Mailman 3 January 2001 - NumPy-Discussion

simple array help?
by Pete Shinners 17 Sep '01

17 Sep '01

i have a simple array with floating values >>> print a array([ 0. , 0.2, 0.4, 0.6, 0.8]) what i need to do is change each index into another dimension with 3 indices. hmm, kind of confusing, an example will explain better >>> b = array(zip(a,a,a)) >>> print b array([[ 0. , 0. , 0. ], [ 0.2, 0.2, 0.2], [ 0.4, 0.4, 0.4], [ 0.6, 0.6, 0.6], [ 0.8, 0.8, 0.8]]) ok, this does the job, but once i start using large arrays, the back-n-forth conversion between arrays and python lists is costing me quite a bit. is there a way i can reshape the array this way without the call to python's 'zip'? (no, 'map' doesn't count either) i've tried much fooling with NewAxis, resize, and friends. but either i haven't stumbled upon the correct combination or i'm not trying the correct tools. i'd like to keep this as quick as possible, so hopefully it can be done without anything too elaborate. thanks (doh, sorry for the previous distutils related post... hit the wrong mailing list)

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Numpy install problems
by Michael D. Risser 27 Jul '01

27 Jul '01

When attempting to install Numeric 17.0 with Python 1.5.2 and Distutils 1.0 on Red Hat 7.0, I get the following error after issuing the command 'python setup.py install' Traceback (innermost last): File "setup.py", line 15, in ? vs = map(string.atoi, v.groups()) AttributeError: 'None' object has no attribute 'groups' This error occurs regardless of whether or not I am root. I have also tried uninstalling the Red Hat Python packages and installing all from source, but I get the same error. Any help would be appreciated. Thanks.

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[Q]Best way for an array operation?
by Daehyok Shin 04 May '01

04 May '01

What is the best Numpy way for the following work? for i in range(len(x)): if x[i] > 0: y[i] = v[i] z[i] = u[i]+2 Daehyok Shin (Peter)

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Is this a wheel?
by Jon Saenz 08 Feb '01

08 Feb '01

Hello, there. I needed last Saturday a function which returns the greatest/smallest element of a NumPy array. I seeked through the documentation and found the argmax/argmin functions. However, they must be called recursively to find the greatest(smallest) element of a multidimendional array. As I needed to process a BIG dataset of multidimensional arrays, I wrote a function in C which returns as a NumPy array shaped (2,) the [smallest one,biggest one] elements in an arbitrarily shaped NumPy array. It is pure C and works for multidimensional arrays. The return typecode is the same of the input array (except with complex numbers, which compare numbers through their modules). I can make this function available to general public by means of my WEB page or my starship account as a module. However, I wonder: a) Is this a wheel already invented some 40,000 years ago? May be I missed something in the manual? b) If the answer to the previous question is NO, would you (main developers) be interested in making it available as one of the "general purpose" NumPy functions? It is quite general-purpose, indeed. I have needed it five times or so in the last two years... Looking after your comments. Jon Saenz. | Tfno: +34 946012470 Depto. Fisica Aplicada II | Fax: +34 944648500 Facultad de Ciencias. \\ Universidad del Pais Vasco \\ Apdo. 644 \\ 48080 - Bilbao \\ SPAIN

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[ANN] Numeric-17.3.0.tar.gz available
by Paul F. Dubois 30 Jan '01

30 Jan '01

Numeric Python 17.3.0 is available in source form at http://sourceforge.net/projects/numpy This is the last planned release in the 17 family. Binary versions will appear later -- developers, please help. Release 18 will require Python 2.1. Several of the new features in Python 2.1 are specifically meant to enable improvements in Numeric and we are going to try to take advantage of them. Paul F. Dubois Program for Climate Model Diagnosis and Intercomparison Lawrence Livermore National Laboratory

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Gnuplot.py version 1.5 released
by Michael Haggerty 27 Jan '01

