Mailman 3 September 2008 - NumPy-Discussion

PyArray_SETITEM macro ends in semicolon
by jason-sage＠creativetrax.com 26 Sep '08

26 Sep '08

I'm working on getting the Sage matrices for real/complex doubles to use numpy as a backend. In this, I'm using the PyArray_SETITEM macro from within Cython. However, Cython wraps the macro in a function call to convert the output to a Python value: __pyx_1 = PyInt_FromLong(PyArray_SETITEM(__pyx_v_self->_matrix_numpy, PyArray_GETPTR2(__pyx_v_self->_matrix_numpy, __pyx_v_i, __pyx_v_j), __pyx_v_value)); However, after preprocessing, because of the semicolon at the end of the SETITEM macro, we get: PyInt_FromLong(((PyArrayObject *)(__pyx_v_self->_matrix_numpy))->descr->f->setitem((PyObject *)(__pyx_v_value), (char *)(((void *)((((PyArrayObject *)(__pyx_v_self->_matrix_numpy))->data) + (__pyx_v_i)*(((PyArrayObject *)(__pyx_v_self->_matrix_numpy))->strides)[0] + (__pyx_v_j)*(((PyArrayObject *)(__pyx_v_self->_matrix_numpy))->strides)[1]))), (PyArrayObject *)(__pyx_v_self->_matrix_numpy));); Note that at the end, we have a "););". The file refuses to compile. Presumably, since SETITEM returns a value, wrapping the return value in a function call seems to be a reasonable thing to do. Would there be a problem in eliminating the semicolon and instead wrapping the entire function body in parenthesis? I noticed that GETITEM also ended in a semicolon, though I didn't have the same problem as above since Cython didn't automatically wrap it in a function call (I'm not even sure if it returns something). On a side note, is the above the best way (i.e., fastest way given an arbitrary numpy array) to set/get an element? Thanks, Jason

3 3

Re: [Numpy-discussion] F2PY errors still exist (possible solution)
by Blubaugh, David A. 26 Sep '08

