Mailman 3 September 2003 - SciPy-User

ActiveState Python
by Robert Ferrell Sept. 19, 2003

Sept. 19, 2003

I'd like to try ActiveState's Visual Python plug-in for Visual Studio ..NET. However, AS says that it only works with Active State's Python. I'm not sure why that is. However, would that preclude use of SciPy? I'm using Windows, and would really like to avoid building SciPy myself. Downloading the Sumo SciPy binary file is so painless for me. thanks, -robert

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Matlab's orth module
by Nils Wagner Sept. 19, 2003

Sept. 19, 2003

Dear experts, Is it somehow possible to realize Matlab's orth function in scipy ? Range space of a matrix Syntax B = orth(A) Description B = orth(A) returns an orthonormal basis for the range of A. The columns of B span the same space as the columns of A, and the columns of B are orthogonal, so that B'*B = eye(rank(A)). The number of columns of B is the rank of A. A small example would be appreciated. Thanks in advance Nils

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Scipy's orth is more reliable
by Nils Wagner Sept. 19, 2003

Sept. 19, 2003

Hi all, It seems to me, that scipy's orth module is more reliable than the one, which comes with MLab2.py. . http://pdilib.sourceforge.net/MLab2.py Nils

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Fwd: [SANDPYT] Reminder - San Diego Python meeting tonight
by Chuck Esterbrook Sept. 18, 2003

Sept. 18, 2003

--- Original Message --- From: "Joshua Penix" <jpenix(a)binarytribe.com> Sent: Thu, 18 Sep 2003 10:58:57 -0700 Subject: [SANDPYT] Reminder - San Diego Python meeting tonight > The San Diego Python Users' group is having its monthly meeting > tonight. The topic will be wxPython (http://www.wxpython.org/), a > Python binding to the wxWindows cross-platform GUI toolkit > (http://www.wxwindows.org/). > > The meeting will be held at the San Diego County of Education > complex in Linda vista, in room 306: > > > San Diego County Office of Education > 6401 Linda Vista Road > San Diego, CA > > > Doors open at 6:30PM, meeting starts at 7. > > > For more information, visit SANDPYT's homepage: > http://www.sandpyt.org > > Also a quick reminder that SANDPYT unfortunately lost its mailing > list membership, so if you were subscribed prior to September 8, > 2003, you will need to resubscribe. If you weren't subscribed, now > is the time to do so! :^) > > > http://www.sandpyt.org/mailman/listinfo/sandpyt > > > --Josh > > > _______________________________________________ > SANDPYT mailing list > SANDPYT(a)sandpyt.org > http://www.sandpyt.org/mailman/listinfo/sandpyt

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Double integration using gaussian quadrature query
by David Unitt Sept. 18, 2003

