Mailman 3 June 2008 - NumPy-Discussion

Re: [Numpy-discussion] [numpy-discussion] inconsistent behavior in binary_repr
by Damian Eads June 4, 2008

June 4, 2008

Whoops. In one xterm, I'm going off the Fedora package and in the other, the SVN source tree. SVN seems to work. Sorry for the unnecessary message. On Wed, Jun 4, 2008 at 2:59 AM, Robert Kern wrote: > In [27]: numpy.binary_repr(0, width=8) > Out[27]: '0' > > Is this what the output is intended to be for the 0 case? No. SVN trunk seems to work correctly. What version of numpy do you have?

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Which Python to Use on OSX, Was: 1.1.0 OSX Installer Fails Under 10.5.3?
by J. Stark June 4, 2008

June 4, 2008

Robert, I see your point, but why not just install a separate NumPy to run with the system Python? That is what I have always done in the past without problems. I guess I always feel a sense of uncertainty with having two separate Python installations as to which actually gets used in any particular situation. I appreciate that for experts who use Python daily, this isn't an issue, but for someone like myself who may have gaps of several months between projects that use Python, this is a real issue as I forget those kinds of subtleties. J. >On Wed, Jun 4, 2008 at 1:48 AM, J. Stark <j.stark(a)imperial.ac.uk> wrote: >> On this topic, I would be interested to hear people's advice on using >> the system provided Python v an independent install. In 25 years of >> using Macs I have learned through several painful lessons that its >> wise to customize the system as little as possible: this minimizes >> both conflicts and reduces problems when doing system upgrades. I >> have therefore always used the default Python provided by OSX, so far >> with no obvious disadvantages for the types of scripts I use >> (primarily home written SciPy scientific code). However, I note that >> many people run either the pythomac.org distribution, or the >> ActiveState. What are the advantages to this? > >By installing a separate Python, you are actually customizing the >system *less* than if you used the system Python and installed a bunch >of extra packages. Parts of Apple's software uses the system Python. >If you upgrade packages inside there (like numpy!) you might run into >problems. > >-- >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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inconsistent behavior in binary_repr
by Damian Eads June 4, 2008

June 4, 2008

Hi, I noticed some odd behavior in binary_repr when the width parameter is used. In most cases it works, In [23]: numpy.binary_repr(1, width=8) Out[23]: '00000001' In [24]: numpy.binary_repr(2, width=8) Out[24]: '00000010' In [25]: numpy.binary_repr(3, width=8) Out[25]: '00000011' In [26]: numpy.binary_repr(4, width=8) Out[26]: '00000100' except when 0 is passed, I get the following In [27]: numpy.binary_repr(0, width=8) Out[27]: '0' Is this what the output is intended to be for the 0 case? Damian

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Re: [Numpy-discussion] 1.1.0 OSX Installer Fails Under 10.5.3?
by Robert Kern June 4, 2008

June 4, 2008

On Wed, Jun 4, 2008 at 1:48 AM, J. Stark <j.stark(a)imperial.ac.uk> wrote: > On this topic, I would be interested to hear people's advice on using > the system provided Python v an independent install. In 25 years of > using Macs I have learned through several painful lessons that its > wise to customize the system as little as possible: this minimizes > both conflicts and reduces problems when doing system upgrades. I > have therefore always used the default Python provided by OSX, so far > with no obvious disadvantages for the types of scripts I use > (primarily home written SciPy scientific code). However, I note that > many people run either the pythomac.org distribution, or the > ActiveState. What are the advantages to this? By installing a separate Python, you are actually customizing the system *less* than if you used the system Python and installed a bunch of extra packages. Parts of Apple's software uses the system Python. If you upgrade packages inside there (like numpy!) you might run into problems. -- 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: [Numpy-discussion] 1.1.0 OSX Installer Fails Under 10.5.3?
by J. Stark June 4, 2008