26 Sep '08

To All, I can now see as to where the error lies. I apologize for my poor eye sight. The error lies in me using Compaq Visual Fortran 6.0. The error listed from f2py.py after I enter the following commands are the following: Commands Entered >>> C:\Python25\Scripts>C:\python25\python f2py.py -c --fcompiler=compaqv -m hello hello.f90 Error obtained >>> LINK: fatal error LNK1104: cannot open file "dformd.lib" Possible Solution >>> This error results from the Compaq Visual Fortran compiler not being installed with the proper file folder arrangement. The recommended file arrangement for the Compaq Visual Fortran compiler is as follows: Developer Studio Files: C:\Program Files\Microsoft Visual Studio\Common Visual Fortran Files: C:\Program Files\Microsoft Visual Studio\Df98 Shared Visual C++ Files: C:\Program Files\Microsoft Visual Studio\VC98 Should I just uninstall and then reinstall Compaq Visual Fortran 6.) to resolve this issue? Thanks, David Blubaugh -----Original Message----- From: Blubaugh, David A. Sent: Thursday, September 25, 2008 5:44 PM To: 'numpy-discussion(a)scipy.org' Subject: F2PY errors still exist To All, I am now trying to use the visual compaq compiler. I am legally required to utilize this compiler for my employment. I have tried the following: C:\Python25\Scripts>C:\python25\python f2py.py -c --fcompiler=compaqv -m hello hello.f90 I was wondering as to if I should input --compiler=msvc. If so, I am also obtaining an error with that as well. I will then obtain the following error!! I am now starting to becomed deeply concerned about F2PY's inability to generate any working executable or DLL files in capacity. The errors are as follows: running build running scons No module named msvccompiler in numpy.distutils; trying from distutils customize MSVCCompiler Found executable C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\bin\cl.e xe customize GnuFCompiler Could not locate executable g77 Found executable C:\Program Files\Microsoft Visual Studio\DF98\BIN\f77.exe gnu: no Fortran 90 compiler found gnu: no Fortran 90 compiler found Found executable C:\Program Files\Microsoft Visual Studio\DF98\BIN\f77.exe customize IntelVisualFCompiler Could not locate executable ifl customize AbsoftFCompiler Found executable C:\Program Files\Microsoft Visual Studio\DF98\BIN\f90.exe Found executable C:\Program Files\Microsoft Visual Studio\DF98\BIN\f90.exe customize CompaqVisualFCompiler Found executable C:\Program Files\Microsoft Visual Studio\DF98\BIN\DF.exe Found executable C:\Program Files\Microsoft Visual Studio\DF98\BIN\DF.exe customize CompaqVisualFCompiler No module named msvccompiler in numpy.distutils; trying from distutils customize MSVCCompiler Missing compiler_cxx fix for MSVCCompiler customize MSVCCompiler using scons running config_cc unifing config_cc, config, build_clib, build_ext, build commands --compiler opti ons running config_fc unifing config_fc, config, build_clib, build_ext, build commands --fcompiler opt ions running build_src building extension "hello" sources f2py options: [] f2py:> c:\docume~1\david\locals~1\temp\tmpmladol\src.win32-2.5\hellomodule.c creating c:\docume~1\david\locals~1\temp\tmpmladol creating c:\docume~1\david\locals~1\temp\tmpmladol\src.win32-2.5 Reading fortran codes... Reading file 'hello.f90' (format:free) Post-processing... Block: hello Block: foo Post-processing (stage 2)... Building modules... Building module "hello"... Constructing wrapper function "foo"... foo(a) Wrote C/API module "hello" to file "c:\docume~1\david\locals~1\temp\tmpm ladol\src.win32-2.5/hellomodule.c" adding 'c:\docume~1\david\locals~1\temp\tmpmladol\src.win32-2.5\fortranobject. c' to sources. adding 'c:\docume~1\david\locals~1\temp\tmpmladol\src.win32-2.5' to include_di rs. copying C:\python25\lib\site-packages\numpy\f2py\src\fortranobject.c -> c:\docum e~1\david\locals~1\temp\tmpmladol\src.win32-2.5 copying C:\python25\lib\site-packages\numpy\f2py\src\fortranobject.h -> c:\docum e~1\david\locals~1\temp\tmpmladol\src.win32-2.5 running build_ext No module named msvccompiler in numpy.distutils; trying from distutils customize MSVCCompiler customize MSVCCompiler using build_ext customize CompaqVisualFCompiler customize CompaqVisualFCompiler using build_ext building 'hello' extension compiling C sources creating c:\docume~1\david\locals~1\temp\tmpmladol\Release creating c:\docume~1\david\locals~1\temp\tmpmladol\Release\docume~1 creating