The Csagrid package contains functionally equivalent interfaces for Fortran, C, and NCL.

Each interface is divided into entries for one-dimensional, two-dimensional, and three-dimensional data. For each of the three dimensionalities, there are simplified entries and expanded entries. The expanded entries are provided in the cases you want to find derivatives, weight the input data values, or extrapolate into data sparse regions. For the two-dimensional and three-dimensional entries, you also have the option of choosing output on a user-specified grid, or at a user-specified set of points.

Each of the entries in the Csagrid package has an argument for specifying the number of knots to use, hence it is necessary for you to understand that concept. See the section on knot selection in the module on the basic capabilities.

The entry points, as outlined above, are summarized in the Csagrid procedures module. To proceed, go to that summary table and click on your desired entry point for details.