TOMS626
A Contour Plot Program for Triangular Meshes

TOMS626 is a FORTRAN77 library which implements ACM TOMS algorithm 626, for creating contour plots of scalar data associated with triangular meshes.

The text of many ACM TOMS algorithms is available online through ACM: http://www.acm.org/pubs/calgo or NETLIB: http://www.netlib.org/toms/index.html.

Languages:

TOMS626 is available in a FORTRAN77 version.

Related Data and Programs:

CONTOUR_SEQUENCE, a MATLAB program which reads a sequence of (X,Y,U(X,Y)) datasets, creates contour plots, and saves them as PNG files which can be combined into an animation (by Quicktime Pro, for instance). It expects that each input file contains the X and Y coordinates and the scalar data (this means the geometry can be time-dependent).

CONTOUR_SEQUENCE3, a MATLAB program which reads a sequence of (X,Y,U(X,Y)) datasets, creates contour plots, and saves them as PNG files which can be combined into an animation (by Quicktime Pro, for instance). It expects two separate node coordinate files, one for the X coordinates and one for the Y coordinates, and a separate file for the scalar quantity.

CONTOUR_SEQUENCE4, a MATLAB program which reads a sequence of (X,Y,U(X,Y)) datasets, creates contour plots, and saves them as PNG files which can be combined into an animation (by Quicktime Pro, for instance). It expects a separate node coordinate file of the XY coordinates, and a separate file for the scalar quantity.

DISLIN, a FORTRAN77 library which includes contouring software.

Reference:

1. Hiroshi Akima,
   Bivariate Interpolation and Smooth Surface Fitting,
   ACM Transactions on Mathematical Software,
   Volume 4, Number 2, June 1978, pages 148-159.
2. Hiroshi Akima,
   Algorithm 526: A Method of Bivariate Interpolation and Smooth Surface Fitting for Values Given at Irregularly Distributed Points,
   ACM Transactions on Mathematical Software,
   Volume 4, Number 2, June 1978, pages 160-164.
3. Albrecht Preusser,
   Algorithm 626: TRICP: A Contour Plot Program for Triangular Meshes,
   ACM Transactions on Mathematical Software,
   Volume 10, Number 4, December 1984, pages 473-475.
4. Hans Rudolf Schwarz,
   Methode der Finiten Elemente,
   Teubner Studienbuecher, 1980,
   ISBN: 3-519-02349-0.

Source Code:

• toms626.f, the source code.
• toms626.sh, commands to compile the source code.

• calcomp.f, some plotting routines needed for the examples.
• calcomp.sh, commands to compile the source code.

Examples and Tests:

PROBLEM1 demonstrates modes 0 (triangulation of the data is required) and 2 (use the same triangles but different Z values):

• toms626_prb1.f, a sample calling program.
• toms626_prb1.sh, commands to compile and run the sample program.
• toms626_prb1_output.txt, the output from a run of the sample program.
• toms626_prb1_001.png, a PNG image of plot #1.
• toms626_prb1_002.png, a PNG image of plot #2.

PROBLEM2 demonstrates modes 1 (triangulation is provided by user) and 3 (some partial derivatives are set):

• toms626_prb2.f, a sample calling program.
• toms626_prb2.sh, commands to compile and run the sample program.
• toms626_prb2_output.txt, the output from a run of the sample program.
• toms626_prb2_001.png, a PNG image of plot #1.
• toms626_prb2_002.png, a PNG image of plot #2.

List of Routines:

• IDCLDP finds several data points closest to a given point.
• IDPDRV estimates partial derivatives at the data points.
• IDTANG determines a triangulation of points in the plane.
• IDXCHG determines whether to reform two triangles by swapping the diagonal.
• TIMESTAMP prints out the current YMDHMS date as a timestamp.
• TRICP is the user interface for the triangle contour plotting program.
• TRICPF evaluates the interpolating function or its derivatives.
• TRICPZ seeks a zero of a function between two points.
• TRP001 computes polynomial coefficients along sides.
• TRP002 computs polynomial coefficients inside the triangle.
• TRP00 calls TRP001 and TRP002 for the computation of polynomial coefficients.

You can go up one level to the FORTRAN77 source codes.