Mailman 3 November 2008 - SciPy-User

Re: [SciPy-user] Questions about Line Integral Convolution tutorial
by Bridgman, William T. 26 Nov '08

26 Nov '08

Anne & David, I've made some revisions to the lic_internal.pyx file. They seem to fix the problems I was having, but in the process, really alter your demo program output. My major changes are 1) clean up array indexing: w,x,i and h,y,j are correlated now 2) the reverse integration along the line seemed to start at the end of the line. I reinitialized it to kernellen//2 3) added comments I can package it up and stage it for you to review and update on the Wiki. Please email me directly on the location. Thanks. Tom -- Dr. William T."Tom" Bridgman Scientific Visualization Studio Global Science & Technology, Inc. NASA/Goddard Space Flight Center Email: William.T.Bridgman(a)nasa.gov Code 610.3 Phone: 301-286-1346 Greenbelt, MD 20771 FAX: 301-286-1634 http://svs.gsfc.nasa.gov/

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bvp install / import problem :again
by ozan bakis 25 Nov '08

25 Nov '08

Thank syou very much Mr. Kern, It works now... Ozan On Tue, Nov 25, 2008 at 12:21, ozan bakis <ozanbakis(a)gmail.com <http://projects.scipy.org/mailman/listinfo/scipy-user>> wrote: >* Hi again, *>* *>* I am trying to install and use the bvp package in scipy. I download *>* the source file in my home directory, then *>* *>* $ cd bvp-0.2.4 *>* $ sudo python setup.py build *>* $ sudo python setup.py install *>* *>* When I type (in python) *>>>>* import scipy.special *>>>>* import bvp *>* *>* Iget the following error message: *>* *>* Traceback (most recent call last): *>* File "<stdin>", line 1, in <module> *>* File "bvp/__init__.py", line 6, in <module> *>* import colnew *>* File "bvp/colnew.py", line 63, in <module> *>* import _colnew *>* ImportError: No module named _colnew * Change directories. Python looks in the current directory before site-packages, so you are picking up the unbuilt source files, not the installed files. -- Robert Kern

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bvp install / import problem :again
by ozan bakis 25 Nov '08

25 Nov '08

Hi again, I am trying to install and use the bvp package in scipy. I download the source file in my home directory, then $ cd bvp-0.2.4 $ sudo python setup.py build $ sudo python setup.py install When I type (in python) >>> import scipy.special >>> import bvp Iget the following error message: Traceback (most recent call last): File "<stdin>", line 1, in <module> File "bvp/__init__.py", line 6, in <module> import colnew File "bvp/colnew.py", line 63, in <module> import _colnew ImportError: No module named _colnew I use ubuntu 8.10 on a Dell inspiron. Thank you very much (especially Robert Kern for rapid answer), ozan Date: Mon, 24 Nov 2008 16:00:55 -0600 From: "Robert Kern" <robert.kern(a)gmail.com> Subject: Re: [SciPy-user] bvp import problem To: "SciPy Users List" <scipy-user(a)scipy.org> Message-ID: <3d375d730811241400w43a99174kb449eb40562f6ff1(a)mail.gmail.com> Content-Type: text/plain; charset=UTF-8 On Mon, Nov 24, 2008 at 15:57, ozan bakis <ozanbakis(a)gmail.com> wrote: > Hi all, > > I am very new to python and scipy. As an economist I am especially > interested in optimization > and differential equations tools of scipy. I have tried the some of the > online examples and have > been impressed by how easy userfriendly it is. Thank you for great work. > > I have tried to install bvp package as explained ot its web site by >>>> sudo python setup.py build > > I did not get any error. That's how to build it. Now, you need to install it. $ sudo python setup.py install Note that this, and the previous command, should be done at a terminal shell, not the Python prompt. > But when I want to import bvp I get the following: >>>> import scipy as N >>>> N.pkgload('special') Don't use pkgload(). Just import scipy.special. -- Robert Kern "I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth." -- Umberto Eco

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Re: [SciPy-user] Questions about Line Integral Convolution tutorial
by Bridgman, William T. 25 Nov '08

