Mailman 3 March 2009 - SciPy-User

Help required regding Eigenvectors
by Sudheer Phani 14 Mar '22

14 Mar '22

Hello All, I have been encountering some strange problems with the calculation of eigen vectors using python. The problem is with the sign of the eigen vectors calculated. On Very few occasions the eigen vectors calculated using python have an opposite sign than the actual eigenvectors, though the magnitude is correct. Can any one of you plz help me in this regard and suggest me some solution if you have encoutered similar problems . Any help in this regd is appreciated Thanks in Advace regds Sudheer

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pupynere/scipy.io.netcdf
by Ryan May 06 Mar '13

06 Mar '13

Hi, Anyone know if pupynere (a version of which is in scipy.io.netcdf) supports writing files with 64-bit offsets? This allows writing files larger than 2GB. Ryan -- Ryan May Graduate Research Assistant School of Meteorology University of Oklahoma

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scipy/numpy on CentOS 5/ Dependency problem
by Matthias Blaicher 08 Dec '10

08 Dec '10

Hello, I want to install SciPy and numpy on a CentOS 5 system. It contains a fresh install with up-to-date packages. I use the "official" Suse Build repos by DavidCournapeau. It fails with a conflict between refblas3 and blas. [root@localhost yum.repos.d]# yum install python-numpy python-scipy Loading "fastestmirror" plugin Loading mirror speeds from cached hostfile * home_ashigabou: download.opensuse.org * extras: mirrors.tummy.com * updates: dds.gina.alaska.edu * base: mirror.hmc.edu * addons: mirrors.tummy.com extras 100% |=========================| 1.1 kB 00:00 updates 100% |=========================| 951 B 00:00 base 100% |=========================| 1.1 kB 00:00 addons 100% |=========================| 951 B 00:00 Setting up Install Process Parsing package install arguments Resolving Dependencies --> Running transaction check ---> Package python-scipy.i386 0:0.6.0-2.1 set to be updated --> Processing Dependency: libblas.so.3 for package: python-scipy --> Processing Dependency: libblas.so.3 for package: python-scipy --> Processing Dependency: liblapack.so.3 for package: python-scipy --> Processing Dependency: libgfortran.so.1 for package: python-scipy --> Processing Dependency: liblapack.so.3 for package: python-scipy ---> Package python-numpy.i386 0:1.2.0-1.1 set to be updated --> Processing Dependency: gcc-gfortran for package: python-numpy --> Processing Dependency: refblas3 for package: python-numpy --> Processing Dependency: lapack3 < 3.1 for package: python-numpy --> Running transaction check ---> Package gcc-gfortran.i386 0:4.1.2-42.el5 set to be updated --> Processing Dependency: gcc = 4.1.2-42.el5 for package: gcc-gfortran ---> Package blas.i386 0:3.0-37.el5 set to be updated ---> Package lapack3.i386 0:3.0-19.1 set to be updated ---> Package lapack.i386 0:3.0-37.el5 set to be updated ---> Package refblas3.i386 0:3.0-11.1 set to be updated ---> Package libgfortran.i386 0:4.1.2-42.el5 set to be updated --> Running transaction check ---> Package gcc.i386 0:4.1.2-42.el5 set to be updated --> Processing Dependency: libgomp.so.1 for package: gcc --> Processing Dependency: glibc-devel >= 2.2.90-12 for package: gcc --> Processing Dependency: libgomp = 4.1.2-42.el5 for package: gcc --> Running transaction check ---> Package glibc-devel.i386 0:2.5-24 set to be updated --> Processing Dependency: glibc-headers for package: glibc-devel --> Processing Dependency: glibc-headers = 2.5-24 for package: glibc-devel ---> Package libgomp.i386 0:4.1.2-42.el5 set to be updated --> Running transaction check ---> Package glibc-headers.i386 0:2.5-24 set to be updated --> Processing Dependency: kernel-headers for package: glibc-headers --> Processing Dependency: kernel-headers >= 2.2.1 for package: glibc-headers --> Running transaction check ---> Package kernel-headers.i386 0:2.6.18-92.1.13.el5 set to be updated --> Processing Conflict: refblas3 conflicts blas --> Finished Dependency Resolution Error: refblas3 conflicts with blas Is there anything I'm doing wrong here, as I don't want to compile all dependencies by myself.. Sincerly, Matthias Blaicher

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3D plotting
by Robert Cimrman 10 Sep '09

10 Sep '09

Hi, I need to do some simple 3D plots, so I tried the two Cookbook recipes (xplt, mplot3d) and failed: * xplt: does not work when using a custom installation directory such as python setup.py install --root=/home/share/software apparently the gistdata directory path is wrong: gist.error: failed to create drawing -- Gist work.gs style sheet missing * mplot3d: does not work with my version of matplotlib (0.80). I have made the changes mentioned in the Cookbook to no avail. (Axes.__init__() args apparently changed, as well as some other matplotlib object attributes) Any ideas? mplot3d looks great, I would really like to use it! thanks, r.