Sept. 18, 2003

Dear SciPy Users, I would be very grateful of your help, I am trying to do a double integral using Gaussian quadrature, I have put the code at the bottom of this message, along with the output. The problem I have is that if the function 'integrand' returns a value calculated using 'a0' the program throws up the exception "ValueError: frames are not aligned". 'a0' starts out as the integration variable 'a' in function 'integral2'. I have traced the problem to the successive calls of function 'integral1' from 'integral2'. Each time this happens the variable 'aa' in 'integral1' gains an element. Specifying aa[0] doesn't work. Any help on how to get round this would be appreciated Thanks david --------CODE------- #!/usr/bin/env python #################################################################### #calculating a double integral with fixed variable # #################################################################### from Numeric import * from __future__ import division from scipy import integrate ####################### #define integrand def integrand(b0,a0,c0): print "integrand called" return a0*b0*b0*c0 #If this contains a0 the program crashes #calculate the double integral def integral1(aa,b1,b2,c): print "integral1 called" print "aa = ",aa x1 = integrate.quadrature(lambda b: integrand(b,aa,c), b1, b2) return x1[0] def integral2(a1,a2,b1,b2,c): #a1, a2 are limits of this integral, b1,b2 are limits for 'integral1' #c is some constant print "integral2 called" x2 = integrate.quadrature(lambda a: integral1(a,b1,b2,c), a1, a2) return x2 ## f = integral2(0.0,1.0,0.0,1.0,1.0) print f[0] -----OUTPUT-------- integral2 called integral1 called aa = [ 0.5+0.j] integrand called integrand called integrand called Took 4 points. integral1 called aa = [ 0.21132487+0.j 0.78867513+0.j] integrand called integrand called Took 3 points. integral1 called aa = [ 0.11270167+0.j 0.5 +0.j 0.88729833+0.j] integrand called integrand called Traceback (most recent call last): File "C:/quad_test2.py", line 37, in ? f = integral2(0.0,1.0,0.0,1.0,1.0) File "C:/quad_test2.py", line 32, in integral2 x2 = integrate.quadrature(lambda a: integral1(a,b1,b2,c), a1, a2) File "C:\PROGRA~1\python22\Lib\site-packages\scipy\integrate\quadrature.py", line 65, in quadrature newval = fixed_quad(func,a,b,args,n)[0] File "C:\PROGRA~1\python22\Lib\site-packages\scipy\integrate\quadrature.py", line 35, in fixed_quad return (b-a)/2.0*sum(w*func(y,*args)), None File "C:/quad_test2.py", line 32, in <lambda> x2 = integrate.quadrature(lambda a: integral1(a,b1,b2,c), a1, a2) File "C:/quad_test2.py", line 24, in integral1 x1 = integrate.quadrature(lambda b: integrand(b,aa,c), b1, b2) File "C:\PROGRA~1\python22\Lib\site-packages\scipy\integrate\quadrature.py", line 65, in quadrature newval = fixed_quad(func,a,b,args,n)[0] File "C:\PROGRA~1\python22\Lib\site-packages\scipy\integrate\quadrature.py", line 35, in fixed_quad return (b-a)/2.0*sum(w*func(y,*args)), None File "C:/quad_test2.py", line 24, in <lambda> x1 = integrate.quadrature(lambda b: integrand(b,aa,c), b1, b2) File "C:/quad_test2.py", line 18, in integrand return a0*b0*b0*c0 #If this contains a) the program crashes ValueError: frames are not aligned _____________________________________________________________________ This e-mail has been scanned for viruses by MCI's Internet Managed Scanning Services - powered by MessageLabs. For further information visit http://www.mci.com

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[weave] newbie : compilation issue
by Jean-Baptiste Richet - AREAS Sept. 18, 2003

