You can subscribe to this list here.
2010 
_{Jan}

_{Feb}

_{Mar}

_{Apr}

_{May}

_{Jun}

_{Jul}

_{Aug}

_{Sep}

_{Oct}
(1) 
_{Nov}
(1) 
_{Dec}


2011 
_{Jan}

_{Feb}

_{Mar}
(1) 
_{Apr}

_{May}
(1) 
_{Jun}
(9) 
_{Jul}
(2) 
_{Aug}
(6) 
_{Sep}
(11) 
_{Oct}
(15) 
_{Nov}
(4) 
_{Dec}
(9) 
2012 
_{Jan}
(7) 
_{Feb}
(14) 
_{Mar}
(11) 
_{Apr}

_{May}

_{Jun}
(3) 
_{Jul}

_{Aug}

_{Sep}

_{Oct}

_{Nov}
(3) 
_{Dec}

2013 
_{Jan}
(8) 
_{Feb}

_{Mar}
(1) 
_{Apr}
(3) 
_{May}

_{Jun}

_{Jul}
(3) 
_{Aug}
(2) 
_{Sep}

_{Oct}

_{Nov}

_{Dec}
(4) 
2014 
_{Jan}

_{Feb}

_{Mar}

_{Apr}

_{May}
(2) 
_{Jun}
(2) 
_{Jul}

_{Aug}

_{Sep}

_{Oct}

_{Nov}

_{Dec}

From: Rafael Vázquez <vazquez@im...>  20140607 15:13:08

Dear Andrea, you need to update the function sp_nurbs_2d, that you can find in the repository: http://sourceforge.net/p/geopdes/code/HEAD/tree/trunk/ I'll try to make a release soon to fix these small bugs. Regards, Rafa > > > Dear GEOPDEs Authors, > > I'm trying to use GEOPDEs to solve the Bilaplace problem in the square. > I have a problem with the boundary conditions in > "solve_bilaplace_2d_iso.m". > The code of the example : > > % EX_BILAPLACE_ISO_SQUARE: solve the Bilaplace problem in the square, > discretized with NURBS (isoparametric approach). > > % The function solves the bilaplacian problem > % > % laplace( epsilon(x) laplace(u)) = f in Omega = F((0,1)^2) > % du/dn = 0 on Gamma_D > % u = 0 on Gamma_D > % > % with a variational formulation based on the Laplacian, that is, > % > % (epsilon laplace(u), laplace(v)) = (f,v) > % > > % 1) PHYSICAL DATA OF THE PROBLEM > clear problem_data > % Physical domain, defined as NURBS map given in a text file > problem_data.geo_name = 'geo_square.txt'; > > % Type of boundary conditions for each side of the domain > problem_data.nmnn_sides = []; > problem_data.drchlt_sides = [1 2 3 4]; > > % Physical parameters(c=epsilon) > problem_data.c_diff = @(x, y) ones(size(x)); > > % Source and boundary terms > problem_data.f = @(x, y) > 4*(pi^4)*(cos(2.*pi.*x)2*cos(2.*pi.*(xy))+cos(2.*pi.*y)2*cos(2.*pi.*(x+y))); > > problem_data.h = @(x, y, ind) zeros (size (x)); > > > % Exact solution (optional) > problem_data.uex = @(x, y) (sin(pi.*x).^2).*(sin(pi.*y).^2); > problem_data.graduex = @(x, y) cat (1, ... > reshape (2*sin(pi.*x).*pi.*cos(pi.*x).*(sin(pi.*y).^2), > [1, size(x)]), ... > reshape (2*(sin(pi.*x).^2).*pi.*cos(pi.*y).*sin(pi.*y), > [1, size(x)])); > > > % 2) CHOICE OF THE DISCRETIZATION PARAMETERS > clear method_data > method_data.degree = [3 3]; % Degree of the splines > method_data.regularity = [2 2]; % Regularity of the splines > method_data.nsub = [20 20]; % Number of subdivisions > method_data.nquad = [6 6]; % Points for the Gaussian quadrature > rule > > % 3) CALL TO THE SOLVER > [geometry, msh, space, u] = solve_bilaplace_2d_iso (problem_data, > method_data); > > > > % 4) POSTPROCESSING > % 4.1) EXPORT TO PARAVIEW > > output_file = 'Squarebilaplace_NRB_Deg3_Reg2_Sub9_1'; > > vtk_pts = {linspace(0, 1, 20), linspace(0, 1, 20)}; > fprintf ('The result is saved in the file %s \n \n', output_file); > sp_to_vtk (u, space, geometry, vtk_pts, output_file, 'u') > > % 4.2) PLOT IN MATLAB. COMPARISON WITH THE EXACT SOLUTION > > [eu, F] = sp_eval (u, space, geometry, vtk_pts); > [X, Y] = deal (squeeze(F(1,:,:)), squeeze(F(2,:,:))); > subplot (1,2,1) > surf (X, Y, eu) > title ('Numerical solution'), axis tight > subplot (1,2,2) > surf (X, Y, problem_data.uex (X,Y)) > title ('Exact solution'), axis tight > > % Display errors of the computed solution in the L2 and H1 norm > [error_h1, error_l2] = ... > sp_h1_error (space, msh, u, problem_data.uex, > problem_data.graduex) > > Evaluating the code, I get the following error message: > > Error using subsref > Reference to nonexistent field 'adjacent_dofs'. > > Error in sp_nurbs_2d/subsref (line 3) > value = builtin ('subsref', obj, S); > > Error in solve_bilaplace_2d_iso (line 100) > drchlt_dofs_r = union (drchlt_dofs_r, > space.boundary(iside).adjacent_dofs); > > > How can I resolve this problem? > > Thank you, > > Andrea Giorgini > > > >  > Learn Graph Databases  Download FREE O'Reilly Book > "Graph Databases" is the definitive new guide to graph databases and their > applications. Written by three acclaimed leaders in the field, > this first edition is now available. Download your free book today! > http://p.sf.net/sfu/NeoTech > _______________________________________________ > Geopdesusers mailing list > Geopdesusers@... > https://lists.sourceforge.net/lists/listinfo/geopdesusers > 
From: Andrea Giorgini <andrea.giorgini@ma...>  20140607 09:29:05

