QSHEP3D
Interpolation of Scattered Data in 3D

QSHEP3D is a FORTRAN90 library which interpolates scattered 3D data.

QSHEP3D takes a set of data values WDAT(XDAT,YDAT,ZDAT), where the points (XDAT,YDAT,ZDAT) are "scattered" in 3D, and constructs an interpolating function W(X,Y,Z) which matches the given data and extends smoothly through 3D space.

QSHEP3D is primarily a FORTRAN90 "translation" of a FORTRAN77 program which was written by Robert Renka and published in the ACM Transactions on Mathematical Software.

QSHEP3D is ACM Transactions on Mathematical Software Algorithm number 661. The original text of any ACM TOMS algorithm is available through ACM: http://www.acm.org/pubs/calgo or NETLIB: http://www.netlib.org/toms/index.html

Related Data and Programs:

BIVAR is a FORTRAN90 library of routines which takes scattered 2D data and produces an interpolating function F(X,Y).

QSHEP2D is a FORTRAN90 library of routines which takes scattered 2D data and produces an interpolating function F(X,Y).

Author:

Robert Renka

Reference:

1. Robert Renka,
   Algorithm 661: QSHEP3D, Quadratic Shepard method for trivariate interpolation of scattered data,
   ACM Transactions on Mathematical Software,
   Volume 14, 1988, pages 151-152.

Source Code:

• qshep3d.f90, the source code.
• qshep3d.csh, commands to compile the source code.

Examples and Tests:

• qshep3d_prb.f90, a sample problem.
• qshep3d_prb.csh, commands to compile, load and run the sample problem.
• qshep3d_prb_output.txt, the output file.

List of Routines:

• QSHEP3 defines a smooth trivariate interpolant of scattered 3D data.
• QS3VAL evaluates the interpolant function Q(X,Y,Z) created by QSHEP3.
• QS3GRD computes the value and gradient of the interpolant function.
• GETNP3 finds the closest node to a given point.
• GIVENS constructs a Givens plane rotation.
• ROTATE applies a Givens rotation to two vectors.
• SETUP3 sets up the weighted least-squares fit of the data.
• STORE3 sets up a data structure for N scattered nodes in 3D.

You can go up one level to the FORTRAN90 source codes.