June 4, 2008

Chris, many thanks. Could I suggest that this information be featured prominently in the Read Me in the Installer, and perhaps also at http://www.scipy.org/Download where this is given as the official binary distribution for MacOSX. You might want to change the error message too, since I think that some people will interpret "System Python" to mean the default Python provided by the standard system install. Since this is 2.5.1 on Leopard, the error message could be confusing. On this topic, I would be interested to hear people's advice on using the system provided Python v an independent install. In 25 years of using Macs I have learned through several painful lessons that its wise to customize the system as little as possible: this minimizes both conflicts and reduces problems when doing system upgrades. I have therefore always used the default Python provided by OSX, so far with no obvious disadvantages for the types of scripts I use (primarily home written SciPy scientific code). However, I note that many people run either the pythomac.org distribution, or the ActiveState. What are the advantages to this? Many thanks J. >Jaroslav, > >The installer works with the MacPython from python.org, not Apple's python >(the one that ships with Leopard). > >The MacPython is installed in the /Library/Frameworks... It should work if >your python is here: > >cburns$ python -c "import sys; print sys.prefix" >/Library/Frameworks/Python.framework/Versions/2.5 > >Won't work if your python is here: > >cburns$ python-apple -c "import sys; print sys.prefix" >/System/Library/Frameworks/Python.framework/Versions/2.5 > >Sorry for the confusion, >Chris > >On Tue, Jun 3, 2008 at 2:33 PM, J. Stark <j.stark(a)imperial.ac.uk> wrote: > >> I have just tried to run the 1.1.0 OSX installer on a MacBookAir >> running 10.5.3 and the installer fails with >> >> "You cannot install numpy 1.1.0 on this volume. numpy requires System >> Python 2.5 to install." >> >> The system python version reports as >> >> jaroslav$ python >> Python 2.5.1 (r251:54863, Apr 15 2008, 22:57:26) >> [GCC 4.0.1 (Apple Inc. build 5465)] on darwin >> >> which is the same version that Leopard has had all along, as far as I >> am aware. On the the other hand, there have been some reports on >> PythonMac about odd python behaviour following the 10.5.3 upgrade. >> >> Has anybody used this installer successfully under 10.5.3, and/or >> have any idea of what is going on. >> >> Incidentally, this is a new machine with just the default system >> installation. >> >> Jaroslav

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get range of numpy type
by Christopher Burns June 4, 2008

June 4, 2008

Is there a way to get the range of a numpy type? I'd like to clamp a parameter to be within the range of a numpy type, np.uint8, np.uint32... Something like: if x > max_value_of(np.uint8): x = max_value_of(np.uint8) -- Christopher Burns Computational Infrastructure for Research Labs 10 Giannini Hall, UC Berkeley phone: 510.643.4014 http://cirl.berkeley.edu/

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How does Boolean indexing work?
by Anne Archibald June 4, 2008

June 4, 2008

Hi, I thought it might be useful to summarize the different ways to use numpy's indexing, slice and fancy. The document so far is here: http://www.scipy.org/Cookbook/Indexing While writing it I ran into some puzzling issues. The first of them is, how is Boolean indexing supposed to work when given more than one array? What I mean is, suppose we have the following array: In [3]: A = np.arange(9) In [4]: B = np.reshape(A,(3,3)) In [5]: B Out[5]: array([[0, 1, 2], [3, 4, 5], [6, 7, 8]]) Then we can use boolean indexing to select some rows or some columns: In [12]: B[np.array([True,False,True]),:] Out[12]: array([[0, 1, 2], [6, 7, 8]]) In [13]: B[:,np.array([True,False,True])] Out[13]: array([[0, 2], [3, 5], [6, 8]]) But if you supply Boolean arrays in both row and column places, rather than select the corresponding rows and columns, you get something basically mysterious: In [14]: B[np.array([True,False,True]),np.array([True,True,False])] Out[14]: array([0, 7]) In [15]: B[np.array([True,False,True]),np.array([True,False,False])] Out[15]: array([0, 6]) In [16]: B[np.array([True,False,True]),np.array([True,True,True])] --------------------------------------------------------------------------- <type 'exceptions.ValueError'> Traceback (most recent call last) /home/peridot/<ipython console> in <module>() <type 'exceptions.ValueError'>: shape mismatch: objects cannot be broadcast to a single shape What is going on here? Thanks, Anne

