diff --git a/doc/rst/source/contour.rst b/doc/rst/source/contour.rst index 84fd362fb7d..774fca59a5d 100644 --- a/doc/rst/source/contour.rst +++ b/doc/rst/source/contour.rst @@ -56,9 +56,9 @@ Description Reads an ASCII [or binary] *table* and produces a raw contour plot by triangulation. By default, the optimal Delaunay triangulation is performed (using either Shewchuk's [1996] or Watson's -[1982] method as selected during GMT installation; run the module with argument -**-** to see which method is selected), but the user may optionally -provide a second file with network information, such as a triangular +[1982] method as selected during GMT installation; run +**gmt get GMT_TRIANGULATE** to see which method is selected), but the user may +optionally provide a second file with network information, such as a triangular mesh used for finite element modeling. In addition to contours, the area between contours may be painted according to the CPT. Alternatively, the *x, y, z* positions of the contour lines may be saved to diff --git a/doc/rst/source/gmt.conf.rst b/doc/rst/source/gmt.conf.rst index 1baea93aadf..5d4fa30659d 100644 --- a/doc/rst/source/gmt.conf.rst +++ b/doc/rst/source/gmt.conf.rst @@ -507,7 +507,7 @@ GMT Miscellaneous Parameters Determines if we use the **Watson** or **Shewchuk** algorithm (if configured during installation) for triangulation. Note that Shewchuk is required for operations involving Voronoi - constructions [default is **Watson**]. + constructions [default is **Shewchuk**]. **GMT_VERBOSE** (**-V**) Determines the level of verbosity used by GMT diff --git a/doc/rst/source/triangulate.rst b/doc/rst/source/triangulate.rst index 77bcfe5d4fe..002e6f3c1cf 100644 --- a/doc/rst/source/triangulate.rst +++ b/doc/rst/source/triangulate.rst @@ -57,8 +57,8 @@ input file. As an option, you may choose to create a multiple segment file that can be piped through :doc:`plot` to draw the triangulation network. If **-G** **-I** are set a grid will be calculated based on the surface defined by the planar triangles. The actual algorithm used in -the triangulations is either that of Watson [1982] [Default] or Shewchuk -[1996] (if installed; type **triangulate -** to see which method is +the triangulations is either that of Watson [1982] or Shewchuk [1996] [Default] +(if installed; type **gmt get GMT_TRIANGULATE** to see which method is selected). This choice is made during the GMT installation. Furthermore, if the Shewchuk algorithm is installed then you can also perform the calculation of Voronoi polygons and optionally grid your data via the diff --git a/src/TRIANGLE.HOWTO b/src/TRIANGLE.HOWTO index 9abcd2d7275..f3f2efbc2b2 100644 --- a/src/TRIANGLE.HOWTO +++ b/src/TRIANGLE.HOWTO @@ -1,9 +1,9 @@ GMT contains two programs (triangulate and pscontour) that directly or indirectly will do a Delaunay optimal triangulation -of arbitrarily spaced (x,y,z) data. By default, GMT uses +of arbitrarily spaced (x,y,z) data. In the early days, GMT used a public domain (published) algorithm by Dave Watson [1982] to -to this. Now, a new and much faster algorithm has been released +to this. The default now though, is a new and much faster algorithm by Jonathan Shewchuk [1996]. Because Shewchuk holds the copyright (i.e., it is not in the public domain nor distributed under the GNU Public License or the equivalent) you are advised to read it (see @@ -15,12 +15,12 @@ If you later need to change the behavior w.r.t. triangulation, follow these guidelines: In makegmt.macro there are two parameters that can be defined: -TRIANGLE_D and TRIANGLE_O. By default they are commented out. +TRIANGLE_D and TRIANGLE_O. By default these lines are commented out. To use Shewchuk's [1996] routine, remove the # from the beginning of the lines and then 'make clean' and 'make install'. -To revert to the default GMT usage of Watson's [1982] algorithm, +To revert to using Watson's [1982] algorithm, simply place a # in the first column at these two lines. -Then, say 'make clean' and 'make install' again. +Then, run 'make clean' and 'make install' again. Paul Wessel, 16-AUG-1999