Galerkin FEM for elliptic PDEs
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VTKEdgeGsphere.cpp 5.7KB

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  1. /* This file is part of Lemma, a geophysical modelling and inversion API.
  2. * More information is available at http://lemmasoftware.org
  3. */
  4. /* This Source Code Form is subject to the terms of the Mozilla Public
  5. * License, v. 2.0. If a copy of the MPL was not distributed with this
  6. * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  7. */
  8. /**
  9. * @file
  10. * @date 08/07/2014 04:16:25 PM
  11. * @version $Id$
  12. * @author Trevor Irons (ti)
  13. * @email Trevor.Irons@xri-geo.com
  14. * @copyright Copyright (c) 2014, XRI Geophysics, LLC
  15. * @copyright Copyright (c) 2014, Trevor Irons
  16. */
  17. #include <vtkUnstructuredGrid.h>
  18. #include <vtkUnstructuredGridReader.h>
  19. #include <vtkUnstructuredGridWriter.h>
  20. #include <vtkGenericDataObjectReader.h>
  21. #include <vtkXMLUnstructuredGridReader.h>
  22. #include <vtkXMLUnstructuredGridWriter.h>
  23. #include <vtkDoubleArray.h>
  24. #include <vtkPointData.h>
  25. #include <cmath>
  26. #include <Eigen/Core>
  27. const double PI = 4.0*atan(1.0);
  28. int main(int argc, char**argv) {
  29. std::cout << "Mesh processing routine\n";
  30. if (argc<4) {
  31. std::cout << "usage:\n" << "./utVTKEdge inMesh.vtu <radius> <problemType> outG.vtu" << std::endl;
  32. exit(EXIT_SUCCESS);
  33. }
  34. vtkUnstructuredGrid* uGrid = vtkUnstructuredGrid::New();
  35. std::string fn = argv[1];
  36. if(fn.substr(fn.find_last_of(".") + 1) == "vtk") {
  37. vtkGenericDataObjectReader* Reader = vtkGenericDataObjectReader::New();
  38. Reader->SetFileName(argv[1]);
  39. Reader->Update();
  40. if(Reader->IsFileUnstructuredGrid()) {
  41. std::cout << "Found Unstructured grid legacy file" << std::endl;
  42. uGrid = Reader->GetUnstructuredGridOutput();
  43. } else {
  44. std::cerr << "Unknown legacy format";
  45. exit(EXIT_FAILURE);
  46. }
  47. } else {
  48. vtkXMLUnstructuredGridReader* Reader = vtkXMLUnstructuredGridReader::New();
  49. std::cout << "Reading" << argv[1] << std::endl;
  50. Reader->SetFileName(argv[1]);
  51. Reader->Update();
  52. uGrid = Reader->GetOutput();
  53. }
  54. int nc = uGrid->GetNumberOfCells() ;
  55. int nn = uGrid->GetNumberOfPoints() ;
  56. std::cout << "Processing grid with nodes=" << nn << "\t cells=" << nc << "\n";
  57. // Input magnet size TODO get from file or .geo file even?
  58. double R = atof(argv[2]); //.25; // radius of magnet
  59. double eps = 1e-4; // epsilon for on the point
  60. // Pol = double[3];
  61. // Declare new array for the data
  62. vtkDoubleArray* G = vtkDoubleArray::New();
  63. G->SetNumberOfComponents(1);
  64. G->SetNumberOfTuples(nn);
  65. G->SetName("G");
  66. vtkDoubleArray* phi = vtkDoubleArray::New();
  67. phi->SetNumberOfComponents(1);
  68. phi->SetNumberOfTuples(nn);
  69. phi->SetName("analytic_phi");
  70. // Loop over nodes, look at position, set with G if on boundary
  71. double point[3];
  72. Eigen::Vector3d M; M << 0,0,1;
  73. for (int in=0; in<nn; ++in) {
  74. uGrid->GetPoint(in, &point[0]);
  75. //std::cout << point[0] << "\t" <<point[1] << "\t" << point[2] << std::endl;
  76. double raddist = sqrt( point[0]*point[0] + point[1]*point[1] + point[2]*point[2] );
  77. //double rho = sqrt( point[1]*point[1] + point[2]*point[2] );
  78. // Calculate RHS
  79. if ( std::string(argv[3]) == "gravity") {
  80. if ( raddist < R + eps) {
  81. G->InsertTuple1( in, 1 );
  82. } else {
  83. G->InsertTuple1( in, 0 );
  84. }
  85. }
  86. else if ( std::string(argv[3]) == "magnet") {
  87. if ( raddist > R - eps && raddist < R + eps ) {
  88. // \rho = \nabla \cdot \mathbf{M}
  89. //
  90. if ( point[2] < -eps ) {
  91. G->InsertTuple1( in, 1 );
  92. } else if (point[2] > eps) {
  93. G->InsertTuple1( in, -1 );
  94. } else {
  95. G->InsertTuple1( in, 0 );
  96. }
  97. //
  98. // Above is inaccurate and unstable
  99. // Use divergence theorm --> \mahtbf{M} \cdot \hat{n}
  100. Eigen::Vector3d n;
  101. n << point[0],point[1],point[2];
  102. n.array() /= raddist;
  103. //double sigma = n.dot(M);
  104. G->InsertTuple1(in, n.dot(M) );
  105. } else {
  106. G->InsertTuple1( in, 0 );
  107. }
  108. }
  109. // Insert analytic phi part
  110. /* magnetics problem p. 198 Jackson */
  111. if (std::string(argv[3]) == "magnet") {
  112. if (raddist < R) {
  113. phi->InsertTuple1( in, (1./3.)*point[2] );
  114. } else {
  115. phi->InsertTuple1( in, 0);
  116. double costheta = point[2]/raddist ;
  117. //phi->InsertTuple1( in, -(1./3.)*(R*R*R) * ( costheta / (rho*rho) ) );
  118. phi->InsertTuple1( in, (1./3.) * (R*R*R) * (costheta / (raddist*raddist)) );
  119. }
  120. } else if (std::string(argv[3]) == "gravity") {
  121. double mass = 4./3. * PI * (R*R*R);
  122. if (raddist < R) {
  123. phi->InsertTuple1( in, mass * ( 3*(R*R) - raddist*raddist )/(2*(R*R*R)) ); // (1./3.)*point[2] );
  124. } else {
  125. //phi->InsertTuple1( in, 0);
  126. //double costheta = point[2]/raddist ;
  127. //phi->InsertTuple1( in, -(1./3.)*(R*R*R) * ( costheta / (rho*rho) ) );
  128. phi->InsertTuple1( in, mass/raddist );
  129. }
  130. }
  131. }
  132. // Add new data
  133. uGrid->GetPointData()->AddArray( phi );
  134. uGrid->GetPointData()->SetScalars( G );
  135. // Write out new file
  136. vtkXMLUnstructuredGridWriter* Writer = vtkXMLUnstructuredGridWriter::New();
  137. //Writer->SetInputConnection(Reader->GetOutputPort());
  138. Writer->SetInputData( uGrid );
  139. Writer->SetFileName( argv[4] );
  140. Writer->Write();
  141. //Reader->Delete();
  142. }