This library contains routines for fitting (least squares) a multidimensional cubic spline to arbitrarily located data. It also contains routines for evaluating this spline (or its partial derivatives) at any point. This is a modernization of the double precision SPLPAK files from NCL.

A fpm.toml file is provided for compiling splpak with the Fortran Package Manager. For example, to build:

fpm build --profile release

By default, the library is built with double precision (real64) real values. Explicitly specifying the real kind can be done using the following processor flags:

For example, to build a single precision version of the library, use:

fpm build --profile release --flag "-DREAL32"

To run the unit tests:

fpm test --profile release

To use splpak within your fpm project, add the following to your fpm.toml file:

[dependencies]
splpak = { git="https://github.com/jacobwilliams/splpak.git" }

or, to use a specific version:

[dependencies]
splpak = { git="https://github.com/jacobwilliams/splpak.git", tag = "2.0.0"  }

The latest API documentation can be found here. This was generated from the source code using FORD (i.e. by running ford ford.md).

• The NCAR Command Language (specificially, the csagrid directory)
• bspline - Cubic B-Spline implementation in C++ templates. Also has a copy of splpak.f
• Ngmath Library Overview
• bspline-fortran Multidimensional B-Spline Interpolation of Data on a Regular Grid
• regridpack Linear or cubic interpolation for 1D-4D grids
• finterp 1D-6D linear or nearest-neighbor interpolation