Implemented 2d tapered bar problem, for comparison of 2d and 1d results

gpexamples/gp2dtapered/meshes/4-node/bar_coarse.geo

+// This variable is a characteristic length and it controles the mesh size around a Point.
+// It is possible to specify more than one variable for this purpose.
+cl = 0.25;
+
+// These variables control the dimensions
+H = 0.25;
+L = 1.;
+
+// Points contains the x, y and z coordinate and the characteristic length of the Point.
+Point(1) = {0,0,0,cl};
+Point(2) = {L,0,0,cl};
+Point(3) = {L,H,0,cl};
+Point(4) = {0,H,0,cl};
+
+// A Line is basically a connection between two Points. A good practice is to connect the
+// Points in a counter-clockwise fashion.
+Line(1) = {1,2};
+Line(2) = {2,3};
+Line(3) = {3,4};
+Line(4) = {4,1};
+
+// A Line Loop is the connection of Lines that defines an area. Again it is good practice
+// to do this in a counter-clockwise fashion.
+Line Loop(1) = {1,2,3,4};
+
+// From the Line Loop it is now possible to create a surface, in this case a Plane Surface.
+Plane Surface(1) = {1};
+
+// From the Plane Surface a Physical Surface is generated, this makes is possible to only
+// save elements which are defined on the area specified by the Line Loop.
+Physical Surface(1) = {1};
+
+// To create a structured mesh, we need to definte TransFinite Curves+
+Transfinite Curve {1,3} = 5 Using Progression 1;
+Transfinite Curve {2,4} = 2 Using Progression 1;
+
+// Now, create a Transfinite Surface, and recombine to convert the triangles to quads
+Transfinite Surface {1};
+Recombine Surface {1};