Alastair Basden Sept. 13, 2007

Sept. 13, 2007

Hi, I wonder whether there is a bug in scipy.linalg.det? If I call this with my matrix, it returns inf. The matrix is 2048x2048 in size, with no inf elements (max 54, min -13), float64 type. I can't work out why it would think the determinant is infinity! Thanks...

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Problems with ACML
by Ryan May Sept. 13, 2007

Sept. 13, 2007

Hi, Does anyone here use the AMD Core Math Libraries (ACML) as their underlying libraries for BLAS/LAPACK/etc. in SciPy? I have problems with (at least) scipy.linalg.eigvals (Fernando discovered this at SciPy on my laptop). For instance, the following crashes reliably with ACML, but works fine with ATLAS versions of BLAS/LAPACK: >>>from scipy.linalg import eigvals >>>from numpy.random import rand >>>a = rand(100,100) >>>eigvals(a) Anyone else have this problem? Is ACML known to be a bad thing to use with SciPy? Thanks, Ryan -- Ryan May Graduate Research Assistant School of Meteorology University of Oklahoma

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fft of an image
by Emanuele Zattin Sept. 13, 2007

Sept. 13, 2007

hello, i would like to show the magnitude of the fourier transform of an image. interesting informations appear in the four corners of the resulting image, but i would like to shift the matrix in order to have the corners meeting each other in the middle. any hint? -- Emanuele Zattin --------------------------------------------------- -I don't have to know an answer. I don't feel frightened by not knowing things; by being lost in a mysterious universe without any purpose — which is the way it really is, as far as I can tell, possibly. It doesn't frighten me.- Richard Feynman

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Problem getting Full SciPy package set installed.
by Lou Pecora Sept. 13, 2007

Sept. 13, 2007

On Mac OSX 10.4.10, Python 2.4. I got NumPy 1.0.3.1 installed from the tarball successfully. I got gfortran installed (seemed successful) from the SourceForge Mac HPC page. But I had a serious error when I tried to install the latest SciPy package set (0.5.2.1) from the tarball. When I run the usual python setup.py install I get (after a LOT of output): ... Lib/integrate/quadpack/dqelg.f: In function 'dqelg': Lib/integrate/quadpack/dqelg.f:1: internal compiler error: Bus error Please submit a full bug report, with preprocessed source if appropriate. See <URL:http://gcc.gnu.org/bugs.html> for instructions. error: Command "/usr/local/bin/gfortran -Wall -ffixed-form -fno-second-underscore -fPIC -O3 -funroll-loops -c -c Lib/integrate/quadpack/dqelg.f -o build/temp.macosx-10.3-fat-2.4/Lib/integrate/quadpack/dqelg.o" failed with exit status 1 That error looks really low-level. How can I get the SciPy package installed? Is there another way? Thanks for any help. -- Lou Pecora, my views are my own. --------------- Great spirits have always encountered violent opposition from mediocre minds. -Albert Einstein ____________________________________________________________________________________ Building a website is a piece of cake. Yahoo! Small Business gives you all the tools to get online. http://smallbusiness.yahoo.com/webhosting

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Can't import SciPy packages
by Lou Pecora Sept. 13, 2007

Sept. 13, 2007

I have the SciPy library from Enthought, but I can't import the sub-packages (like integrate or special) in ipython. Here's what happens: import scipy.integrate --------------------------------------------------------------------------- exceptions.ImportError Traceback (most recent call last) /Users/loupecora/<ipython console> /Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site-packages/scipy/integrate/__init__.py 7 from info import __doc__ 8 ----> 9 from quadrature import * 10 from odepack import * 11 from quadpack import * /Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site-packages/scipy/integrate/quadrature.py 6 'cumtrapz'] 7 ----> 8 from scipy.special.orthogonal import p_roots 9 from numpy import sum, ones, add, diff, isinf, isscalar, \ 10 asarray, real, trapz, arange, empty /Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site-packages/scipy/special/__init__.py 6 #from special_version import special_version as __version__ 7 ----> 8 from basic import * 9 import specfun 10 import orthogonal /Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site-packages/scipy/special/basic.py 6 7 from numpy import * ----> 8 from _cephes import * 9 import types 10 import specfun ImportError: Inappropriate file type for dynamic loading I'm on a MacBook Pro, Tiger 10.4.10, python 2.4. Any ideas? Thanks. -- Lou Pecora, my views are my own. --------------- Great spirits have always encountered violent opposition from mediocre minds. -Albert Einstein ____________________________________________________________________________________ Got a little couch potato? Check out fun summer activities for kids. http://search.yahoo.com/search?fr=oni_on_mail&p=summer+activities+for+kids&…

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issues while loading scatter data file with load() from pylab...
by fred Sept. 13, 2007

Sept. 13, 2007

Hi all, First question. Using load() function from pylab, array returned is a float64. Is it possible to directly load it in float32 ? I don't need the double precision. And I saw nothing with load? The issue. My scatter data has ~7x1e6 points, stored as x, y, z, v per line. Using a short C code and fscanf, it takes 12 s and ~240 MB in format double to load it. Fine. Using load() from pylab to load this file is endless and need more than 1 GB. What's the problem ? TIA Cheers, -- http://scipy.org/FredericPetit

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really basic where() function question
by Michael Hearne Sept. 13, 2007

Sept. 13, 2007

I'm trying to put together a presentation at work on Python, and I'm confused about the where() numpy function. The documentation, which is scant, indicates that where() requires three input arguments: where(condition,x,y) returns an array shaped like condition and has elements of x and y where condition is respectively true or false First, I have to admit that I don't understand what x and y are for here. Second, I want to use where() like find() in Matlab - namely: a = array([3,5,7,9]) i = where(a <= 6) => should return (array([0, 1]),) (see http:// www.scipy.org/ Numpy_Example_List#head-7de97cb88f064612d2f339e9713a949cd7f2f804) instead, I get this error: ------------------------------------------------------------------------ --- <type 'exceptions.TypeError'> Traceback (most recent call last) /Users/mhearne/scipy/<ipython console> in <module>() <type 'exceptions.TypeError'>: where() takes exactly 3 arguments (1 given) What am I doing wrong? Or did the usage of where() change since the cookbook example was written? --Mike

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Python FEA
by Ryan Krauss Sept. 12, 2007

Sept. 12, 2007

I would like to start working on finite element analysis using Python. I would like to work specifically in two areas: 1. feedback control of flexible structures 2. modeling impact/contact My assumption is that much is being done in FEA in general and that I would need to write code specific to incorporating feedback or modeling contact. But I am not sure what all is being done using Python in FEA. A quick google search turned up the following: PyFemax: http://www.python.org/pycon/papers/pysparse.html Pfem: http://pfem.sourceforge.net/ which seem like good starts that may or may not still be maintained. Is anyone working on FEA in Python or can anyone point me to a project my google search failed to turn up? Thanks, Ryan

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