Sept. 18, 2003

Hi, I'm trying to have weave take my C functions into Python. I try to build a module with ext_tools, but I don't know much about writing Python extensions (actually, nothing). I just try to guess how to do from the tutorial and its examples. But of course it doesn't work. First, let me give you the error message: ============================= jb@areas:~/routines/commun$ python ext_date.py /home/jb/routines/commun/date_ext.cpp: In function `struct PyObject * c_positionne_flot(PyObject *, PyObject *, PyObject *)': /home/jb/routines/commun/date_ext.cpp:925: `raw_locals' undeclared (first use this function) /home/jb/routines/commun/date_ext.cpp:925: (Each undeclared identifier is reported only once /home/jb/routines/commun/date_ext.cpp:925: for each function it appears in.) /home/jb/routines/commun/date_ext.cpp:925: `raw_globals' undeclared (first use this function) /home/jb/routines/commun/date_ext.cpp:925: implicit declaration of function `int get_variable(...)' Traceback (most recent call last): File "ext_date.py", line 50, in ? build_date() File "ext_date.py", line 45, in build_date module.compile() File "/usr/local/lib/python2.3/site-packages/weave/ext_tools.py", line 349, in compile verbose = verbose, **kw) File "/usr/local/lib/python2.3/site-packages/weave/build_tools.py", line 194, in build_extension setup(name = module_name, ext_modules = [ext],verbose=verb) File "/usr/local/lib/python2.3/distutils/core.py", line 166, in setup raise SystemExit, "error: " + str(msg) weave.build_tools.CompileError: error: command 'gcc' failed with exit status 1 jb@areas:~/routines/commun$ ==================================== Maybe I lack some #include or something like that ? The line : PyObject* py_file = get_variable("fichier_src",raw_locals,raw_globals); from which the error is raised, was found in the weave tutorial about file conversions. I can hardly understand what it does. Here is the code at the bottom of the message. [I hesitate to give the date.c code, or the date_ext.cpp code, it's a bit long, and there's no compile error from it. If you need it to help me, please tell me.] thanks for your help, JBR ================ ext_date.py ========================= # -*- coding: UTF-8 -*- #test d'utilisation de weave pour créer une bibliothèque from weave import ext_tools fichier_date_c = open('date.c','r') code_date_c = fichier_date_c.read() fichier_src = fichier_date_c fichier_log = open('log.log','w') pdt = 'a' date = 1.23 def build_date(): """contruit le module d'extension """ module = ext_tools.ext_module('date_ext') #fonction de positionnement dans un fichier """ positionne_flot a 4 arguments, un p_pointeur de fichier en lecture, un p_pointeur de fichier en écriture (log), un caractère et une date (double) """ ext_code = """ PyObject* py_file = get_variable("fichier_src",raw_locals,raw_globals); FILE* file = py_to_file(py_file,"fichier_src"); PyObject* py_log = get_variable("fichier_log",raw_locals,raw_globals); FILE* log = py_to_file(py_log,"fichier_log"); FILE** p_file = &file; FILE** p_log = &log; char c_pdt = std::string(pdt).c_str()[0]; int resultat; resultat = positionne_flot(p_file,c_pdt,date,p_log); return_val = Py::new_reference_to(Py::Int(resultat)); """ fonction = ext_tools.ext_function('c_positionne_flot',ext_code,['fichier_src','pdt','date','fichier_log']) fonction.customize.add_support_code(code_date_c) module.add_function(fonction) module.compile() try: import date_ext except ImportError: build_date() import date_ext ============================================= -- Jean-Baptiste Richet AREAS _________________________________ Association régionale pour l'étude et l'amélioration des sols 2, avenue Foch 76460 Saint Valéry en Caux tél : +33 2 35 97 25 12 fax : +33 2 35 97 25 73 _________________________________

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Double integration using gaussian quadrature query
by David Unitt Sept. 17, 2003

Sept. 17, 2003

Dear SciPy Users, I would be very grateful of your help, I am trying to do a double integral using Gaussian quadrature, I have put the code at the bottom of this message, along with the output. The problem I have is that if the function 'integrand' returns a value calculated using 'a0' the program throws up the exception "ValueError: frames are not aligned". 'a0' starts out as the integration variable 'a' in function 'integral2'. I have traced the problem to the successive calls of function 'integral1' from 'integral2'. Each time this happens the variable 'aa' in 'integral1' gains an element. Specifying aa[0] doesn't work. Any help on how to get round this would be appreciated Thanks david --------CODE------- #!/usr/bin/env python #################################################################### #calculating a double integral with fixed variable # #################################################################### from Numeric import * from __future__ import division from scipy import integrate ####################### #define integrand def integrand(b0,a0,c0): print "integrand called" #print a0 return a0*b0*b0*c0 #If this contains a) the program crashes #calculate the double integral def integral1(aa,b1,b2,c): print "integral1 called" print "aa = ",aa x1 = integrate.quadrature(lambda b: integrand(b,aa,c), b1, b2) return x1[0] def integral2(a1,a2,b1,b2,c): #a1, a2 are limits of this integral, b1,b2 are limits for 'integral1' #c is some constant print "integral2 called" x2 = integrate.quadrature(lambda a: integral1(a,b1,b2,c), a1, a2) return x2 ## f = integral2(0.0,1.0,0.0,1.0,1.0) print f[0] -----OUTPUT-------- integral2 called integral1 called aa = [ 0.5+0.j] integrand called integrand called integrand called Took 4 points. integral1 called aa = [ 0.21132487+0.j 0.78867513+0.j] integrand called integrand called Took 3 points. integral1 called aa = [ 0.11270167+0.j 0.5 +0.j 0.88729833+0.j] integrand called integrand called Traceback (most recent call last): File "C:/quad_test2.py", line 37, in ? f = integral2(0.0,1.0,0.0,1.0,1.0) File "C:/quad_test2.py", line 32, in integral2 x2 = integrate.quadrature(lambda a: integral1(a,b1,b2,c), a1, a2) File "C:\PROGRA~1\python22\Lib\site-packages\scipy\integrate\quadrature.py", line 65, in quadrature newval = fixed_quad(func,a,b,args,n)[0] File "C:\PROGRA~1\python22\Lib\site-packages\scipy\integrate\quadrature.py", line 35, in fixed_quad return (b-a)/2.0*sum(w*func(y,*args)), None File "C:/quad_test2.py", line 32, in <lambda> x2 = integrate.quadrature(lambda a: integral1(a,b1,b2,c), a1, a2) File "C:/quad_test2.py", line 24, in integral1 x1 = integrate.quadrature(lambda b: integrand(b,aa,c), b1, b2) File "C:\PROGRA~1\python22\Lib\site-packages\scipy\integrate\quadrature.py", line 65, in quadrature newval = fixed_quad(func,a,b,args,n)[0] File "C:\PROGRA~1\python22\Lib\site-packages\scipy\integrate\quadrature.py", line 35, in fixed_quad return (b-a)/2.0*sum(w*func(y,*args)), None File "C:/quad_test2.py", line 24, in <lambda> x1 = integrate.quadrature(lambda b: integrand(b,aa,c), b1, b2) File "C:/quad_test2.py", line 18, in integrand return a0*b0*b0*c0 #If this contains a) the program crashes ValueError: frames are not aligned _____________________________________________________________________ This e-mail has been scanned for viruses by MCI's Internet Managed Scanning Services - powered by MessageLabs. For further information visit http://www.mci.com