27 Jan '01

This is to announce the release of version 1.5 of Gnuplot.py. Gnuplot.py is a Python [1] package that allows you to create graphs from within Python using the gnuplot [2] plotting program. Gnuplot.py can be obtained from http://gnuplot-py.sourceforge.net/ Prerequisites (see footnotes): the Python interpreter [1] the Python Numeric module [3] the gnuplot program [2] Some ways this package can be used: 1. Interactive data processing: Use Python's excellent Numeric package to create and manipulate arrays of numbers, and use Gnuplot.py to visualize the results. 2. Web graphics: write CGI scripts in Python that use gnuplot to output plots in GIF format and return them to the client. 3. Glue for numerical applications (this is my favorite): wrap your C++/C/Fortran subroutines so that they are callable from Python, then you can perform numerical computations interactively from scripts or from the command line and use Gnuplot.py to plot the output on the fly. 4. Compute a series of datasets in Python and plot them one after the other using Gnuplot.py to produce a crude animation. New features in this version: + Added distutils support. + Broke up the module a bit for better maintainability. The most commonly-used facilities are still available through "import Gnuplot", but some specialized things have been moved to separate modules, in particular funcutils.py and PlotItems.py. + funcutils.tabulate_function() can be used to evaluate a function on a 1-D or 2-D grid of points (this replaces grid_function, which only worked with 2-D grids). + Added two helper functions, funcutils.compute_Data and funcutils.compute_GridData, which compute a function's values on a set of points and package the results into a PlotItem. + GridFunc is no longer an independent class; it is now a factory function that returns a GridData. GridFunc is deprecated in favor of funcutils.compute_GridData. + Changed set_option to work from a table, so that it doesn't need to be overloaded so often. + Implemented test_persist for each platform to make it easier for users to determine whether the `-persist' option is supported. + Added a prefer_persist option to serve as the default `persist' choice. + Following a suggestion by Jannie Hofmeyr, use "from os import popen" for Python 2.0 under Windows. I don't use Windows, so let me know how this works. + Added support for the `axes' and `smooth' options of the `plot' command. + Reworked the comment strings in an effort to make them work nicely with happydoc. Features already present in older versions: + Two and three-dimensional plots. + Plot data from memory, from a file, or from an expression. + Support for multiple simultaneous gnuplot sessions. + Can pass arbitrary commands to the gnuplot program. + Object oriented, extensible design with several built-in types of plot items. + Portable and easy to install (nothing to compile except on Windows). + Support for MS Windows, using the `pgnuplot.exe' program. + Support for sending data to gnuplot as `inline' or `binary' data. These are optimizations that also remove the need for temporary files. Temporary files are still the default. Footnotes: ---------- [1] Python <http://www.python.org> is an excellent object-oriented scripting/rapid development language that is also especially good at gluing programs together. [2] gnuplot <http://www.gnuplot.org/> is a free, popular, very portable plotting program with a command-line interface. It can make 2-d and 3-d plots and can output to myriad printers and graphics terminals. [3] The Numeric Python extension <http://numpy.sourceforge.net/> is a Python module that adds fast and convenient array manipulations to the Python language. -- Michael Haggerty mhagger(a)alum.mit.edu

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numpy.org redirection
by John A. Turner 23 Jan '01

23 Jan '01

some time ago I registered the domain numpy.org with the intention of donating it to the group just thought about it again today, and realized I could easily redirect it, so my question is: o does anyone object to my doing that? o where should it point, here? http://numpy.sourceforge.net/ or here? http://sourceforge.net/projects/numpy if someone feels strongly that I should transfer ownership of the domain to someone more central to development, etc., I'll be happy to do that - otherwise I'm happy just redirecting and renewing it as it comes up, or at some point setting up real hosting of the domain somewhere (sourceforge?) -- John A. Turner, Ph.D. Senior Research Associate Blue Sky Studios, 44 S. Broadway, White Plains, NY 10601 http://www.blueskystudios.com/ (914) 259-6319

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RE: [Numpy-discussion] Questions about organization (fwd)
by Houman G 22 Jan '01

22 Jan '01

On Sun, Jan 21, 2001 at 12:36:37PM -0800, Greg Stein wrote: > FYI about what? I'm not sure that I see the point here. > > Are you trying to say that ActiveState can provide tools for packaging? > Maybe that we can get NumPy packaged for people? This one, I believe. HoumanG has been working on PyPM (like PPM for Python) for which he is creating appropriate setup.py scripts for packages such as NumPy. I wrote a new setup.py script for NumPy a week ago. The script I wrote builds the RANLIB and the LALITE as part of the core NumPy; and the binary distribution of NumPy built with my script also installs the RANLIB and LALITE. If the question is that Distutils supports a source tree structure like the one NumPy has, the question is no. However, I made a patch (for Distutils) and submitted to SourceForge which allows the source tree to be spread in more than one directory. A copy of the patch is in the attachment. Houman

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calling numpy from C++
by Edward_A._Damerau＠dadebehring.com 22 Jan '01

22 Jan '01

I've got Python 20 and numerical python installed and running, i.e., I can run python scripts and call import module Numerical and use arrays,etc. I've also been successful at calling python scripts from C/C++ code (MSVC++ 6.0) - Py_Initialize(), Py_BuildValue() etc. and building the de-bug version of python20.dll (python20_d.dll) so I can debug-step through the code. However, I can't seem to be able to call numpy functions from C/C++ - PyArray_FromDims(), etc. My code will compile and link but, at runtime, I get an exception error. It seems that either I need to create a numpy.dll that will live in winnt/system32 or somehow need to modify python20.dll to include the numpy functions. How do I do that? Thanks.

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Debug version of numpy for Win32
by Edward_A._Damerau＠dadebehring.com 22 Jan '01

22 Jan '01

Has anyone built a debug version of _numpy.pyd (_numpy_d.pyd) for Windows NT (MS Visual Studio C++ 6.0)?

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