Mailman 3 April 2013 - NumPy-Discussion

Re: [Numpy-discussion] Raveling, reshape order keyword unnecessarily confuses index and memory ordering
by matti picus April 16, 2013

April 16, 2013

as a lurker, may I say that this discussion seems to have become non-productive? It seems all agree that docs needs improvement, perhaps a first step would be to suggest doc improvements, and then the need for renaming may become self-evident, or not. aww darn, ruined my lurker status. Matti Picus

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Pruned / sparse FFT 2D
by Daπid April 15, 2013

April 15, 2013

Hi, I have a sparse cloud of points of ~10^4 points randomly scattered around a triangular domain [1] from which I want to take the Fourier transform. I have been looking for algorithms and found one library, but only appears to be for the 1-D case (and seems there is no documentation). In [3] there is C code for the FFTW, but seems it code is itself pruned (pun intended). Does anyone have a clue about how to perform it? Speed is not a big issue, but accuracy is quite important. Thanks, David. [1] http://www.asaaf.org/~davidmh/coverage.png [2] https://pypi.python.org/pypi/pynfftls/1.0 [3] http://www.fftw.org/pruned.html

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ANN: numexpr 2.1 RC1
by Francesc Alted April 14, 2013

April 14, 2013

============================ Announcing Numexpr 2.1RC1 ============================ Numexpr is a fast numerical expression evaluator for NumPy. With it, expressions that operate on arrays (like "3*a+4*b") are accelerated and use less memory than doing the same calculation in Python. It wears multi-threaded capabilities, as well as support for Intel's VML library, which allows for squeezing the last drop of performance out of your multi-core processors. What's new ========== This version adds compatibility for Python 3. A bunch of thanks to Antonio Valentino for his excellent work on this.I apologize for taking so long in releasing his contributions. In case you want to know more in detail what has changed in this version, see: http://code.google.com/p/numexpr/wiki/ReleaseNotes or have a look at RELEASE_NOTES.txt in the tarball. Where I can find Numexpr? ========================= The project is hosted at Google code in: http://code.google.com/p/numexpr/ This is a release candidate 1, so it will not be available on the PyPi repository. I'll post it there when the final version will be released. Share your experience ===================== Let us know of any bugs, suggestions, gripes, kudos, etc. you may have. Enjoy! -- Francesc Alted

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Please stop bottom posting!!
by Chris Barker - NOAA Federal April 12, 2013

April 12, 2013

OK, OK, I know the fashion is to blast people with "please don't top post" messages -- it seems to have invaded all the mailing lists I'm on. But I don't get it. Most of us have threaded mail readers these days, so is it so hard to follow a thread? Maybe I'm a weirdo, but it is FAR more common for me to have been following a thread, and want to know what the latest comment is, then drop into the end of a long thread, and want to see the entire discussion in the most recent post. So why make me scroll WAY THE HECK down literally hundreds of lines to find your one: "+1" give me a break! Even if you have something significant and pithy to say, I still don't want to scroll through all that junk, and layers of 10+ >>>>>>>>>>> to find out the new stuff. (take a look at a the "Raveling, reshape order ..." thread to see what I mean. So, while I agree blind top posting is less than Ideal, I actually like it a bit better than blind bottom posting. Best of all is intelligent editing of the thread so far -- edit it down to the key points you are commenting on, and intersperse your comments. That way your email stands on its own as meaningful, but there is not a big pile of left over crap to wade through to read your fabulous pithy opinions.... OK, I've had my rant, carry on! -Chris -- Christopher Barker, Ph.D. Oceanographer Emergency Response Division NOAA/NOS/OR&R (206) 526-6959 voice 7600 Sand Point Way NE (206) 526-6329 fax Seattle, WA 98115 (206) 526-6317 main reception Chris.Barker(a)noaa.gov

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Non-Integer deprecations
by Sebastian Berg April 12, 2013

April 12, 2013

Hey all, just revisiting non-integer (index) deprecations (basically https://github.com/numpy/numpy/pull/2891). I believe for all natural integer arguments, it is correct to do a deprecation if the input is not an integer. (Technically most of these go through PyArray_PyIntAsIntp, and if not probably should) This affects all axes, shapes, strides, indices (as well as slices) and (in the future) possibly other integer arguments. Indexing already has a deprecation warning in master, but I think it should be moved further down into PyArray_PyIntAsIntp. Just a couple of minor things to note or I am wondering about: 1. Does anyone see a problem with rejecting python bools as not integers? Python does not do it, but for array indices they misbehave and I don't see a real reason to allow them even for other integer arguments. 2. This will mean that 1e4, etc. is not valid, 10**4 must be used. 3. Deprecate (maybe faster then the rest) that array.__index__() works for non 0-d arrays seems right, but makes me a bit wonder about __int__ and __float__. (This is unrelated though) 4. This will affect third party behavior using the public numpy conversion functions. These are long deprecations (but possibly the __index__ which I think already has a bug report as being wrong...) so if any problems occur there should be time to clear them. This is just a note in case someone sees any problems with the general plan. Regards, Sebastian