25 Nov '08

Anne, I've got a 3-D vector field that separates nicely into toroidal and a 2-D poloidal component. I plan to use LIC on the poloidal component projected on a slice of the volume. In the Cabral paper, Section 4.3 mentions a wrapping that can occur if the texture is too small. I'm wondering if the shift I'm seeing may be an artifact of the texture dimensions being transposed relative to the input vector field. If the texture doesn't have to be the same size as the vector field, it should be an easy fix to get around for now. Part of my dataset also has a parallel flow near the edge which this paper mentions can create false singularities. Thanks for the input. Tom On Nov 24, 2008, at 10:56 PM, scipy-user-request(a)scipy.org wrote: > 2008/11/24 Bridgman, William T. <William.T.Bridgman(a)nasa.gov>: > >> Is there any protocol for others updating the Wiki entry? I've just >> joined Scipy but been a member of AstroPy since its inception - but I >> have yet to write or update a Wiki page. > > Generally the protocol is "go right ahead, it's version-controlled". > Just out of curiosity, what were you hoping to use the LIC code for? > >> I'm still getting some type of 'shifting' of my dataset after running >> LIC, so I need to examine the Cabral reference more closely. I think >> I'm still missing something. > > It is totally possible there's a big in my code. In particular David > Huard pointed out there may be an indexing bug that means that instead > of integrating forward, it integraes backward twice. > > If the code works right, you shouldn't see any shifting, but Cabral et > al. point out that it's very important the algorithm and kernel be > symmetric, or you can get circles turning into spirals and the like. > > Anne -- Dr. William T."Tom" Bridgman Scientific Visualization Studio Global Science & Technology, Inc. NASA/Goddard Space Flight Center Email: William.T.Bridgman(a)nasa.gov Code 610.3 Phone: 301-286-1346 Greenbelt, MD 20771 FAX: 301-286-1634 http://svs.gsfc.nasa.gov/

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splines with extrapolation and derivatives
by dmitrey 25 Nov '08

25 Nov '08

hi all, I need Python splines soft (1-d, 2-d, 3-d preferably general n-d) that is capable to do extrapolation. Having derivatives in extrapolated points (df/dx, where x.ndim = n) is highly preferable. Are there any numpy / scipy / other Python tools capable of this? Thank you in advance, D.

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scikits samplerate
by Nils Wagner 25 Nov '08

25 Nov '08

Hi all, I tried to install samplerate via python setup.py install --prefix=$HOME/local --single-version-externally-managed --record=/dev/null samplerate_info: libraries samplerate not found in /data/home/nwagner/local Traceback (most recent call last): File "setup.py", line 161, in <module> 'Topic :: Scientific/Engineering'] File "/data/home/nwagner/local/lib/python2.5/site-packages/numpy/distutils/core.py", line 150, in setup config = configuration() File "setup.py", line 116, in configuration src_config = src_info.get_info() File "/data/home/nwagner/local/lib/python2.5/site-packages/numpy/distutils/system_info.py", line 410, in get_info self.calc_info() File "setup.py", line 73, in calc_info raise self.notfounderror() __main__.SamplerateNotFoundError: samplerate (http://www.mega-nerd.com/SRC/) library not found. Directories to search for the libraries can be specified in the site.cfg file (section [samplerate]). The libraries are located in /data/home/nwagner/local/lib/libsndfile.a /data/home/nwagner/local/lib/libsamplerate.a How do I set up a corresponding site.cfg ? Nils

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Debugging f2py-created modules
by Jose Luis Gomez Dans 25 Nov '08

25 Nov '08

Hi, I have an f2py created module that wraps some fortran into a Python object. When I run one of the methods, I get the following error: <type 'exceptions.ValueError'>: failed to initialize intent(inout) array -- expected elsize=4 but got 8 My method teakes some 34 or so parameters, and there are several defined as inout, so I don't really know where to start looking. Is there some option that tells me what bit of my calling sequence is causing the problem? Say my function call is (a, b, c, d) = my_mod.my_method ( x, y, z, inout_a, inout_b, inout_c) how do I know that the error is coming from inout_a, or inout_b? Or indeed somewhere else? In general, how do you debug a f2py module? Thanks J -- Psssst! Schon vom neuen GMX MultiMessenger gehört? Der kann`s mit allen: http://www.gmx.net/de/go/multimessenger

