Mailman 3 October 2014 - NumPy-Discussion

Copyright status of NumPy binaries on Windows/OS X
by Andrew Collette 11 Oct '14

11 Oct '14

Hi all, I am working with the HDF Group on a new open-source viewer program for HDF5 files, powered by NumPy, h5py, and wxPython. On Windows, since people don't typically have Python installed, we are looking to distribute the application using PyInstaller, which embeds dependencies like NumPy. Likewise for OS X (using Py2App). We would like to make sure we don't accidentally include non-open-source components... I recall there was some discussion here about using the Intel math libraries for binary releases on various platforms. Do the releases on SourceForge or PyPI use any proprietary code? We'd like to avoid building NumPy ourselves if we can avoid it. Apologies if this is explained somewhere, but I couldn't find it. Thanks! Andrew Collette

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fsin on Intel
by Alan G Isaac 11 Oct '14

11 Oct '14

This is not NumPy specific but may still interest list members: http://randomascii.wordpress.com/2014/10/09/intel-underestimates-error-boun… Alan Isaac

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use ufunc for arbitrary positional arguments?
by Benjamin Root 11 Oct '14

11 Oct '14

I have a need to "and" together an arbitrary number of boolean arrays. np.logical_and() expects only two positional arguments. There has got to be some sort of easy way to just and these together using the ufunc mechanism, right? Cheers! Ben Root

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Re: [Numpy-discussion] Extracting individual columns in Numpy (suchith)
by Juan 09 Oct '14

09 Oct '14

> Date: Thu, 09 Oct 2014 11:12:31 +0530 > From: suchith <suchithjn22(a)gmail.com> > Subject: [Numpy-discussion] Extracting individual columns in Numpy > To: numpy-discussion(a)scipy.org > Message-ID: <54362047.10102(a)gmail.com> > Content-Type: text/plain; charset="utf-8" > > How to extract individual columns from a numpy array? > For example, consider this script > > import numpy as np > a = np.array([[1,2,3],[4,5,6],[7,8,9]]) > a[0][:] > a[:][0] > > Now both a[:][0] and a[0][:] are outputting the same result, i.e > np.array([1,2,3]). If I want to extract the array [[1],[4],[7]] then > what should I do? Is it possible to add this feature? If so, which > file(s) should I edit? > > I know C,C++ and Python programming and I am new to open-source software > development. Please help me. > Try: In [2]: import numpy as np In [3]: a = np.array([[1,2,3],[4,5,6],[7,8,9]]) In [4]: a[0][:] Out[4]: array([1, 2, 3]) In [5]: a[:][0] Out[5]: array([1, 2, 3]) In [6]: a[0,:] Out[6]: array([1, 2, 3]) In [7]: a[:,0] Out[7]: array([1, 4, 7]) Syntax is different for numpy arrays. Regards, Juan

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Extracting individual columns in Numpy
by suchith 09 Oct '14

09 Oct '14

How to extract individual columns from a numpy array? For example, consider this script import numpy as np a = np.array([[1,2,3],[4,5,6],[7,8,9]]) a[0][:] a[:][0] Now both a[:][0] and a[0][:] are outputting the same result, i.e np.array([1,2,3]). If I want to extract the array [[1],[4],[7]] then what should I do? Is it possible to add this feature? If so, which file(s) should I edit? I know C,C++ and Python programming and I am new to open-source software development. Please help me. I have attached the screenshot with this mail. Thanks Suchith.J.N

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Re: [Numpy-discussion] Extracting individual columns in Numpy
by Andrew Nelson 09 Oct '14

09 Oct '14

>import numpy as np a = np.array([[1,2,3],[4,5,6],[7,8,9]]) a[0][:] a[:][0] Now both a[:][0] and a[0][:] are outputting the same result, i.e np.array([1,2,3]). If I want to extract the array [[1],[4],[7]] then what should I do? Is it possible to add this feature? The feature is already there: a[:, 0] -- _____________________________________ Dr. Andrew Nelson _____________________________________

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ANN: Pandas 0.15.0 Release Candiate 1
by Jeff Reback 07 Oct '14