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Impossible to draw a direction of arrows in Python???
by Happyman April 12, 2013

April 12, 2013

Hi, I have encountered some problem while I was drawing a direction of arrow. I have point (x,y) coordinates and angle of them. What I want to do is that to draw arrow according to the given angle (just to show the point direction as an arrow in each point coordinate). Here, we should assume coordinates of '+x', '+y', '-x ', '-y' are 90, 0, 270, 180 degrees, respectively. I am a bit unfamiliar with Python drawing tools. I am still not sure to draw directional point (arrow based on angle) whether I use pylab or some other modules or.. still not sure at all. I put the following codes as a sample to give better description: import numpy as np import scipy as sp import pylab as pl def draw_line(x,y,angle): # Inputs: x = np.array([ 2, 4, 8, 10, 12, 14, 16]) y = np.array([ 5, 10, 15, 20, 25, 30, 35]) angles = np.array([45,275,190,100,280,18,45]) # First, draw (x,y) coordinate ??? # Second, according to the angle indicate the direction as an arrow ??? Thanks in advance for your friendly support, -- happy Man

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The "I" dtype character
by Georg Brandl April 12, 2013

April 12, 2013

Hi, is it intentional that "I" is supported as a dtype character, but cannot be suffixed with a size? >>> dtype('i1') dtype('int8') >>> dtype('I1') dtype('uint32') I know "u" is documented as unsigned integer, but this seems an unnecessary restriction that is confusing. thanks, Georg

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Scheduling the 1.7.1 and 1.8 releases
by Charles R Harris April 11, 2013

April 11, 2013

Hi All, There are now some 14 non-merge commits in the 1.7.x branch including the critical diagonal leak fix. I think there is maybe one more critical backport and perhaps several low priority fixes, documentation and such, but I think we should start up the release process with a goal of getting 1.7.1 out by the middle of April. The development branch has been accumulating stuff since last summer, I suggest we look to get it out in May, branching at the end of this month. Thoughts? Chuck

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OpenOpt Suite release 0.45
by Dmitrey April 10, 2013

April 10, 2013

Hi all, > I'm glad to inform you about new OpenOpt Suite release 0.45 (2013-March-15): * Essential improvements for FuncDesigner interval analysis (thus affect interalg) * Temporary walkaround for a serious bug in FuncDesigner automatic differentiation kernel due to a bug in some versions of Python or NumPy, may affect optimization problems, including (MI)LP, (MI)NLP, TSP etc * Some other minor bugfixes and improvements > > --------------------------- > Regards, D. > http://openopt.org/Dmitrey

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Import error while freezing with cxfreeze
by Anand Gadiyar April 10, 2013

April 10, 2013

Hi all, I have a small program that uses numpy and scipy. I ran into a couple of errors while trying to use cxfreeze to create a windows executable. I'm running Windows 7 x64, Python 2.7.3 64-bit, Numpy 1.7.1rc1 64-bit, Scipy-0.11.0 64-bit, all binary installs from < http://www.lfd.uci.edu/~gohlke/pythonlibs/> I was able to replicate this with scipy-0.12.0c1 as well. 1) "from scipy import constants" triggers the below: Traceback (most recent call last): File "D:\Python27\lib\site-packages\cx_Freeze\initscripts\Console.py", line 27, in <module> exec_code in m.__dict__ File "mSimpleGui.py", line 10, in <module> File "mSystem.py", line 7, in <module> File "D:\Python27\lib\site-packages\scipy\__init__.py", line 64, in <module> from numpy import show_config as show_numpy_config File "D:\Python27\lib\site-packages\numpy\__init__.py", line 165, in <module> from core import * AttributeError: 'module' object has no attribute 'sys' 2) "from scipy import interpolate" triggers the below: Traceback (most recent call last): File "D:\Python27\lib\site-packages\cx_Freeze\initscripts\Console.py", line 27, in <module> exec_code in m.__dict__ File "mSimpleGui.py", line 10, in <module> File "mSystem.py", line 9, in <module> File "mSensor.py", line 10, in <module> File "D:\Python27\lib\site-packages\scipy\interpolate\__init__.py", line 154, in <module> from rbf import Rbf File "D:\Python27\lib\site-packages\scipy\interpolate\rbf.py", line 50, in <module> from scipy import linalg ImportError: cannot import name linalg I've attached a couple of small patches that fix these errors for me, but I'm not sure if these are the best way to fix. Could you please take a look? I'd be happy to test alternative fixes. Thanks in advance, Anand

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