Mailman 3 July 2015 - SfePy

error run_tests.py in lubuntu15.04
by pyontaku14 22 Jul '15

22 Jul '15

Dear experts, I installed sfepy in lubuntu15.04. I tried ./run_tests.py --debug and encounterd the error as attached file. Could you tell me what to do for this error? Best regards, Takuo Fujita

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How to evaluate gradient at arbitrary point?
by Jozef Vesely 17 Jul '15

17 Jul '15

Hello, after much trying I figured I need your help. I managed to calculate the scalar field variable using sfepy field = Field.from_args('fu', np.float64, 'scalar', omega, space='H1', poly_space_base='lagrange', approx_order=2) u = FieldVariable('u', 'unknown', field) ... I can evaluate it at arbitrary points using probes or directly: p = zeros((500,2)) p[:,0] = linspace(-10,10,500) u.evaluate_at(p) Now I need the gradient, I don't want the average cell value as I am using it to integrate particle path through the field. This is what I tried: vecfield = Field.from_args('fgradu', field.dtype, 'vector', field.region, space=field.space, poly_space_base=field.poly_space_base, approx_order=field.approx_order) gradu = FieldVariable('gradu', 'parameter', vecfield, primary_var_name='(set-to-None)') from sfepy.discrete.fem.geometry_element import geometry_data gdata = geometry_data['2_3'] nc = len(gdata.coors) ivn = Integral('ivn', 'custom', gdata.coors, [gdata.volume / nc] * nc) d = u.evaluate('grad', integral=i) gradu.set_data_from_qp(d, i) Now I can use gradu.evaluate_at(p), however it is not precise. Even (u.evaluate_at(x+dx)-u.evaluate_at(x))/dx is better. I suspect some interpolation is still going on. I thought the special Integral I got from one of the examples was supposed to eliminate the interpolation. Where is the catch? Thanks for help Jozef

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Determine closest point in the mesh
by Jonatan Lehtonen 10 Jul '15

10 Jul '15

Hi there, Given a point outside a (2D) mesh, is there a way to find the closest point in the mesh? The goal is to implement extrapolation by evaluating at the closest point instead, since regular extrapolation would not produce acceptable results. Alternately, I can of course implement this myself, in which case I'd need to know/confirm a few things about how SfePy meshes work. Do I recall correctly that SfePy only supports linear elements (i.e. a second-order element has the same shape as a first-order elements)? And is there a clean/fast way of determining which elements contain a given mesh node? My plan would be something like this: 1) Given a point, find the n closest nodes in the mesh. 2) Determine every element in the mesh which contains at least one of these nodes. 3) For each element, determine the closest point in that element (which is easy if elements are linear), and then take the closest of all these points. If I go down this road, is there also a clean way of evaluating a variable in a given element? Of course I can just use the standard PointsProbe-approach, which shouldn't be much of a speed loss, it just seems silly to do this once the correct element is already known. Regards, Jonatan

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Linear_Homogenization Error - missing requirements
by Andy MacKrell 07 Jul '15

07 Jul '15

Hello again. I'm trying to run the base example for "Linear Homogenization" and "Linear Homogenization Up" and am getting the following error. Traceback (most recent call last): File "./simple.py", line 155, in <module> main() File "./simple.py", line 143, in main define_args=options.define_args) File "c:\Users\MultiMechanics\Documents\sfepy-master\sfepy\base\conf.py", line 381, in from_file_and_options override=override, setup=setup) File "c:\Users\MultiMechanics\Documents\sfepy-master\sfepy\base\conf.py", line 367, in from_file override=override, setup=setup) File "c:\Users\MultiMechanics\Documents\sfepy-master\sfepy\base\conf.py", line 413, in __init__ required=required, other=other) File "c:\Users\MultiMechanics\Documents\sfepy-master\sfepy\base\conf.py", line 423, in setup self.validate(required=required, other=other) File "c:\Users\MultiMechanics\Documents\sfepy-master\sfepy\base\conf.py", line 469, in validate raise ValueError('required missing: %s' % required_missing) ValueError: required missing: ['equations'] I can see in the requirements dictionary, the equations item is properly set 'equations' : equation_corrs I tried adding a null equations variable to the input file, but then got a different error AttributeError: 'Variables' object has no attribute 'di' I insert that attribute into the Variables dict and again get another, different error. I suppose I can continue to satisfy these requirements with null values, but I'm wondering if I'm doing something wrong off the get-go. Is there a newer version of these homogenization files that I may be missing. Thanks in advance for the help.

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Exit Status 1 Build Error - Windows8 - Python 2.7
by Andy MacKrell 07 Jul '15

07 Jul '15

I'm running Python 2.7 - 64 bit on Win8. I''m trying to build the C libraries using the following commands, but am running in to an error. python setup.py clean --all python setup.py build_ext --inplace --compiler=mingw32 The compiler is recognized properly and the build seems to be moving along. Then I hit this issue: Found executable C:\MinGW\bin\g++.exe C:\Python27\libs/libpython27.a(dmmes00976.o):(.idata$7+0x0): undefined reference to `_head_C__build27_cpython_PCBuild_libpython27_a' C:\Python27\libs/libpython27.a(dmmes00253.o):(.idata$7+0x0): undefined reference to `_head_C__build27_cpython_PCBuild_libpython27_a' C:\Python27\libs/libpython27.a(dmmes00245.o):(.idata$7+0x0): undefined reference to `_head_C__build27_cpython_PCBuild_libpython27_a' C:\Python27\libs/libpython27.a(dmmes01033.o):(.idata$7+0x0): undefined reference to `_head_C__build27_cpython_PCBuild_libpython27_a' C:\Python27\libs/libpython27.a(dmmes01035.o):(.idata$7+0x0): undefined reference to `_head_C__build27_cpython_PCBuild_libpython27_a' C:\Python27\libs/libpython27.a(dmmes01026.o):(.idata$7+0x0): more undefined refe rences to `_head_C__build27_cpython_PCBuild_libpython27_a' follow collect2.exe: error: ld returned 1 exit status error: Command "g++ -shared build\temp.win32-2.7\Release\sfepy\discrete\fem\extm ods\_fmfield.o -LC:\Python27\libs -LC:\Python27\PCbuild -Lbuild\temp.win32-2.7 - lsfepy_common -lpython27 -lmsvcr90 -o sfepy\discrete\fem\extmods\_fmfield.pyd" f ailed with exit status 1 When I run tests, I get 103/114 fails. I followed the instructions for Windows installation here: http://sfepy.org/doc-devel/installation.html

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preliminary support for parallel computing
by Robert Cimrman 03 Jul '15

03 Jul '15

FYI: It is still a work in progress, but SfePy can now be used to assemble and solve problems in parallel, using PETSc, see [1]. r. [1] http://sfepy.org/doc-devel/users_guide.html#solving-problems-in-parallel

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