[Numpy-discussion] Compiling NumPy for iOS PyQt app?
I have a PyQt app running on iOS and would like to add NumPy to improve calculation speed. I see a few python interpreters in the app store which use NumPy so it must be possible, however I have not been able to find any information on the build process for the iOS cross compile. We are building a python with all libraries static linked. Here is the environment: iOS 8.0+ Python 3.4 PyQt 5.5 Qt 5.5 pyqtdeploy Any help getting NumPy compiled into the iOS app? Thank you, David ___ NumPy-Discussion mailing list NumPy-Discussion@scipy.org https://mail.scipy.org/mailman/listinfo/numpy-discussion
Re: [Numpy-discussion] Question about structure arrays
On Nov 7, 2015 2:58 PM, "aerojockey" wrote: > > Hello, > > Recently I made some changes to a program I'm working on, and found that the > changes made it four times slower than before. After some digging, I found > out that one of the new costs was that I added structure arrays. Inside a > low-level loop, I create a structure array, populate it Python, then turn it > over to some handwritten C code for processing. It turned out that, when > passed a structure array as a dtype, numpy has to parse the dtype, which > included calls to re.match and eval. > > Now, this is not a big deal for me to work around by using ordinary slicing > and such, and also I can improve things by reusing arrays. Since this is > inner loop stuff, sacrificing readability for speed is an appropriate > tradeoff. > > Nevertheless, I was curious if there was a way (or any plans for there to be > a way) to compile a struture array dtype. I realize it's not the > bread-and-butter of numpy, but it turned out to be a very convenient feature > for my use case (populating an array of structures to pass off to C). I was just looking into structured arrays. In case it is relevant: Are you using certain 1.10? They are apparently a LOT slower than 1.9.3, an issue which will be fixed in a future version. David ___ NumPy-Discussion mailing list NumPy-Discussion@scipy.org https://mail.scipy.org/mailman/listinfo/numpy-discussion
[Numpy-discussion] Unable to pickle numpy array on iOS
I have an application running on iOS where I pickle a numpy array in order to save it for later use. However, I receive the following error: pickle.dumps(arr) ... _pickle.PicklingError: Can't pickle : import of module 'multiarray' failed On a desktop system (OSX), there is no problem dumping the array. I am using NumPy v1.9.3 Any ideas on why this might be happening? Thank you, David ___ NumPy-Discussion mailing list NumPy-Discussion@scipy.org https://mail.scipy.org/mailman/listinfo/numpy-discussion
Re: [Numpy-discussion] State-of-the-art to use a C/C++ library from Python
On Wed, Aug 31, 2016 at 2:28 PM, Michael Bieri wrote: > Hi all > > There are several ways on how to use C/C++ code from Python with NumPy, as > given in http://docs.scipy.org/doc/numpy/user/c-info.html . Furthermore, > there's at least pybind11. > > I'm not quite sure which approach is state-of-the-art as of 2016. How > would you do it if you had to make a C/C++ library available in Python > right now? > > In my case, I have a C library with some scientific functions on matrices > and vectors. You will typically call a few functions to configure the > computation, then hand over some pointers to existing buffers containing > vector data, then start the computation, and finally read back the data. > The library also can use MPI to parallelize. > I have been delighted with Cython for this purpose. Great integration with NumPy (you can access numpy arrays directly as C arrays), very python like syntax and amazing performance. Good luck, David ___ NumPy-Discussion mailing list NumPy-Discussion@scipy.org https://mail.scipy.org/mailman/listinfo/numpy-discussion
