Mailman 3 May 2003 - NumPy-Discussion

Numarray-0.5 released
by Todd Miller May 7, 2003

May 7, 2003

Release Notes for numarray-0.5 Numarray is an array processing package designed to efficiently manipulate large multi-dimensional arrays. Numarray is modelled after Numeric and features c-code generated from python template scripts, the capacity to operate directly on arrays in files, and improved type promotions. I. ENHANCEMENTS 1. Universal Function Overhead Reduction The constant time overhead for most universal functions has been reduced by a factor of 10-20. This results in better performance for small arrays. 2. FFT mode and IRAF boundary modes added to Convolve.convolve2d There's now an FFT switch for the 2d convolution function in the Convolve package; when set to 1, convolution is performed via the FFT rather than using the naiive algorithm. In addition, convolve2d now supports boundary modes which are identical to IRAF's convolution function. 3. Numarray is now supported by f2py Numarray numerical arrays can now be used with f2py wrappers for Fortran code. To compile f2py wrapped extensions for numarray, use the switch -DNUMARRAY on the f2py command line. Support is currently limited to f77 and numerical arrays. II. BUGS FIXED 650926 exotic type coercions 653424 Convolve.boxcar boundary bug 653429 python setup.py build 654669 array index by list 655942 logical operator reductions 657058 inverse real fft bug 677796 byteswap not working 709956 error summing over large boolean arrays 710480 MLab.median makes unnecessary msort call 714537 conjugate function changes its argument See http://sourceforge.net/tracker/?atid=450446&group_id=1369&func=browse for more details. III. CAUTIONS 1. Due to some module renamings, numarray-0.5 will not install correctly on top of an existing numarray installation. Before installing numarray-0.5 remove your old version of numarray. 2. Due to reorganization of the C-API, numarray extensions must be recompiled. 3. For numarray-0.5 and up, the byteswap related methods have been redefined: a.byteswap() swaps but leaves byteorder alone a.togglebyteorder() Does "big" <-> "little" a._byteswap() now an alias for byteswap a._togglebyteorder() deleted 4. round() has been deprecated. Use around() instead. 5. Installing from source, the first time you run setup.py, you must specify --gencode, e.g.: python setup.py install --gencode WHERE ----------- Numarray-0.5 windows executable installers, source code, and manual is here: http://sourceforge.net/project/showfiles.php?group_id=1369 Numarray is hosted by Source Forge in the same project which hosts Numeric: http://sourceforge.net/projects/numpy/ The web page for Numarray information is at: http://stsdas.stsci.edu/numarray/index.html Trackers for Numarray Bugs, Feature Requests, Support, and Patches are at the Source Forge project for NumPy at: http://sourceforge.net/tracker/?group_id=1369 REQUIREMENTS ------------------------------ numarray-0.5 requires Python 2.2.2 or greater. AUTHORS, LICENSE ------------------------------ Numarray was written by Perry Greenfield, Rick White, Todd Miller, JC Hsu, Paul Barrett, Phil Hodge at the Space Telescope Science Institute. Thanks go to Jochen Kupper of the University of North Carolina for his work on Numarray and for porting the Numarray manual to TeX format. Thanks also to Edward C. Jones, Francesc Alted, Paul Dubois, Eric Jones, Travis Oliphant, Pearu Peterson and everyone who has contributed with comments and feedback. Numarray is made available under a BSD-style License. See LICENSE.txt in the source distribution for details. -- Todd Miller jmiller(a)stsci.edu STSCI / ESS / SSB

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numarray 0.5 bug
by Peter Verveer May 6, 2003

May 6, 2003

In numarray 0.5, the PyArray_ContiguousFromObject() does not appear to work correctly with Python scalar objects, if the requested type is not equal to the type of the object. (I believe that this function should convert the input to an array of the requested type?) For instance, PyArray_ContiguousFromObject(object, tInt32, 0, 1))) works correctly if object is a python integer, but not if it is a float number. Cheers, Peter -- Dr. Peter J. Verveer Cell Biology and Cell Biophysics Programme EMBL Meyerhofstrasse 1 D-69117 Heidelberg Germany Tel. : +49 6221 387245 Fax : +49 6221 387242 Email: Peter.Verveer(a)embl-heidelberg.de

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Question about numarray Bool type
by Peter Verveer May 6, 2003

May 6, 2003

Hi, In the numarray source code Bool is defined as a typedef to char. Does the Bool array type correspond to the Int8, or the UInt8 type? If I recall correctly, the char type may be signed or unsigned. Can I make any assumptions about the C type used to implement Bool at all? I guess at the Python level it does not matter what actual C type is used to implement bool arrays as it only represents boolean values. However, at the level of C extensions I would like to deal with Bool arrays by calling existing functions written for the appropiate C type. That would be somewhat simpler if Bool is always garantueed to be either a unsigned or a signed char type. Cheers, Peter. -- Dr. Peter J. Verveer Cell Biology and Cell Biophysics Programme EMBL Meyerhofstrasse 1 D-69117 Heidelberg Germany Tel. : +49 6221 387245 Fax : +49 6221 387242 Email: Peter.Verveer(a)embl-heidelberg.de

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Python global interpreter lock ...
by Andrew P. Lentvorski, Jr. May 5, 2003

May 5, 2003

I have been digging into Python threading and was curious as to whether I'm going to run into problems using Python threads with numpy. So, my questions are: 1) Does numpy (or numarray) release the Python GIL? 2) If not, why not? Is this simply something I could fix by making the changes myself, or are there larger reasons for not releasing the GIL? Thanks, -a

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numpy problem
by mtsbra003＠mail.uct.ac.za May 2, 2003

May 2, 2003

Hello I have installed python,numpy(latest),and numtut. So when testing the package could see the image that was supposed to come out. Per instruction I had to do the following: 1. from NumTut import* , 2. view(greece). But view brought nothing. Thanking you in advance Thats Bramley ------------------------------------------------- This mail sent through IMP: http://horde.org/imp/

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by james＠hello.com May 1, 2003

May 1, 2003

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