Dear GEOPDEs Authors, I'm trying to use GEOPDEs to solve the Bilaplace problem in the square. I have a problem with the boundary conditions in "solve_bilaplace_2d_iso.m". The code of the example : % EX_BILAPLACE_ISO_SQUARE: solve the Bilaplace problem in the square, discretized with NURBS (isoparametric approach). % The function solves the bilaplacian problem % % laplace( epsilon(x) laplace(u)) = f in Omega = F((0,1)^2) % du/dn = 0 on Gamma_D % u = 0 on Gamma_D % % with a variational formulation based on the Laplacian, that is, % % (epsilon laplace(u), laplace(v)) = (f,v) % % 1) PHYSICAL DATA OF THE PROBLEM clear problem_data % Physical domain, defined as NURBS map given in a text file problem_data.geo_name = 'geo_square.txt'; % Type of boundary conditions for each side of the domain problem_data.nmnn_sides = []; problem_data.drchlt_sides = [1 2 3 4]; % Physical parameters(c=epsilon) problem_data.c_diff = @(x, y) ones(size(x)); % Source and boundary terms problem_data.f = @(x, y) 4*(pi^4)*(cos(2.*pi.*x)2*cos(2.*pi.*(xy))+cos(2.*pi.*y)2*cos(2.*pi.*(x+y))); problem_data.h = @(x, y, ind) zeros (size (x)); % Exact solution (optional) problem_data.uex = @(x, y) (sin(pi.*x).^2).*(sin(pi.*y).^2); problem_data.graduex = @(x, y) cat (1, ... reshape (2*sin(pi.*x).*pi.*cos(pi.*x).*(sin(pi.*y).^2), [1, size(x)]), ... reshape (2*(sin(pi.*x).^2).*pi.*cos(pi.*y).*sin(pi.*y), [1, size(x)])); % 2) CHOICE OF THE DISCRETIZATION PARAMETERS clear method_data method_data.degree = [3 3]; % Degree of the splines method_data.regularity = [2 2]; % Regularity of the splines method_data.nsub = [20 20]; % Number of subdivisions method_data.nquad = [6 6]; % Points for the Gaussian quadrature rule % 3) CALL TO THE SOLVER [geometry, msh, space, u] = solve_bilaplace_2d_iso (problem_data, method_data); % 4) POSTPROCESSING % 4.1) EXPORT TO PARAVIEW output_file = 'Squarebilaplace_NRB_Deg3_Reg2_Sub9_1'; vtk_pts = {linspace(0, 1, 20), linspace(0, 1, 20)}; fprintf ('The result is saved in the file %s \n \n', output_file); sp_to_vtk (u, space, geometry, vtk_pts, output_file, 'u') % 4.2) PLOT IN MATLAB. COMPARISON WITH THE EXACT SOLUTION [eu, F] = sp_eval (u, space, geometry, vtk_pts); [X, Y] = deal (squeeze(F(1,:,:)), squeeze(F(2,:,:))); subplot (1,2,1) surf (X, Y, eu) title ('Numerical solution'), axis tight subplot (1,2,2) surf (X, Y, problem_data.uex (X,Y)) title ('Exact solution'), axis tight % Display errors of the computed solution in the L2 and H1 norm [error_h1, error_l2] = ... sp_h1_error (space, msh, u, problem_data.uex, problem_data.graduex) Evaluating the code, I get the following error message: Error using subsref Reference to nonexistent field 'adjacent_dofs'. Error in sp_nurbs_2d/subsref (line 3) value = builtin ('subsref', obj, S); Error in solve_bilaplace_2d_iso (line 100) drchlt_dofs_r = union (drchlt_dofs_r, space.boundary(iside).adjacent_dofs); How can I resolve this problem? Thank you, Andrea Giorgini 
From: Rafael Vazquez <vazquez@im...>  20140530 08:24:24

