ninterp

The ninterp crate provides multivariate interpolation over rectilinear grids of any dimensionality. A variety of interpolation strategies are implemented, however more are likely to be added. Extrapolation beyond the range of the supplied coordinates is supported for 1-D linear interpolators, using the slope of the nearby points.

There are hard-coded interpolators for lower dimensionalities (up to N = 3) for better runtime performance.

cargo add ninterp

Feature Flags

• serde: support for serde

Getting Started

A prelude module has been defined: use ninterp::prelude::*;. This exposes the types necessary for usage: Interpolator, Strategy, Extrapolate, and the trait InterpMethods.

All interpolation is handled through instances of the Interpolator enum.

Interpolation is executed by calling Interpolator::interpolate. The length of the supplied point slice must be equal to the interpolator dimensionality. The interpolator dimensionality can be retrieved by calling Interpolator::ndim.

Note

For interpolators of dimensionality N ≥ 1:

• Instantiation is done via the Interpolator enum's new_* methods (new_1d, new_2d, new_3d, new_nd). These methods run a validation step that catches any potential errors early, preventing runtime panics.
  • To set or get field values, use the corresponding named methods (x, set_x, etc.).
• An interpolation Strategy (e.g. linear, left-nearest, etc.) must be specified. Not all interpolation strategies are implemented for every dimensionality. Strategy::Linear is implemented for all dimensionalities.
• An Extrapolate setting must be specified. This controls what happens when a point is beyond the range of supplied coordinates. If you are unsure which variant to choose, Extrapolate::Error is likely what you want.

For 0-D (constant-value) interpolators, instantiate directly, e.g. Interpolator::Interp0D(0.5)

Examples

• Interpolator::Interp0D
• Interpolator::new_1d
• Interpolator::new_2d
• Interpolator::new_3d
• Interpolator::new_nd