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[ Python(x,y) ] New release : 2.1.5
by Pierre Raybaut 24 Nov '08

24 Nov '08

Hi all, Release 2.1.5 is now available on http://www.pythonxy.com. (Full Edition, Basic Edition, Light Edition, Custom Edition and soon the update) Changes history Version 2.1.5 (11-24-2008) * Added: o QtHelp 4.4.1: complete Qt documentation (Qt, Qt Designer, ...) integrated to Qt Assistant * Updated: o console 2.0.141.3 o Notepad++ 5.1.0 o Cython 0.10 o IPython 0.9.1.4 o py2exe 0.6.9 o QtEclipse 1.4.1.2 o Sphinx 0.5 o wxPython 2.8.9.2 o xy 1.0.12 o Following updates are relevant only for a new install of Python(x,y) (there is absolutely no need to update your current install) o reportlab 2.2.1 o xydoc 1.0.1 o PyQt4 4.4.3.4 o Eclipse 3.4.1.1 * Corrected: o Issues 35, 36, 37, 38 and many other minor bug fixes Regards, Pierre Raybaut

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CorePy 1.0 Release (x86, Cell BE, BSD!)
by Chris Mueller 24 Nov '08

24 Nov '08

Hi scipy-ers - Some of you may remember CorePy from previous SciPy conferences. Feedback from those meetings was very helpful for planning the future of CorePy. Without further ado... Announcing CorePy 1.0 - http://www.corepy.org We are pleased to announce the latest release of CorePy. CorePy is a complete system for developing machine-level programs in Python. CorePy lets developers build and execute assembly-level programs interactively from the Python command prompt, embed them directly in Python applications, or export them to standard assembly languages. CorePy's straightforward APIs enable the creation of complex, high-performance applications that take advantage of processor features usually inaccessible from high-level scripting languages, such as multi-core execution and vector instruction sets (SSE, VMX, SPU). This version addresses the two most frequently asked questions about CorePy: 1) Does CorePy support x86 processors? Yes! CorePy now has extensive support for 32/64-bit x86 and SSE ISAs on Linux and OS X*. 2) Is CorePy Open Source? Yes! CorePy now uses the standard BSD license. Of course, CorePy still supports PowerPC and Cell BE SPU processors. In fact, for this release, the Cell run-time was redesigned from the ground up to remove the dependency on IBM's libspe and now uses the system-level interfaces to work directly with the SPUs (and, CorePy is still the most fun way to program the PS3). CorePy is written almost entirely in Python. Its run-time system does not rely on any external compilers or assemblers. If you have the need to write tight, fast code from Python, want to demystify machine-level code generation, or just miss the good-old days of assembly hacking, check out CorePy! And, if you don't believe us, here's our favorite user quote: "CorePy makes assembly fun again!" __credits__ = """ CorePy is developed by Chris Mueller, Andrew Friedley, and Ben Martin and is supported by the Open Systems Lab at Indiana University. Chris can be reached at cmueller[underscore]dev[at]yahoo[dot]com. """ __footnote__ = """ *Any volunteers for a Windows port? :) """

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bvp import problem
by ozan bakis 24 Nov '08

24 Nov '08

Hi all, I am very new to python and scipy. As an economist I am especially interested in optimization and differential equations tools of scipy. I have tried the some of the online examples and have been impressed by how easy userfriendly it is. Thank you for great work. I have tried to install bvp package as explained ot its web site by >>> sudo python setup.py build I did not get any error. But when I want to import bvp I get the following: >>> import scipy as N >>> N.pkgload('special') >>> import bvp Traceback (most recent call last): File "<stdin>", line 1, in <module> File "bvp/__init__.py", line 6, in <module> import colnew File "bvp/colnew.py", line 63, in <module> import _colnew ImportError: No module named _colnew Any idea? Thanks in advance, ozan

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