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Re: [Numpy-discussion] 1.1.0 OSX Installer Fails Under 10.5.3?
by Christopher Burns June 4, 2008

June 4, 2008

Jaroslav, The installer works with the MacPython from python.org, not Apple's python (the one that ships with Leopard). The MacPython is installed in the /Library/Frameworks... It should work if your python is here: cburns$ python -c "import sys; print sys.prefix" /Library/Frameworks/Python.framework/Versions/2.5 Won't work if your python is here: cburns$ python-apple -c "import sys; print sys.prefix" /System/Library/Frameworks/Python.framework/Versions/2.5 Sorry for the confusion, Chris On Tue, Jun 3, 2008 at 2:33 PM, J. Stark <j.stark(a)imperial.ac.uk> wrote: > I have just tried to run the 1.1.0 OSX installer on a MacBookAir > running 10.5.3 and the installer fails with > > "You cannot install numpy 1.1.0 on this volume. numpy requires System > Python 2.5 to install." > > The system python version reports as > > jaroslav$ python > Python 2.5.1 (r251:54863, Apr 15 2008, 22:57:26) > [GCC 4.0.1 (Apple Inc. build 5465)] on darwin > > which is the same version that Leopard has had all along, as far as I > am aware. On the the other hand, there have been some reports on > PythonMac about odd python behaviour following the 10.5.3 upgrade. > > Has anybody used this installer successfully under 10.5.3, and/or > have any idea of what is going on. > > Incidentally, this is a new machine with just the default system > installation. > > Jaroslav > _______________________________________________ > Numpy-discussion mailing list > Numpy-discussion(a)scipy.org > http://projects.scipy.org/mailman/listinfo/numpy-discussion > -- Christopher Burns Computational Infrastructure for Research Labs 10 Giannini Hall, UC Berkeley phone: 510.643.4014 http://cirl.berkeley.edu/

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linked variables?
by Payton Gardner June 4, 2008

June 4, 2008

Its probably something simple I don't understand but... I've written a dummy function which takes an array m. I'd like it to return a changed array m_i, and not change the initial array m. I call it with mm = dummy(m); 3 from numpy import *; 4 def dummy(m): 5 m_o = m; 6 pdb.set_trace(); 7 m_step = 100; 8 m_i = m_o; 9 dummy = m; 10 dummy2 = m_o; 11 dummy3 = m_o; 12 i = 0; 13 m_i[i] = m_i[i] + m_step; 14 return(m_i); But after line 13 m, m_o, dummy, dummy2, and dummy3 are all changed by m_step, as well mm which is in a different name space. All I've asked it to do is change m_i. What's happening? Thanks, Payton Payton Gardner University of Utah Department of Geology and Geophysics

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1.1.0 OSX Installer Fails Under 10.5.3?
by J. Stark June 3, 2008

June 3, 2008

I have just tried to run the 1.1.0 OSX installer on a MacBookAir running 10.5.3 and the installer fails with "You cannot install numpy 1.1.0 on this volume. numpy requires System Python 2.5 to install." The system python version reports as jaroslav$ python Python 2.5.1 (r251:54863, Apr 15 2008, 22:57:26) [GCC 4.0.1 (Apple Inc. build 5465)] on darwin which is the same version that Leopard has had all along, as far as I am aware. On the the other hand, there have been some reports on PythonMac about odd python behaviour following the 10.5.3 upgrade. Has anybody used this installer successfully under 10.5.3, and/or have any idea of what is going on. Incidentally, this is a new machine with just the default system installation. Jaroslav

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