add reference to wikipedia

interpn/src/multilinear/rectilinear.rs

@@ -49,6 +49,9 @@
 //! // Do interpolation
 //! rectilinear::interpn(grids, &z, &obs, &mut out);
 //! ```
+//! 
+//! References
+//! * https://en.wikipedia.org/wiki/Bilinear_interpolation#Weighted_mean
 use num_traits::Float;
 
 /// An arbitrary-dimensional multilinear interpolator / extrapolator on a rectilinear grid.

interpn/src/multilinear/regular.rs

@@ -52,6 +52,9 @@
 //! // Do interpolation
 //! regular::interpn(&dims, &starts, &steps, &z, &obs, &mut out);
 //! ```
+//!
+//! References
+//! * https://en.wikipedia.org/wiki/Bilinear_interpolation#Weighted_mean
 use num_traits::{Float, NumCast};
 
 /// An arbitrary-dimensional multilinear interpolator / extrapolator on a regular grid.
@@ -91,8 +94,7 @@ pub struct RegularGridInterpolator<'a, T: Float, const MAXDIMS: usize> {
     vals: &'a [T],
 }
 
-impl<'a, T: Float, const MAXDIMS: usize> RegularGridInterpolator<'a, T, MAXDIMS>
-{
+impl<'a, T: Float, const MAXDIMS: usize> RegularGridInterpolator<'a, T, MAXDIMS> {
     /// Build a new interpolator, using O(MAXDIMS) calculations and storage.
     ///
     /// This method does not handle degenerate dimensions with only a single
@@ -449,7 +451,7 @@ impl<'a, T: Float, const MAXDIMS: usize> RegularGridInterpolator<'a, T, MAXDIMS>
 /// number for the MAXDIMS parameter, as this will slightly reduce compute and storage overhead,
 /// and the underlying method can be extended to more than this function's limit of 8 dimensions.
 /// The limit of 8 dimensions was chosen for no more specific reason than to reduce unit test times.
-/// 
+///
 /// While this method initializes the interpolator struct on every call, the overhead of doing this
 /// is minimal even when using it to evaluate one observation point at a time.
 #[inline(always)]
@@ -547,7 +549,7 @@ mod test {
     /// to traverse every combination of interpolating or extrapolating high or low on each dimension.
     /// Each test evaluates at 3^ndims locations, largely extrapolated in corner regions, so it
     /// rapidly becomes prohibitively slow after about ndims=9.
-    /// 
+    ///
     ///  Make every other dimension have a negative step size to make sure
     ///  that mixing negative and positive steps works as intended.
     #[test]