c:\docume~1\david\locals~1\temp\tmpmladol\Release\docume~1\david creating c:\docume~1\david\locals~1\temp\tmpmladol\Release\docume~1\david\locals ~1 creating c:\docume~1\david\locals~1\temp\tmpmladol\Release\docume~1\david\locals ~1\temp creating c:\docume~1\david\locals~1\temp\tmpmladol\Release\docume~1\david\locals ~1\temp\tmpmladol creating c:\docume~1\david\locals~1\temp\tmpmladol\Release\docume~1\david\locals ~1\temp\tmpmladol\src.win32-2.5 C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\bin\cl.exe /c /nologo /Ox /MD /W3 /GX /DNDEBUG -Ic:\docume~1\david\locals~1\temp\tmpmladol\src.win32-2.5 -IC:\python25\lib\site-packages\numpy\core\include -IC:\python25\include -IC:\py thon25\PC /Tcc:\docume~1\david\locals~1\temp\tmpmladol\src.win32-2.5\hellomodule .c /Foc:\docume~1\david\locals~1\temp\tmpmladol\Release\docume~1\david\loca ls~1\ temp\tmpmladol\src.win32-2.5\hellomodule.obj Found executable C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\bin\cl.e xe C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\bin\cl.exe /c /nologo /Ox /MD /W3 /GX /DNDEBUG -Ic:\docume~1\david\locals~1\temp\tmpmladol\src.win32-2.5 -IC:\python25\lib\site-packages\numpy\core\include -IC:\python25\include -IC:\py thon25\PC /Tcc:\docume~1\david\locals~1\temp\tmpmladol\src.win32-2.5\fortranobje ct.c /Foc:\docume~1\david\locals~1\temp\tmpmladol\Release\docume~1\david\loca ls~ 1\temp\tmpmladol\src.win32-2.5\fortranobject.obj compiling Fortran sources Fortran f77 compiler: C:\Program Files\Microsoft Visual Studio\DF98\BIN\DF.exe / f77rtl /fixed /nologo /MD /WX /iface=(cref,nomixed_str_len_arg) /names:lowercase /assume:underscore /Ox /fast /optimize:5 /unroll:0 /math_library:fast /threads Fortran f90 compiler: C:\Program Files\Microsoft Visual Studio\DF98\BIN\DF.exe / nologo /MD /WX /iface=(cref,nomixed_str_len_arg) /names:lowercase /assume:unders core /Ox /fast /optimize:5 /unroll:0 /math_library:fast /threads Fortran fix compiler: C:\Program Files\Microsoft Visual Studio\DF98\BIN\DF.exe / fixed /nologo /MD /WX /iface=(cref,nomixed_str_len_arg) /names:lowercase /assume :underscore /Ox /fast /optimize:5 /unroll:0 /math_library:fast /threads compile options: '-Ic:\docume~1\david\locals~1\temp\tmpmladol\src.win32-2.5 -IC: \python25\lib\site-packages\numpy\core\include -IC:\python25\include -IC:\python 25\PC -c' DF.exe:f90: hello.f90 C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\bin\link.exe /DLL /nologo /INCREMENTAL:NO /LIBPATH:C:\python25\libs /LIBPATH:C:\python25\PCBuild /LIBPATH :C:\python25\libs /LIBPATH:C:\python25\PCBuild /EXPORT:inithello c:\docume~1\dav id\locals~1\temp\tmpmladol\Release\docume~1\david\locals~1\temp\tmpmlado l\src.wi n32-2.5\hellomodule.obj c:\docume~1\david\locals~1\temp\tmpmladol\Release\docume ~1\david\locals~1\temp\tmpmladol\src.win32-2.5\fortranobject.obj c:\docume~1\dav id\locals~1\temp\tmpmladol\Release\hello.o /OUT:.\hello.pyd /IMPLIB:c:\docume~1\ david\locals~1\temp\tmpmladol\Release\docume~1\david\locals~1\temp\tmpml adol\src .win32-2.5\hello.lib Found executable C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\bin\link .exe LINK : fatal error LNK1104: cannot open file 'dformd.lib' error: Command "C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\bin\link. exe /DLL /nologo /INCREMENTAL:NO /LIBPATH:C:\python25\libs /LIBPATH:C:\python25\ PCBuild /LIBPATH:C:\python25\libs /LIBPATH:C:\python25\PCBuild /EXPORT:inithello c:\docume~1\david\locals~1\temp\tmpmladol\Release\docume~1\david\locals~ 1\temp\ tmpmladol\src.win32-2.5\hellomodule.obj c:\docume~1\david\locals~1\temp\tmpmlado l\Release\docume~1\david\locals~1\temp\tmpmladol\src.win32-2.5\fortranob ject.obj c:\docume~1\david\locals~1\temp\tmpmladol\Release\hello.o /OUT:.\hello.pyd /IMP LIB:c:\docume~1\david\locals~1\temp\tmpmladol\Release\docume~1\david\loc als~1\te mp\tmpmladol\src.win32-2.5\hello.lib" failed with exit status 1104 C:\Python25\Scripts> This e-mail transmission contains information that is confidential and may be privileged. It is intended only for the addressee(s) named above. If you receive this e-mail in error, please do not read, copy or disseminate it in any manner. If you are not the intended recipient, any disclosure, copying, distribution or use of the contents of this information is prohibited. Please reply to the message immediately by informing the sender that the message was misdirected. After replying, please erase it from your computer system. Your assistance in correcting this error is appreciated.