Dear Rahul, I really don't see the point on solving the discrete problem without using matlab (or octave, which is free), but if you want to do it, you can compute the equation of the piecewise polynomials using the CoxDe Boor formula, and then compute the integrals by hand to get the stiffness matrix and the righthand side. You can even use symbolic computations for those. Regards, Rafa Il 27/05/2014 10:40, rahul yadav ha scritto: > can anyone guide me to solve a problem using isogeometric analysis > theoretically without using matlab. The problem is > (d^2u/dx^2)u+x^2=0 for 0<x<1 > boundary condition u(0)=0, u(1)=0 > I want to solve it using quadratic NURBS with knot vector [0 0 0 0.25 0.5 > 0.75 1 1 1]. >  > The best possible search technologies are now affordable for all companies. > Download your FREE open source Enterprise Search Engine today! > Our experts will assist you in its installation for $59/mo, no commitment. > Test it for FREE on our Cloud platform anytime! > http://pubads.g.doubleclick.net/gampad/clk?id=145328191&iu=/4140/ostg.clktrk > _______________________________________________ > Geopdesusers mailing list > Geopdesusers@... > https://lists.sourceforge.net/lists/listinfo/geopdesusers 
From: rahul yadav <rahulyadav1002@gm...>  20140527 08:40:18

can anyone guide me to solve a problem using isogeometric analysis theoretically without using matlab. The problem is (d^2u/dx^2)u+x^2=0 for 0<x<1 boundary condition u(0)=0, u(1)=0 I want to solve it using quadratic NURBS with knot vector [0 0 0 0.25 0.5 0.75 1 1 1]. 
From: Rafael Vázquez <vazquez@im...>  20131221 23:56:55

Dear Naim, I'm sorry, but I have not used Rhino for a long time, and I don't remember how it was done. Maybe some other user can help you with this. Regards, Rafa > Hello, > > I am using Rhino autodesk tspline plugin. Can you please tell me how to > set > the boundary nodes in Rhino so that I can use the file file for analysis > creating iga extension file. > > Thanks in advance. > > Best regards, > Naim > > > > > >  > Md.Naim Hossain > Research fellow > inuTech GmbH > Nuremberg, Germany. > Phone:+4917687963582 >  > Rapidly troubleshoot problems before they affect your business. Most IT > organizations don't have a clear picture of how application performance > affects their revenue. With AppDynamics, you get 100% visibility into your > Java,.NET, & PHP application. Start your 15day FREE TRIAL of AppDynamics > Pro! > http://pubads.g.doubleclick.net/gampad/clk?id=84349831&iu=/4140/ostg.clktrk > _______________________________________________ > Geopdesusers mailing list > Geopdesusers@... > https://lists.sourceforge.net/lists/listinfo/geopdesusers > 
From: Md Naim Hossain <md.naimhossain11@gm...>  20131219 14:49:49

Hello, I am using Rhino autodesk tspline plugin. Can you please tell me how to set the boundary nodes in Rhino so that I can use the file file for analysis creating iga extension file. Thanks in advance. Best regards, Naim  Md.Naim Hossain Research fellow inuTech GmbH Nuremberg, Germany. Phone:+4917687963582 
From: Rafael Vazquez <vazquez@im...>  20131205 12:35:32

Dear Naim, at this moment the only possibility for local refinement in GeoPDEs is to use the Bezier extraction files from the Tsplines plugin for Rhino. There is nothing for PHTsplines. Best regards, Rafa Il 05/12/2013 11:39, Md Naim Hossain ha scritto: > Hi, > > Is there anything so far developed with PHT(polynomial spline over > hierarchical tmeshes) spline based isogeometric analysis in GeoPDEs? If so > then please kindly let me know. Thanks in advance and have a nice day. > > Best regards, > Naim >  > Sponsored by Intel(R) XDK > Develop, test and display web and hybrid apps with a single code base. > Download it for free now! > http://pubads.g.doubleclick.net/gampad/clk?id=111408631&iu=/4140/ostg.clktrk > _______________________________________________ > Geopdesusers mailing list > Geopdesusers@... > https://lists.sourceforge.net/lists/listinfo/geopdesusers 
From: Md Naim Hossain <md.naimhossain11@gm...>  20131205 10:39:45

Hi, Is there anything so far developed with PHT(polynomial spline over hierarchical tmeshes) spline based isogeometric analysis in GeoPDEs? If so then please kindly let me know. Thanks in advance and have a nice day. Best regards, Naim 
From: Rafael Vazquez <vazquez@im...>  20130826 08:48:35

Dear Sebastian, the example we had in mind was a different quadrature rule, where the elements for the numerical integration do not coincide with the knot spans. In this case the number of nonvanishing functions for some element may be greater than p+1. Regards, Rafa Il 23/08/2013 10:30, Sebastian Eiser ha scritto: > Dear Sirs, > > Thank you for providing the geoPDEs software. I'm reading parts of the code > you provided and was wondering if could explain one detail to me. > > In sp_bspline_1d_param, the variable nsh (number of shape functions) can > vary for the different columns in the array of quadrature nodes. > >> nsh(iel) = nnz (connectivity(:,iel)); > In all the simple examples I run, nsh will be always assigned p+1 (which I > expect), regardless of the column, i.e. all(nsh == nsh_max) > > I can't think of a case where this is not true. Could you provide a counter > example and/or an explanation for this code section? > > Thanks a lot, Sebastian >  > Introducing Performance Central, a new site from SourceForge and > AppDynamics. Performance Central is your source for news, insights, > analysis and resources for efficient Application Performance Management. > Visit us today! > http://pubads.g.doubleclick.net/gampad/clk?id=48897511&iu=/4140/ostg.clktrk > _______________________________________________ > Geopdesusers mailing list > Geopdesusers@... > https://lists.sourceforge.net/lists/listinfo/geopdesusers 
From: Sebastian Eiser <sebastian.eiser@st...>  20130823 09:04:11