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Grids
by Nils Wagner Sept. 16, 2003

Sept. 16, 2003

Dear experts, Let us consider a polygon in the complex plane, whose vertices are \xi_1=-10-10j, \xi_2=10-10j, \xi_3=10+10j,\xi_4=-10+10j, \xi_5 \equiv \xi_1 How can I discretize the domain (enclosed by the polygon) with scipy ? A small example would be appreciated. Thanks in advance. Nils

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Contour plots in scipy
by Nils Wagner Sept. 16, 2003

Sept. 16, 2003

Dear experts, I am interested in a plot of equipotential curves. If desired, the regions between contours should be shaded or colored to indicate their magnitude. Is this feature already available in scipy ? Any comments or suggestions ? Nils

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error building scipy
by Rob van Putten Sept. 16, 2003

Sept. 16, 2003

Hi there, I get an error when building SciPy on Slackware 9.0 The error occurs during 'python setup.py build' at the command: g77 -shared build/temp.linux-i586-2.2/fortranobject.o build/temp.linux-i586-2.2/fblasmodule.o -Lbuild/temp.linux-i586-2.2 -Lbuild/temp.linux-i586-2.2 -lfblas_f2py -llapack_src -lblas_src -lg2c -o build/lib.linux-i586-2.2/scipy/linalg/fblas.so and it says ld: cannot open crtbeginS.o: no such file or directory error... Any idea what could be wrong? Thanks in advance, Rob --here is the start of the output in case it is helpful-- ### Little Endian detected #### atlas_info: NOT AVAILABLE blas_info: NOT AVAILABLE blas_src_info: FOUND: sources = ['/tmp/blas/caxpy.f', '/tmp/blas/csscal.f', '/tmp/blas/dnrm2 ... ... tmp/blas/zgemm.f', '/tmp/blas/zsymm.f', '/tmp/blas/ztrsm.f'] lapack_info: NOT AVAILABLE lapack_src_info: FOUND: sources = ['/tmp/lapack/sbdsdc.f', '/tmp/lapack/sbdsqr.f', '/tmp/lapac ... ... k/scsum1.f', '/tmp/lapack/izmax1.f', '/tmp/lapack/dzsum1.f'] ### Little Endian detected #### fftw_info: FOUND: libraries = ['rfftw', 'fftw'] library_dirs = ['/usr/local/lib'] define_macros = [('SCIPY_FFTW_H', None)] include_dirs = ['/usr/local/include'] djbfft_info: NOT AVAILABLE DJBFFT (http://cr.yp.to/djbfft.html) libraries not found. Directories to search for the libraries can be specified in the scipy_distutils/site.cfg file (section [djbfft]) or by setting the DJBFFT environment variable.

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