1 0

Standard functions (z-score) on nan (again)
by Peter Saffrey 26 Sep '08

26 Sep '08

I've bodged my way through my median problems (see previous postings). Now I need to take a z-score of an array that might contain nans. At the moment, if the array, which is 7000 elements, contains 1 nan or more, all the results come out as nan. My other problem is that my array is indexed from somewhere else - position 0 holds the value for a particular id, position 1 holds the value for a particular id and so on, so if I remove the nans, all the indices are messed up. Can anybody suggest a sensible fix for this problem? I know I should really be using masked arrays, but I can't seem to find a masked-array version of zs. Is there one? Peter

2 1

F2PY errors still exist
by Blubaugh, David A. 26 Sep '08

26 Sep '08

To All, I am now trying to use the visual compaq compiler. I am legally required to utilize this compiler for my employment. I have tried the following: C:\Python25\Scripts>C:\python25\python f2py.py -c --fcompiler=compaqv -m hello hello.f90 I was wondering as to if I should input --compiler=msvc. If so, I am also obtaining an error with that as well. I will then obtain the following error!! I am now starting to becomed deeply concerned about F2PY's inability to generate any working executable or DLL files in capacity. The errors are as follows: running build running scons No module named msvccompiler in numpy.distutils; trying from distutils customize MSVCCompiler Found executable C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\bin\cl.e xe customize GnuFCompiler Could not locate executable g77 Found executable C:\Program Files\Microsoft Visual Studio\DF98\BIN\f77.exe gnu: no Fortran 90 compiler found gnu: no Fortran 90 compiler found Found executable C:\Program Files\Microsoft Visual Studio\DF98\BIN\f77.exe customize IntelVisualFCompiler Could not locate executable ifl customize AbsoftFCompiler Found executable C:\Program Files\Microsoft Visual Studio\DF98\BIN\f90.exe Found executable C:\Program Files\Microsoft Visual Studio\DF98\BIN\f90.exe customize CompaqVisualFCompiler Found executable C:\Program Files\Microsoft Visual Studio\DF98\BIN\DF.exe Found executable C:\Program Files\Microsoft Visual Studio\DF98\BIN\DF.exe customize CompaqVisualFCompiler No module named msvccompiler in numpy.distutils; trying from distutils customize MSVCCompiler Missing compiler_cxx fix for MSVCCompiler customize MSVCCompiler using scons running config_cc unifing config_cc, config, build_clib, build_ext, build commands --compiler opti ons running config_fc unifing config_fc, config, build_clib, build_ext, build commands --fcompiler opt ions running build_src building extension "hello" sources f2py options: [] f2py:> c:\docume~1\david\locals~1\temp\tmpmladol\src.win32-2.5\hellomodule.c creating c:\docume~1\david\locals~1\temp\tmpmladol creating c:\docume~1\david\locals~1\temp\tmpmladol\src.win32-2.5 Reading fortran codes... Reading file 'hello.f90' (format:free) Post-processing... Block: hello Block: foo Post-processing (stage 2)... Building modules... Building module "hello"... Constructing wrapper function "foo"... foo(a) Wrote C/API module "hello" to file "c:\docume~1\david\locals~1\temp\tmpm ladol\src.win32-2.5/hellomodule.c" adding 'c:\docume~1\david\locals~1\temp\tmpmladol\src.win32-2.5\fortranobject. c' to sources. adding 'c:\docume~1\david\locals~1\temp\tmpmladol\src.win32-2.5' to include_di rs. copying C:\python25\lib\site-packages\numpy\f2py\src\fortranobject.c -> c:\docum e~1\david\locals~1\temp\tmpmladol\src.win32-2.5 copying C:\python25\lib\site-packages\numpy\f2py\src\fortranobject.h -> c:\docum e~1\david\locals~1\temp\tmpmladol\src.win32-2.5 running build_ext No module named msvccompiler in numpy.distutils; trying from distutils customize MSVCCompiler customize MSVCCompiler using build_ext customize CompaqVisualFCompiler customize CompaqVisualFCompiler using build_ext building 'hello' extension compiling C sources creating c:\docume~1\david\locals~1\temp\tmpmladol\Release creating c:\docume~1\david\locals~1\temp\tmpmladol\Release\docume~1 creating c:\docume~1\david\locals~1\temp\tmpmladol\Release\docume~1\david creating c:\docume~1\david\locals~1\temp\tmpmladol\Release\docume~1\david\locals ~1 creating