Interpolation of Scattered Data in 3D

TOMS661 is a FORTRAN77 library which interpolates scattered 3D data, also known as "qshep3d", by Robert Renka.

TOMS661 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.

TOMS661 is ACM Transactions on Mathematical Software Algorithm number 661. The original text of any ACM TOMS algorithm is available through ACM: or NETLIB:


TOMS661 is available in a FORTRAN77 version and a FORTRAN90 version.

Related Data and Programs:

RBF_INTERP_ND, a FORTRAN77 library which defines and evaluates radial basis interpolants to multidimensional data.

TOMS660, a FORTRAN77 library which takes scattered 2D data and produces an interpolating function F(X,Y).


Robert Renka


  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:

Examples and Tests:

List of Routines:

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

Last revised on 27 January 2012.