Dear Sirs, Thank you for providing the geoPDEs software. I'm reading parts of the code you provided and was wondering if could explain one detail to me. In sp_bspline_1d_param, the variable nsh (number of shape functions) can vary for the different columns in the array of quadrature nodes. > nsh(iel) = nnz (connectivity(:,iel)); In all the simple examples I run, nsh will be always assigned p+1 (which I expect), regardless of the column, i.e. all(nsh == nsh_max) I can't think of a case where this is not true. Could you provide a counter example and/or an explanation for this code section? Thanks a lot, Sebastian 
From: Rafael Vazquez <vazquez@im...>  20130717 17:08:28

The plate with hole is already in the package, in the file "geo_plate_with_hole.txt". The parametrization is different from the one in the first paper on IGA, and is only C^0 along the diagonal line. For the ellipsoid, as Mike said you can simply scale the control points of the sphere. It is very easy to do it in the NURBS toolbox: you can define the sphere using nrbrevolve, and then scale it with nrbtform and vecscale. Rafa 
From: Mike Graham <mikegraham@gm...>  20130717 15:32:35

On Wed, Jul 17, 2013 at 10:46 AM, Mohammad Reza Zibaei <mrzibaei85@... > wrote: > Hi all, > > How can i find control points data (coordinates and weights) for an > elipsoid and > a plate with a circular hole? > I want to compare results of buckling problem about these shapes with > resault that investigated from meshfree method in this book : > '' Mesh free methods [ G. R. Liu]'' > Generally, how information over the more complex twodimensional shapes of > control is achieved? > > Thank you very much for your help. > > Regards, > Mohammad Reza > Check out "Isogeometric analysis: CAD, finite elements, NURBS, exact geometry and mesh refinement" by Hughes, Cottrell, and Bazilevs (2004) for the NURBS data for a plate with a hole. I'm pretty sure you can get an ellipsoid by just scaling the control point locations for a sphere. Mike 
From: Mohammad Reza Zibaei <mrzibaei85@gm...>  20130717 14:46:34

Hi all, How can i find control points data (coordinates and weights) for an elipsoid and a plate with a circular hole? I want to compare results of buckling problem about these shapes with resault that investigated from meshfree method in this book : '' Mesh free methods [ G. R. Liu]'' Generally, how information over the more complex twodimensional shapes of control is achieved? Thank you very much for your help. Regards, Mohammad Reza 
From: Rafael Vazquez <vazquez@im...>  20130423 13:49:01

Dear GeoPDEs users, we have included in GeoPDEs some functions for solving the bilaplacian problem in 2D, with new examples for Kirchhoff plates, everything written by Marco Pingaro. The new functions will be included in the next release of the geopdes_base and geopdes_elasticity packages. For the impatient, you can access them in the sourceforge repository: https://sourceforge.net/p/geopdes/code/HEAD/tree/trunk/ Regards, Rafael Vazquez 
From: Rafael Vazquez <vazquez@im...>  20130410 16:11:41

Dear Mengda, I've just uploaded the package to install GeoPDEs in the Octave mingw version for Windows. You can find the latest package here: https://sourceforge.net/projects/geopdes/files/Octave%20packages%20for%20Windows/ You should be able to install with method 1, that is pkg install geopdes_base2.0.3mingw.tar.gz If you have any problem just let me know. Best, Rafa Il 29/03/2013 16:44, Mengda Wu ha scritto: > Hi All, > > I was trying to the two install methods in README.txt on octave3.6.2 > mingw version. Neither one works. I am using windows XP 32bit OS. > > =================================================================================== > For the method 1: > pkg install geopdes_base<version>.tar.gz > pkg load geopdes_base > > I got > > octave:2> pkg install geopdes_base2.0.3.tar.gz > > gzip: stdout: Broken pipe > op_f_v.cc:20:21: 致命错误：geopdes.h：No such file or directory > 编译中断。 > g++: 错误：op_f_v.o：No such file or directory > make: *** [op_f_v.oct] Error 1 > 'make' returned the following error: make: Entering directory > `/tmp/oct2/geopdes_base/src' > mkoctfile > IC:\DOCUME~1\ABCu00\LOCALS~1\Temp\oct2\geopdes_base\inst\include op_f_v.cc > make: Leaving directory `/tmp/oct2/geopdes_base/src' > error: called from `pkg>configure_make' in file > C:\Octave\Octave3.6.2_gcc4.6.2\share\octave\3.6.2\m\pkg\pkg.m > near line 1385, column 9 > error: called from: > error: C:\Octave\Octave3.6.2_gcc4.6.2\share\octave\3.6.2\m\pkg\pkg.m at > line 827, column 5 > error: C:\Octave\Octave3.6.2_gcc4.6.2\share\octave\3.6.2\m\pkg\pkg.m at > line 383, column 9 > ================================================================================== > For method 2: > cd c:\tmp > mkdir c:\octavepackages > pkg prefix c:\octavepackages c:\octavepackages > system ("tar xzf geopdes_base<version>.tar.gz") > pkg install geopdes_base > > I got > octave:21> pkg install geopdes_base > unpack: FILETYPE must be gunzip for a directory > error: called from `unpack' in file > C:\Octave\Octave3.6.2_gcc4.6.2\share\octave\3.6.2\m\miscellaneous\unpack.m > near line 70, column 7 > error: called from: > error: C:\Octave\Octave3.6.2_gcc4.6.2\share\octave\3.6.2\m\pkg\pkg.m at > line 773, column 5 > error: C:\Octave\Octave3.6.2_gcc4.6.2\share\octave\3.6.2\m\pkg\pkg.m at > line 383, column 9 > > Can you help me? > > Thanks, > Mengda >  > Own the FutureIntel(R) Level Up Game Demo Contest 2013 > Rise to greatness in Intel's independent game demo contest. Compete > for recognition, cash, and the chance to get your game on Steam. > $5K grand prize plus 10 genre and skill prizes. Submit your demo > by 6/6/13. http://altfarm.mediaplex.com/ad/ck/12124176961303672 > _______________________________________________ > Geopdesusers mailing list > Geopdesusers@... > https://lists.sourceforge.net/lists/listinfo/geopdesusers > 
From: Rafael Vazquez <vazquez@im...>  20130402 08:38:05