c:\docume~1\david\locals~1\temp\tmpmladol\Release\docume~1\david\locals ~1\temp creating c:\docume~1\david\locals~1\temp\tmpmladol\Release\docume~1\david\locals ~1\temp\tmpmladol creating c:\docume~1\david\locals~1\temp\tmpmladol\Release\docume~1\david\locals ~1\temp\tmpmladol\src.win32-2.5 C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\bin\cl.exe /c /nologo /Ox /MD /W3 /GX /DNDEBUG -Ic:\docume~1\david\locals~1\temp\tmpmladol\src.win32-2.5 -IC:\python25\lib\site-packages\numpy\core\include -IC:\python25\include -IC:\py thon25\PC /Tcc:\docume~1\david\locals~1\temp\tmpmladol\src.win32-2.5\hellomodule .c /Foc:\docume~1\david\locals~1\temp\tmpmladol\Release\docume~1\david\loca ls~1\ temp\tmpmladol\src.win32-2.5\hellomodule.obj Found executable C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\bin\cl.e xe C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\bin\cl.exe /c /nologo /Ox /MD /W3 /GX /DNDEBUG -Ic:\docume~1\david\locals~1\temp\tmpmladol\src.win32-2.5 -IC:\python25\lib\site-packages\numpy\core\include -IC:\python25\include -IC:\py thon25\PC /Tcc:\docume~1\david\locals~1\temp\tmpmladol\src.win32-2.5\fortranobje ct.c /Foc:\docume~1\david\locals~1\temp\tmpmladol\Release\docume~1\david\loca ls~ 1\temp\tmpmladol\src.win32-2.5\fortranobject.obj compiling Fortran sources Fortran f77 compiler: C:\Program Files\Microsoft Visual Studio\DF98\BIN\DF.exe / f77rtl /fixed /nologo /MD /WX /iface=(cref,nomixed_str_len_arg) /names:lowercase /assume:underscore /Ox /fast /optimize:5 /unroll:0 /math_library:fast /threads Fortran f90 compiler: C:\Program Files\Microsoft Visual Studio\DF98\BIN\DF.exe / nologo /MD /WX /iface=(cref,nomixed_str_len_arg) /names:lowercase /assume:unders core /Ox /fast /optimize:5 /unroll:0 /math_library:fast /threads Fortran fix compiler: C:\Program Files\Microsoft Visual Studio\DF98\BIN\DF.exe / fixed /nologo /MD /WX /iface=(cref,nomixed_str_len_arg) /names:lowercase /assume :underscore /Ox /fast /optimize:5 /unroll:0 /math_library:fast /threads compile options: '-Ic:\docume~1\david\locals~1\temp\tmpmladol\src.win32-2.5 -IC: \python25\lib\site-packages\numpy\core\include -IC:\python25\include -IC:\python 25\PC -c' DF.exe:f90: hello.f90 C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\bin\link.exe /DLL /nologo /INCREMENTAL:NO /LIBPATH:C:\python25\libs /LIBPATH:C:\python25\PCBuild /LIBPATH :C:\python25\libs /LIBPATH:C:\python25\PCBuild /EXPORT:inithello c:\docume~1\dav id\locals~1\temp\tmpmladol\Release\docume~1\david\locals~1\temp\tmpmlado l\src.wi n32-2.5\hellomodule.obj c:\docume~1\david\locals~1\temp\tmpmladol\Release\docume ~1\david\locals~1\temp\tmpmladol\src.win32-2.5\fortranobject.obj c:\docume~1\dav id\locals~1\temp\tmpmladol\Release\hello.o /OUT:.\hello.pyd /IMPLIB:c:\docume~1\ david\locals~1\temp\tmpmladol\Release\docume~1\david\locals~1\temp\tmpml adol\src .win32-2.5\hello.lib Found executable C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\bin\link .exe LINK : fatal error LNK1104: cannot open file 'dformd.lib' error: Command "C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\bin\link. exe /DLL /nologo /INCREMENTAL:NO /LIBPATH:C:\python25\libs /LIBPATH:C:\python25\ PCBuild /LIBPATH:C:\python25\libs /LIBPATH:C:\python25\PCBuild /EXPORT:inithello c:\docume~1\david\locals~1\temp\tmpmladol\Release\docume~1\david\locals~ 1\temp\ tmpmladol\src.win32-2.5\hellomodule.obj c:\docume~1\david\locals~1\temp\tmpmlado l\Release\docume~1\david\locals~1\temp\tmpmladol\src.win32-2.5\fortranob ject.obj c:\docume~1\david\locals~1\temp\tmpmladol\Release\hello.o /OUT:.\hello.pyd /IMP LIB:c:\docume~1\david\locals~1\temp\tmpmladol\Release\docume~1\david\loc als~1\te mp\tmpmladol\src.win32-2.5\hello.lib" failed with exit status 1104 C:\Python25\Scripts> This e-mail transmission contains information that is confidential and may be privileged. It is intended only for the addressee(s) named above. If you receive this e-mail in error, please do not read, copy or disseminate it in any manner. If you are not the intended recipient, any disclosure, copying, distribution or use of the contents of this information is prohibited. Please reply to the message immediately by informing the sender that the message was misdirected. After replying, please erase it from your computer system. Your assistance in correcting this error is appreciated.

