TOMS526
Bivariate interpolation of scattered data

TOMS526 is a library of FORTRAN77 routines, using double precision arithmetic, for the interpolation of scattered bivariate data.

TOMS526 accepts a set of (X,Y) data points scattered in 2D, with associated Z data values, and is able to construct a smooth interpolation function Z(X,Y), which agrees with the given data, and can be evaluated at other points in the plane.

TOMS526 is ACM TOMS Algorithm 526.

The original, true, correct version of ACM TOMS 526 is available in the TOMS subdirectory of the NETLIB web site.

Related Data and Packages:

BIVAR is a FORTRAN90 libary of routines which is a version of TOMS526.

QSHEP2D is a FORTRAN90 library of routines which interpolate scattered data in 2D.

QSHEP3D is a FORTRAN90 library of routines which interpolate scattered data in 3D.

Author:

Hiroshi Akima

Reference:

1. 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.
2. Hiroshi Akima,
   On Estimating Partial Derivatives for Bivariate Interpolation of Scattered Data,
   Rocky Mountain Journal of Mathematics,
   Volume 14, Number 1, Winter 1984, pages 41-51.

Source Code:

• toms526.f, the source code.
• toms526.csh, commands to compile the source code.

Examples and Tests:

• toms526_prb.f, a sample problem.
• toms526_prb.csh, commands to compile, link and run the sample problem.
• toms526_prb.out, sample problem output.

List of Routines:

• IDBVIP performs bivariate interpolation of irregular X, Y data.
• IDGRID organizes grid points for surface fitting.
• IDLCTN finds the triangle that contains a point.
• IDPDRV estimates first and second partial derivatives at data points.
• IDPTIP performs interpolation, determining a value of Z given X and Y.
• IDSFFT performs smooth surface fitting when the projections of the
• IDTANG performs triangulation.
• IDXCHG determines whether two triangles should be exchanged.

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