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assign to diagonal values?
by Carlos Scheidegger 07 Jul '09

07 Jul '09

Say I have a matrix m whose diagonal values I want to replace with the contents of vector new_diagonal. Right now, I'm using m -= diag(m) m += diag(new_diagonal) but that seems pretty wasteful (especially if diag() creates new arrays, which I suspect it does). Is there a standard (or any efficient) way to assign the diagonal values directly without an explicit for loop? Googling for "site:www.scipy.org assign diagonal" only returned results for sparse matrices, which is not the case here - these are plain numpy arrays. Thanks in advance, -carlos

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scipy.signal.firwin
by Jan Rauberg 19 May '09

19 May '09

I'm missing the functionality of firwin like in matlab/octave fir1, so that I can give a 'low', 'high' and 'stop' option. I don't know how to create a FIR window based high pass filter. Or is there something planned for the future? Thank you Jan

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Is numpy's argsort lying about its numpy.int32 types?
by Rob Clewley 15 May '09

15 May '09

Hi, I'm having a problem comparing some types when using numpy's argsort. I'm using numpy 1.0.2. I can reproduce it simply: Python 2.4.4 (#71, Oct 18 2006, 08:34:43) [MSC v.1310 32 bit (Intel)] << snip >> In [1]: from numpy import argsort, sort, int32, array In [2]: x=array([1,3,2]) In [3]: aa=argsort(x) In [4]: as=sort(x) In [5]: type(aa[0]) Out[5]: <type 'numpy.int32'> In [6]: type(as[0]) Out[6]: <type 'numpy.int32'> In [7]: int32 Out[7]: <type 'numpy.int32'> In [8]: type(as[0])==int32 Out[8]: True In [9]: type(aa[0])==int32 Out[9]: False Any of the three indices in aa give me the same problem. Can someone explain if I should be doing this a different way, and if this is a bug?! Thanks, Rob

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Automating Matlab
by Eric Schug 28 Apr '09

28 Apr '09

Is there strong interest in automating matlab to numpy conversion? I have a working version of a matlab to python translator. It allows translation of matlab scripts into numpy constructs, supporting most of the matlab language. The parser is nearly complete. Most of the remaining work involves providing a robust translation. Such as * making sure that copies on assign are done when needed. * correct indexing a(:) becomes a.flatten(1) when on the left hand side (lhs) of equals and a[:] when on the right hand side I've seen a few projects attempt to do this, but for one reason or another have stopped it.

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fourier series
by vvinuv 16 Apr '09

16 Apr '09

Hi I would like to demonstrate the fourier series graphically. I have a function in an array and want to decompose it. I used rfft to do that. But I am not able to interpret the coefficients I am getting. How can I use the array returns by rfft in the fourier series, ie how can I extract the coefficients (a_0, a_1, b_1, a_2, b_2 etc.) out of that? Thanks Vinu -- View this message in context: http://www.nabble.com/fourier-series-tp22776639p22776639.html Sent from the Scipy-User mailing list archive at Nabble.com.

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JOB: write numpy docs
by Joe Harrington 15 Apr '09

15 Apr '09

Last year's Doc Marathon got us off to a great start on documenting NumPy! But, there's still much work to be done, and SciPy after that. It's time to gear up for doing it again. Critical to last year's success was Stefan van der Walt's committed time, but he will be unable to play that role this year. So, I am looking to hire someone to write NumPy docs and help coordinate the doc project and its volunteers. The job includes working with me, the doc team, doc volunteers, and developers to: write and review a lot of docs, mainly those that others don't want to write help define milestones organize campaigns and volunteer teams to meet them research the NumPy and SciPy source codes to help plan: the eventual SciPy documentation the writing of a good User Manual work with the packaging team to meet their release deadlines perform other duties as assigned I am seeking someone to work full time if possible, and at least half time, from mid-April (or soon thereafter) through at least the (northern) summer. Candidates must be experienced NumPy and SciPy programmers; familiarity under the hood is a strong plus. They must also demonstrate their ability to produce excellent docs on the docs.SciPy.org wiki. Having contributed at a high level to an open-source community, especially to SciPy, is a big plus. Ability to take direction, work with and lead a team, and to work for extended periods without direct supervision on a list of assigned tasks are all critical. The applicant must be able to function well in a Linux environment; familiarity with multiple platforms is a plus. Please reply directly to me by email only. Include the following (PDF or ASCII formats strongly preferred): CV Statement of interest, qualifications per requirements above, availability, and wage expectations. Contact info for at least 3 professional references. Links to doc wiki pages for which you wrote the initial draft Links to doc wiki pages started by others to which you contributed significantly (edited, reviewed, proofed) The position is open until filled; candidates with complete applications by April 15 will receive full consideration. This is an open posting. Candidates who have not written any pages on the doc wiki yet have several weeks in which to do so. Pay will be commensurate with experience (up to a point). Relocation is not necessary. Candidates will need to provide their own computer and internet access. The University of Central Florida is an equal opportunity, equal access, affirmative action employer. --jh-- Prof. Joseph Harrington Department of Physics MAP 414 4000 Central Florida Blvd. University of Central Florida Orlando, FL 32816-2385 (407) 823-3416 voice (407) 823-5112 fax (407) 823-2325 physics office jh(a)physics.ucf.edu

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