Adding toroid example

examples/magnet/toroid.geo

@@ -0,0 +1,105 @@
+/* This file is part of Lemma, a geophysical modelling and inversion API.
+ * More information is available at http://lemmasoftware.org
+ */
+
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+/**
+ * @file
+ * @date      02/04/2016 02:58:54 PM
+ * @version   $Id$
+ * @author    Trevor Irons (ti)
+ * @email     tirons@egi.utah.edu
+ * @copyright Copyright (c) 2016, University of Utah
+ * @copyright Copyright (c) 2016, Lemma Software, LLC
+ */
+
+radius = 3.25;   // Radius of the damn thing
+blc = radius/2;  //  0.25;   // Target element size
+Box = 3*radius;  // The down side of potential
+lc = radius/2;        // toroid characteristic length
+
+
+tpp = newp;
+ts = 1;         // height of toroid
+tx = radius;  // radial width of toroid, measured in centre of ring
+tl = 0;         // centre of rotation
+
+Point(tpp  ) = {    tx,    0, 0,  lc};
+Point(tpp+1) = { ts+tx,    0, 0,  lc};
+Point(tpp+2) = {    tx,   ts, 0,  lc};
+Point(tpp+3) = {    tx,  -ts, 0,  lc};
+Point(tpp+4) = {-ts+tx,    0, 0,  lc};
+
+cc = newc;
+Circle(cc  ) = {tpp+1, tpp, tpp+2};
+Circle(cc+1) = {tpp+2, tpp, tpp+4};
+Circle(cc+2) = {tpp+4, tpp, tpp+3};
+Circle(cc+3) = {tpp+3, tpp, tpp+1};
+
+ll = newll;
+Line Loop(ll) = {cc, cc+1, cc+2, cc+3};
+
+ps = news;
+pio2=Pi/2;
+Plane Surface(ps) = {ll};
+tv1[] = Extrude {{0, 1, 0},{-tl,0,0}, 2*Pi/3} { Surface{ps}; };
+tv2[] = Extrude {{0, 1, 0},{-tl,0,0}, 2*Pi/3} { Surface{28}; };
+tv3[] = Extrude {{0, 1, 0},{-tl,0,0}, 2*Pi/3} { Surface{50}; };
+//t1[] = Rotate {{0,0,1},{0,0,0},pio2  } {Duplicata{Surface{ps};}};
+//Extrude Surface {ps, {0,1,0}, {-tl,0,0}, 2*Pi/3} { Recombine ;};
+//Extrude Surface {28, {0,1,0}, {-tl,0,0}, 2*Pi/3}; //{Layers{10,73,1};};
+//Extrude Surface {50, {0,1,0}, {-tl,0,0}, 2*Pi/3}; //{Layers{10,73,1};};
+
+/* Make a list of a ring (annulus) of surfaces around the hole */
+allParts[] = {tv1[0], tv2[0], tv3[0]};
+
+/* Make surfaces to be meshed by transfinite algorithm */
+//Transfinite Surface {allParts[]};
+
+/* The "Recombine Surface" command is issued in order to
+ * crate quadrilateral elements.
+ */
+//Recombine Surface {allParts[]};
+
+// Extrude Surface {12, {0,0,1}, {0,0,0}, 2*Pi/3} {
+//   Recombine ; Layers { 6, 54, 1 } ;
+// } ;
+
+// Total Solution Space
+X0 = -Box;
+X1 =  Box;
+Y0 = -Box;
+Y1 =  Box;
+Z0 = -Box;
+Z1 =  Box;
+/////////////////////////////////////
+// Large Bounding box
+pp = newp;
+Point(pp)    = {X0, Y0, Z0, blc};
+Point(pp+1)  = {X1, Y0, Z0, blc};
+Point(pp+2)  = {X1, Y1, Z0, blc};
+Point(pp+3)  = {X0, Y1, Z0, blc};
+//
+lv = newl;
+Line(lv) = {pp,pp+1};
+Line(lv+1) = {pp+1,pp+2};
+Line(lv+2) = {pp+2,pp+3};
+Line(lv+3) = {pp+3,pp};
+Line Loop(lv+4) = {lv, lv+1, lv+2, lv+3};
+//
+// Hard coded doom
+bs = news;
+Plane Surface(bs) = {lv+4};
+//
+//v = newv;
+v[] = Extrude {0, 0, Z1-Z0} { Surface{bs}; };
+
+/* This is GOOD */
+Surface{ allParts } In Volume{v[1]};
+//Surface{t1[0]} In Volume{v[1]};
+//Surface{t2[0]} In Volume{v[1]};
+//Surface{t3[0]} In Volume{v[1]};