Dear Mengda, several people had the same problem before. There is a package to install GeoPDEs in Octave using Windows in this direction. http://sourceforge.net/projects/geopdes/files/Octave%20packages%20for%20Windows/ Right now this is only for version 2.0.2, which does not work for the Tsplines plugin. I will upload the version 2.0.3 as soon as possible. Regards, Rafael Vazquez Il 29/03/2013 16:44, Mengda Wu ha scritto: > Hi All, > > I was trying to the two install methods in README.txt on octave3.6.2 > mingw version. Neither one works. I am using windows XP 32bit OS. > > =================================================================================== > For the method 1: > pkg install geopdes_base<version>.tar.gz > pkg load geopdes_base > > I got > > octave:2> pkg install geopdes_base2.0.3.tar.gz > > gzip: stdout: Broken pipe > op_f_v.cc:20:21: 致命错误：geopdes.h：No such file or directory > 编译中断。 > g++: 错误：op_f_v.o：No such file or directory > make: *** [op_f_v.oct] Error 1 > 'make' returned the following error: make: Entering directory > `/tmp/oct2/geopdes_base/src' > mkoctfile > IC:\DOCUME~1\ABCu00\LOCALS~1\Temp\oct2\geopdes_base\inst\include op_f_v.cc > make: Leaving directory `/tmp/oct2/geopdes_base/src' > error: called from `pkg>configure_make' in file > C:\Octave\Octave3.6.2_gcc4.6.2\share\octave\3.6.2\m\pkg\pkg.m > near line 1385, column 9 > error: called from: > error: C:\Octave\Octave3.6.2_gcc4.6.2\share\octave\3.6.2\m\pkg\pkg.m at > line 827, column 5 > error: C:\Octave\Octave3.6.2_gcc4.6.2\share\octave\3.6.2\m\pkg\pkg.m at > line 383, column 9 > ================================================================================== > For method 2: > cd c:\tmp > mkdir c:\octavepackages > pkg prefix c:\octavepackages c:\octavepackages > system ("tar xzf geopdes_base<version>.tar.gz") > pkg install geopdes_base > > I got > octave:21> pkg install geopdes_base > unpack: FILETYPE must be gunzip for a directory > error: called from `unpack' in file > C:\Octave\Octave3.6.2_gcc4.6.2\share\octave\3.6.2\m\miscellaneous\unpack.m > near line 70, column 7 > error: called from: > error: C:\Octave\Octave3.6.2_gcc4.6.2\share\octave\3.6.2\m\pkg\pkg.m at > line 773, column 5 > error: C:\Octave\Octave3.6.2_gcc4.6.2\share\octave\3.6.2\m\pkg\pkg.m at > line 383, column 9 > > Can you help me? > > Thanks, > Mengda >  > Own the FutureIntel(R) Level Up Game Demo Contest 2013 > Rise to greatness in Intel's independent game demo contest. Compete > for recognition, cash, and the chance to get your game on Steam. > $5K grand prize plus 10 genre and skill prizes. Submit your demo > by 6/6/13. http://altfarm.mediaplex.com/ad/ck/12124176961303672 > _______________________________________________ > Geopdesusers mailing list > Geopdesusers@... > https://lists.sourceforge.net/lists/listinfo/geopdesusers > 
From: Mengda Wu <phdggg@gm...>  20130329 15:44:09

