This directory contains some tough (or not so tough) tests based mainly on
some real data (except Examples 1 and 3), on which `nn' has initially failed.
Example 1 is added for a comparison with the `csa' package in the case of
uniformly distributed data.

Example 1: uniformly distributed random measurements of Franke test fuction.

Example 2: bathymetry from sonar.

Example 3: degenerate case: both interpolation points and data points lie in
           the nodes of a rectangular grid.

Example 4: topographic data from a satellite altimeter.

Example 5: topographic data from digitised contours.

Example 6: topographic data from digitised contours.