1 0

numpy.complex* functions do not call the __complex__ method
by jason-sage＠creativetrax.com 26 Sep '08

26 Sep '08

In creating an array of type numpy.complex128, I'm having problems passing in Sage types that should be considered complex numbers since they implement the standard __complex__ method. However, numpy doesn't recognize that. Here's a minimal example: In [1]: class MyNum: ...: def __complex__(self): ...: return complex(1,3) ...: ...: In [2]: import numpy In [3]: a=MyNum() In [4]: complex(a) Out[4]: (1+3j) In [5]: numpy.complex128(a) --------------------------------------------------------------------------- <type 'exceptions.AttributeError'> Traceback (most recent call last) /home/jason/download/numpy/numpy-1.1.0/src/numpy/<ipython console> in <module>() <type 'exceptions.AttributeError'>: MyNum instance has no attribute '__float__' This is with numpy 1.1. Is this a bug, or is this by design? Thanks, Jason

2 2

A basic question about swig and Numeric
by Michel Dupront 26 Sep '08

26 Sep '08

Hello, I am trying to use Numeric and swig but it seems that there are few points that I don't understand. The only excuse I have is that I am new to these tools. I have a simple example that I cannot make work the way I would like. I have a c++ function that take as argument a std::vector. >From python I want to call the c++ function with an array object. For that purpose I want to write a typemap. Here is what was supposed to be a very simple example. example.h: #include #include void globale_print(std::vector vint) { std::cout<<"globale print vecteur: "; for (size_t i=0; i { PyArrayObject* aa=(PyArrayObject *) $input; $1.resize(aa->dimensions[0]); for (unsigned int i=0; idimensions[0]; i++) { $1[i]= *(int *) (aa->data + i* aa->strides[0] ); } }; %include "example.h" runme.py: import example import Numeric array=Numeric.array(range(5)) print array print type(array) example.globale_print(array) Like it is, it works. But there are a lot of things that I don't understand. For example if I want to check aa, like: """ if (!PyArray_Check(aa)) { return NULL; } """ the compilation of the wrapper is ok but when I run the python script runme.py, I have a segmentation fault because of the first line. Here I really need help. Please keep in mind that it is my first try to make a typemap .... Thanks a lot Michel _________________________________________________________________ Installez gratuitement les 20 émôticones Windows Live Messenger les plus fous ! Cliquez ici ! http://www.emoticones-messenger.fr/

4 4

Re: [Numpy-discussion] 1.2.0rc2 tagged! --PLEASE TEST--
by jh＠physics.ucf.edu 26 Sep '08

26 Sep '08

I hope you'll grab the updated docstrings before tagging. At least grab numpy.__doc__. The main numpy help string didn't adequately point users to alternatives to help() for the ufuncs. --jh--

2 1

how to test if index-tuple is "contained" in tuple of slice objects
by Sebastian Haase 25 Sep '08

25 Sep '08

Hi, Is there a good way to test that e.g. (2,3) is "contained" in [:,3] { == (slice(None), 3) } but not in [:,2] ? Background: I have an nd-image "2d section" viewer that supports line graphics overlays. Currently I can assign a tuple of ints to a given graphic, so that the lines are only shown when the respective 2d-section is displayed. I would like to extend this to support tuples such as (2,slice(None)) to show the graphics for "all z sections" at time 2, assuming the axis order to be time,z,y,x. Thanks for any help, Sebastian Haase

1 0

take a numpy
by Dinesh B Vadhia 25 Sep '08

25 Sep '08

I'm using numpy take() to pickout elements from a (1xM) array A indicated by the index numbers in indices ie. B = A.take(indices = list_indexes) It work perfectly but as A is large the performance isn't great and was wondering if there are faster methods available or ways to improve the use of take()? Dinesh

2 1

inserting indexes into an array
by Thomas Heller 24 Sep '08

24 Sep '08

I have a numpy array comtaining numbers (a, b, ...), like this: array([a, b, c, d, e, f]) What is the fastest way to create another array that has the index of the element before each element of the original array? The result should look like this: array([0, a, 1, b, 2, c, 3, d, 4, e, 5, f]) -- Thanks, Thomas

3 2