Hi All, I was trying to the two install methods in README.txt on octave3.6.2 mingw version. Neither one works. I am using windows XP 32bit OS. =================================================================================== For the method 1: pkg install geopdes_base<version>.tar.gz pkg load geopdes_base I got octave:2> pkg install geopdes_base2.0.3.tar.gz gzip: stdout: Broken pipe op_f_v.cc:20:21: 致命错误：geopdes.h：No such file or directory 编译中断。 g++: 错误：op_f_v.o：No such file or directory make: *** [op_f_v.oct] Error 1 'make' returned the following error: make: Entering directory `/tmp/oct2/geopdes_base/src' mkoctfile IC:\DOCUME~1\ABCu00\LOCALS~1\Temp\oct2\geopdes_base\inst\include op_f_v.cc make: Leaving directory `/tmp/oct2/geopdes_base/src' error: called from `pkg>configure_make' in file C:\Octave\Octave3.6.2_gcc4.6.2\share\octave\3.6.2\m\pkg\pkg.m near line 1385, column 9 error: called from: error: C:\Octave\Octave3.6.2_gcc4.6.2\share\octave\3.6.2\m\pkg\pkg.m at line 827, column 5 error: C:\Octave\Octave3.6.2_gcc4.6.2\share\octave\3.6.2\m\pkg\pkg.m at line 383, column 9 ================================================================================== For method 2: cd c:\tmp mkdir c:\octavepackages pkg prefix c:\octavepackages c:\octavepackages system ("tar xzf geopdes_base<version>.tar.gz") pkg install geopdes_base I got octave:21> pkg install geopdes_base unpack: FILETYPE must be gunzip for a directory error: called from `unpack' in file C:\Octave\Octave3.6.2_gcc4.6.2\share\octave\3.6.2\m\miscellaneous\unpack.m near line 70, column 7 error: called from: error: C:\Octave\Octave3.6.2_gcc4.6.2\share\octave\3.6.2\m\pkg\pkg.m at line 773, column 5 error: C:\Octave\Octave3.6.2_gcc4.6.2\share\octave\3.6.2\m\pkg\pkg.m at line 383, column 9 Can you help me? Thanks, Mengda 
From: Rafael Vazquez <vazquez@im...>  20130122 09:47:37

Dear Marco, good, I'm glad to hear that it works. For your information, the function "op_u_v" computes the mass matrix also for elasticity. In fact, it works for 2D/3D, and for scalar or vectorial problems. Regards, Rafa Il 21/01/2013 22:10, Marco Brino ha scritto: > Dear Rafa, > > no problem, thank you for the response! > That was one of my problems, that having considered the weights in the > computation of the NURBS functions and derivatives, once I compute the > Jacobian matrix I need Cartesian coordinates. > Other problem I found myself, is the computation of the NURBS > derivatives itself: using the formula with the "squared sum" in the > denominator, this caused me numerical errors. Now I substituted it > with the one with the sum without the square elevation, and everything > works perfect. > > Just for information, I found that NASTRAN 8nodes brick uses > underintegration to manage shear locking, with also correction of > Poisson's ratio on the offdiagonal terms in the constitutive matrix. > > Now that my code works and after some tests I got interesting results, > efficiency, etc… maybe if you find it interesting we can try > implementing this modal analysis in GeoPDEs. If I'm right, I didn't > find the mass matrix computation in the elasticity toolbox! > > Thank you very much for the help! > > Kindest regards, > Marco > > 
From: Marco Brino <marco.brino@po...>  20130121 21:10:56

Dear Rafa, no problem, thank you for the response! That was one of my problems, that having considered the weights in the computation of the NURBS functions and derivatives, once I compute the Jacobian matrix I need Cartesian coordinates. Other problem I found myself, is the computation of the NURBS derivatives itself: using the formula with the "squared sum" in the denominator, this caused me numerical errors. Now I substituted it with the one with the sum without the square elevation, and everything works perfect. Just for information, I found that NASTRAN 8nodes brick uses underintegration to manage shear locking, with also correction of Poisson's ratio on the offdiagonal terms in the constitutive matrix. Now that my code works and after some tests I got interesting results, efficiency, etc… maybe if you find it interesting we can try implementing this modal analysis in GeoPDEs. If I'm right, I didn't find the mass matrix computation in the elasticity toolbox! Thank you very much for the help! Kindest regards, Marco On Jan 21, 2013, at 2:55 PM, Rafael Vazquez <vazquez@...> wrote: > Dear Marco, > sorry for the late response. For the weights in the control points, you > can use any of the two approaches: either use the Cartesian coordinates > and the weights separately, or use the homogeneous (weighted) > coordinates. The important thing is that, when you write your function > to compute/refine the geometry, you use that information in the correct > way. The second option is the one that is implemented in the NURBS > toolbox, following the algorithms in the NURBS Book by Piegl and Tiller. > In the book you can also find more explanations about the use of > homogeneous coordinates. I hope this is helpful. > > I have almost no experience with NASTRAN, so I don't know what could be > the difference. Maybe someone else in the list could help with this one. > > Regards, > Rafa > > > Il 17/01/2013 00:18, Marco Brino ha scritto: >> Hi all, >> >> I'm always trying to develop my own 3D IGA code, and I have a couple of >> questions: >>  when dealing with NURBS, which control point coordinates must be used, >> when computing the mapping between the physical domain and the >> parametric domain? I mean, the "original" coordinates, or the >> coordinates multiplied by the weights, like we have to do with the >> "nrbmak" function? >> >>  I understand that using linear Bspline functions causes the shape >> functions to be equal to the ones used by standard FEM. So also the >> stiffness matrix is equal to the one computed with standard FEM. So I >> tried to compare the stiffness matrix computed with GeoPDEs, with the >> one computed by NASTRAN, of a beam composed by 5 hexa8 elements. Well, I >> found that the matrices are sligthly different, so that GeoPDEs gives a >> stiffer matrix. >> I tried using my 3D IGA code and I obtained the same matrix of GeoPDEs. >> >> Did someone of you find similar differencies? >> >> Thank you very much in advance! >> >> Kindest regards, >> Marco >> >>  >> Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, >> MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current >> with LearnDevNow  3,200 stepbystep video tutorials by Microsoft >> MVPs and experts. ON SALE this month only  learn more at: >> http://p.sf.net/sfu/learnmore_122712 >> _______________________________________________ >> Geopdesusers mailing list >> Geopdesusers@... >> https://lists.sourceforge.net/lists/listinfo/geopdesusers >> > > >  > Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, > MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current > with LearnDevNow  3,200 stepbystep video tutorials by Microsoft > MVPs and experts. SALE $99.99 this month only  learn more at: > http://p.sf.net/sfu/learnmore_122412 > _______________________________________________ > Geopdesusers mailing list > Geopdesusers@... > https://lists.sourceforge.net/lists/listinfo/geopdesusers  Marco Brino Politecnico di Torino  DIGEP Corso Duca degli Abruzzi, 24 I10129 Torino, Italy +39 011 090 7205 +39 393 554 4537 marco.brino@... 
From: Rafael Vazquez <vazquez@im...>  20130121 13:55:42