07 Oct '14

Hi, I'm pleased to announce the availability of the first release candidate of Pandas 0.15.0. Please try this RC and report any issues here: Pandas Issues <https://github.com/pydata/pandas/issues> We will be releasing officially in 1-2 weeks or so. This is a major release from 0.14.1 and includes a number of API changes, several new features, enhancements, and performance improvements along with a large number of bug fixes. Highlights include: - Drop support for numpy < 1.7.0 - The Categorical type was integrated as a first-class pandas type - New scalar type Timedelta, and a new index type TimedeltaIndex - New DataFrame default display for df.info() to include memory usage - New datetimelike properties accessor .dt for Series - Split indexing documentation into Indexing and Selecting Data and MultiIndex / Advanced Indexing - Split out string methods documentation into Working with Text Data - read_csv will now by default ignore blank lines when parsing - API change in using Indexes in set operations - Internal refactoring of the Index class to no longer sub-class ndarray - dropping support for PyTables less than version 3.0.0, and numexpr less than version 2.1 Here are the full whatsnew and documentation links: v0.15.0 Whatsnew <http://pandas.pydata.org/pandas-docs/version/0.15.0/whatsnew.html> v0.15.0 Documentation Page <http://pandas.pydata.org/pandas-docs/version/0.15.0/> Source tarballs, and windows builds are available here: Pandas v0.15.0rc1 Release <https://github.com/pydata/pandas/releases> A big thank you to everyone who contributed to this release! Jeff

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f2py and debug mode
by Bayard 06 Oct '14

06 Oct '14

Hello to all. I'm aiming to wrap a Fortran program into Python. I started to work with f2py, and am trying to setup a debug mode where I could reach breakpoints in Fortran module launched by Python. I've been looking in the existing post, but not seeing things like that. I'm used to work with visual studio 2012 and Intel Fortran compiler, I have tried to get that point doing : 1) Run f2py -m to get *.c wrapper 2) Embed it in a C Project in Visual Studio, containing also with fortranobject.c and fortranobject.h, 3) Create a solution which also contains my fortran files compiled as a lib 4) Generate in debug mode a "dll" with extension pyd (to get to that point name of the "main" function in Fortran by "_main"). I compiled without any error, and reach break point in C Wrapper, but not in Fortran, and the fortran code seems not to be executed (whereas it is when compiling with f2py -c). Trying to understand f2py code, I noticed that f2py is not only writing c-wrapper, but compiling it in a specific way. Is there a way to get a debug mode in Visual Studio with f2py (some members of the team are used to it) ? Any alternative tool we should use for debugging ? Thanks for answering Ferdinand --- Ce courrier électronique ne contient aucun virus ou logiciel malveillant parce que la protection avast! Antivirus est active. http://www.avast.com

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Round away from zero (towards +/- infinity)
by T J 05 Oct '14

05 Oct '14

Is there a ufunc for rounding away from zero? Or do I need to do x2 = sign(x) * ceil(abs(x)) whenever I want to round away from zero? Maybe the following is better? x_ceil = ceil(x) x_floor = floor(x) x2 = where(x >= 0, x_ceil, x_floor) Python's round function goes away from zero, so I am looking for the NumPy equivalent (and using vectorize() seems undesirable). In this sense, it seems that having a ufunc for this type of rounding could be helpful. Aside: Is there interest in a more general around() that allows users to specify alternative tie-breaking rules, with the default staying 'round half to nearest even'? [1] Also, what is the difference between NumPy's fix() and trunc() functions? It seems like they achieve the same goal. trunc() was added in 1.3.0. So is fix() just legacy? --- [1] http://stackoverflow.com/questions/16000574/tie-breaking-of-round-with-numpy

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0/0 == 0?
by T J 04 Oct '14

04 Oct '14

Hi, I'm using NumPy 1.8.2: In [1]: np.array(0) / np.array(0) Out[1]: 0 In [2]: np.array(0) / np.array(0.0) Out[2]: nan In [3]: np.array(0.0) / np.array(0) Out[3]: nan In [4]: np.array(0.0) / np.array(0.0) Out[4]: nan In [5]: 0/0 --------------------------------------------------------------------------- ZeroDivisionError Traceback (most recent call last) <ipython-input-6-6549dea6d1ae> in <module>() ----> 1 0/0 ZeroDivisionError: integer division or modulo by zero Out[1] seems odd. I get the right value in 1.8.1. Was this fixed for 1.9.0?

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