small MSH4.1 example

doc/texinfo/gmsh.texi

@@ -3915,6 +3915,48 @@ file format (@pxref{MSH file format version 2}). These sections will be
 reworked in a future minor revision of the version 4 format
 (e.g. version 4.1 or 4.2).
 
+Below is a small example (a mesh consisting of two quadrangles with an
+associated nodal scalar dataset; the comments are not part of the actual
+file!):
+
+@smallexample
+$MeshFormat
+4.1 0 8          @emph{MSH4.1, ASCII}
+$EndMeshFormat
+$Nodes
+1 6 1 6          @emph{1 entity, 6 nodes, min/max node tags: 1 and 6}
+2 1 0 6          @emph{surface 1, no parametric coordinates, 6 nodes}
+1 0. 0. 0.       @emph{  node #1: coordinates (0., 0., 0.)}
+2 1. 0. 0.       @emph{  node #2: coordinates (1., 0., 0.)}
+3 1. 1. 0.       @emph{  etc.}
+4 0. 1. 0.
+5 2. 0. 0.
+6 2. 1. 0.
+$EndNodes
+$Elements
+1 2 1 2          @emph{1 entity, 2 elements, min/max element tags: 1 and 2}
+2 1 3 2          @emph{surface 1, element type 3 (4-node quad), 2 elements}
+1 1 2 3 4        @emph{  quad #1: nodes 1 2 3 4}
+2 2 5 6 3        @emph{  quad #2: nodes 2 5 6 3}
+$EndElements
+$NodeData
+1                @emph{one string tag:}
+"A scalar view"  @emph{  the name of the view ("A scalar view")}
+1                @emph{one real tag:}
+0.0              @emph{  the time value (0.0)}
+3                @emph{three integer tags:}
+0                @emph{  the time step (0; time steps always start at 0)}
+1                @emph{  1-component (scalar) field}
+6                @emph{  six associated nodal values}
+1 0.0            @emph{value associated with node #1 (0.0)}
+2 0.1            @emph{value associated with node #2 (0.1)}
+3 0.2            @emph{etc.}
+4 0.0
+5 0.2
+6 0.4
+$EndNodeData
+@end smallexample
+
 @c -------------------------------------------------------------------------
 @c Node ordering
 @c -------------------------------------------------------------------------