Dear Marco, sorry for the late response. For the weights in the control points, you can use any of the two approaches: either use the Cartesian coordinates and the weights separately, or use the homogeneous (weighted) coordinates. The important thing is that, when you write your function to compute/refine the geometry, you use that information in the correct way. The second option is the one that is implemented in the NURBS toolbox, following the algorithms in the NURBS Book by Piegl and Tiller. In the book you can also find more explanations about the use of homogeneous coordinates. I hope this is helpful. I have almost no experience with NASTRAN, so I don't know what could be the difference. Maybe someone else in the list could help with this one. Regards, Rafa Il 17/01/2013 00:18, Marco Brino ha scritto: > Hi all, > > I'm always trying to develop my own 3D IGA code, and I have a couple of > questions: >  when dealing with NURBS, which control point coordinates must be used, > when computing the mapping between the physical domain and the > parametric domain? I mean, the "original" coordinates, or the > coordinates multiplied by the weights, like we have to do with the > "nrbmak" function? > >  I understand that using linear Bspline functions causes the shape > functions to be equal to the ones used by standard FEM. So also the > stiffness matrix is equal to the one computed with standard FEM. So I > tried to compare the stiffness matrix computed with GeoPDEs, with the > one computed by NASTRAN, of a beam composed by 5 hexa8 elements. Well, I > found that the matrices are sligthly different, so that GeoPDEs gives a > stiffer matrix. > I tried using my 3D IGA code and I obtained the same matrix of GeoPDEs. > > Did someone of you find similar differencies? > > Thank you very much in advance! > > Kindest regards, > Marco > >  > Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, > MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current > with LearnDevNow  3,200 stepbystep video tutorials by Microsoft > MVPs and experts. ON SALE this month only  learn more at: > http://p.sf.net/sfu/learnmore_122712 > _______________________________________________ > Geopdesusers mailing list > Geopdesusers@... > https://lists.sourceforge.net/lists/listinfo/geopdesusers > 
From: Marco Brino <marco.brino@po...>  20130116 23:20:34

Hi all, I'm always trying to develop my own 3D IGA code, and I have a couple of questions:  when dealing with NURBS, which control point coordinates must be used, when computing the mapping between the physical domain and the parametric domain? I mean, the "original" coordinates, or the coordinates multiplied by the weights, like we have to do with the "nrbmak" function?  I understand that using linear Bspline functions causes the shape functions to be equal to the ones used by standard FEM. So also the stiffness matrix is equal to the one computed with standard FEM. So I tried to compare the stiffness matrix computed with GeoPDEs, with the one computed by NASTRAN, of a beam composed by 5 hexa8 elements. Well, I found that the matrices are sligthly different, so that GeoPDEs gives a stiffer matrix. I tried using my 3D IGA code and I obtained the same matrix of GeoPDEs. Did someone of you find similar differencies? Thank you very much in advance! Kindest regards, Marco  Marco Brino Politecnico di Torino  DIGEP Corso Duca degli Abruzzi, 24 I10129 Torino, Italy +39 011 090 7205 +39 393 554 4537 marco.brino@... 
From: Marco Brino <marco.22@gm...>  20130116 23:19:15

Hi all, I'm always trying to develop my own 3D IGA code, and I have a couple of questions:  when dealing with NURBS, which control point coordinates must be used, when computing the mapping between the physical domain and the parametric domain? I mean, the "original" coordinates, or the coordinates multiplied by the weights, like we have to do with the "nrbmak" function?  I understand that using linear Bspline functions causes the shape functions to be equal to the ones used by standard FEM. So also the stiffness matrix is equal to the one computed with standard FEM. So I tried to compare the stiffness matrix computed with GeoPDEs, with the one computed by NASTRAN, of a beam composed by 5 hexa8 elements. Well, I found that the matrices are sligthly different, so that GeoPDEs gives a stiffer matrix. I tried using my 3D IGA code and I obtained the same matrix of GeoPDEs. Did someone of you find similar differencies? Thank you very much in advance! Kindest regards, Marco 
From: Marco Brino <marco.brino@po...>  20130114 11:30:20

Thank you Rafa, so you list the DoF by components, as I guessed. I know about the boundaries, and actually I have the problem of the incoherence of results AFTER I apply the symmetry. To do it, I do the same that in FEM is done with RBE2. Anyway, I was comparing both the versions with and without the glued boundaries. Thank you very much, I will try to fit with your listing order. Kindest regards, Marco On 14/01/2013 12:06, Rafael Vázquez wrote: > Dear Marco, > in GeoPDEs_elasticity the dofs for a vector component are listed > consecutively: assume that you have N dofs for the scalar problem, you > will have 3*N for the elasticity problem. The dofs for the first component > are 1:N, for the second they are N+1:2*N, and for the third 2*N+1:3*N. I'm > not sure to have understood correctly your ordering, but if your code is > implemented in a coherent way, this should not give any error. > > By the way, are you modelling the whole cylinder without symmetry? Because > a possible source of error is what you do at the boundaries. Notice that > when you apply the parametrization, two of the boundaries of the square > collapse into a single internal edge. You will have to set that the dofs > of both sides are the same, similar to what is done in multipatch. This > topic was already discussed in the mailing list. > > Regards, > Rafa > >> Hi all, >> >> I'm trying to build Matlab IGA own codes, just for having full knowledge >> and control of the relative routines. Obviously I use GeoPDEs as a >> reference for benchmark and results. >> >> In particular, I have a 3D hollow cylinder, and I'm trying to compute >> its modal analysis. I obtained strange results so i tried to compare my >> stiffness matrix with the one calculated by GeoPDEs. >> >> The layout of the matrices appears very different, and this could be >> related to the order of the DoF are listed. >> >> In my code, they are: >>  u_1x >>  u_1y >>  u_1z >>  u_2x >>  u_2y >>  u_2z >>  ... >> >> Which is the order of the DoF in the e lasticity package of GeoPDEs? >> >> Thank you very much for the help! >> >> Kindest regards, >> Marco >> >>  >> Marco Brino >> Politecnico di Torino  DIGEP >> Corso Duca degli Abruzzi, 24 >> I10129 Torino, Italy >> +39 011 090 7205 >> +39 393 554 4537 >> marco.brino@... >> >> >>  >> Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, >> MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current >> with LearnDevNow  3,200 stepbystep video tutorials by Microsoft >> MVPs and experts. SALE $99.99 this month only  learn more at: >> http://p.sf.net/sfu/learnmore_122412 >> _______________________________________________ >> Geopdesusers mailing list >> Geopdesusers@... >> https://lists.sourceforge.net/lists/listinfo/geopdesusers >> >  Marco Brino Politecnico di Torino  DIGEP Corso Duca degli Abruzzi, 24 I10129 Torino, Italy +39 011 090 7205 +39 393 554 4537 marco.brino@... 
From: Rafael Vázquez <vazquez@im...>  20130114 11:27:58

Dear Marco, in GeoPDEs_elasticity the dofs for a vector component are listed consecutively: assume that you have N dofs for the scalar problem, you will have 3*N for the elasticity problem. The dofs for the first component are 1:N, for the second they are N+1:2*N, and for the third 2*N+1:3*N. I'm not sure to have understood correctly your ordering, but if your code is implemented in a coherent way, this should not give any error. By the way, are you modelling the whole cylinder without symmetry? Because a possible source of error is what you do at the boundaries. Notice that when you apply the parametrization, two of the boundaries of the square collapse into a single internal edge. You will have to set that the dofs of both sides are the same, similar to what is done in multipatch. This topic was already discussed in the mailing list. Regards, Rafa > Hi all, > > I'm trying to build Matlab IGA own codes, just for having full knowledge > and control of the relative routines. Obviously I use GeoPDEs as a > reference for benchmark and results. > > In particular, I have a 3D hollow cylinder, and I'm trying to compute > its modal analysis. I obtained strange results so i tried to compare my > stiffness matrix with the one calculated by GeoPDEs. > > The layout of the matrices appears very different, and this could be > related to the order of the DoF are listed. > > In my code, they are: >  u_1x >  u_1y >  u_1z >  u_2x >  u_2y >  u_2z >  ... > > Which is the order of the DoF in the e lasticity package of GeoPDEs? > > Thank you very much for the help! > > Kindest regards, > Marco > >  > Marco Brino > Politecnico di Torino  DIGEP > Corso Duca degli Abruzzi, 24 > I10129 Torino, Italy > +39 011 090 7205 > +39 393 554 4537 > marco.brino@... > > >  > Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, > MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current > with LearnDevNow  3,200 stepbystep video tutorials by Microsoft > MVPs and experts. SALE $99.99 this month only  learn more at: > http://p.sf.net/sfu/learnmore_122412 > _______________________________________________ > Geopdesusers mailing list > Geopdesusers@... > https://lists.sourceforge.net/lists/listinfo/geopdesusers > 
From: Marco Brino <marco.brino@po...>  20130114 09:41:18

Hi all, I'm trying to build Matlab IGA own codes, just for having full knowledge and control of the relative routines. Obviously I use GeoPDEs as a reference for benchmark and results. In particular, I have a 3D hollow cylinder, and I'm trying to compute its modal analysis. I obtained strange results so i tried to compare my stiffness matrix with the one calculated by GeoPDEs. The layout of the matrices appears very different, and this could be related to the order of the DoF are listed. In my code, they are:  u_1x  u_1y  u_1z  u_2x  u_2y  u_2z  ... Which is the order of the DoF in the e lasticity package of GeoPDEs? Thank you very much for the help! Kindest regards, Marco  Marco Brino Politecnico di Torino  DIGEP Corso Duca degli Abruzzi, 24 I10129 Torino, Italy +39 011 090 7205 +39 393 554 4537 marco.brino@... 