Struct BilinearInterp 

pub struct BilinearInterp<T, const NX: usize, const NY: usize> { /* private fields */ }

Bilinear interpolant on a rectangular grid (fixed-size, stack-allocated).

Interpolates z = f(x, y) on an NX × NY grid by linearly interpolating first in x, then in y. Out-of-bounds queries extrapolate using the nearest boundary cell.

Internal storage is column-major: zs[ix][iy] holds the value at (xs[ix], ys[iy]). The constructor accepts row-major input (each inner array is a row at fixed y) and transposes internally, matching the Matrix::new() convention.

Example

use numeris::interp::BilinearInterp;

// 3×2 grid: z = x + y
let xs = [0.0_f64, 1.0, 2.0];
let ys = [0.0, 1.0];
// Row-major input: zs_input[iy][ix]
let zs = [
    [0.0, 1.0, 2.0],  // y = 0
    [1.0, 2.0, 3.0],  // y = 1
];
let interp = BilinearInterp::new(xs, ys, zs).unwrap();
assert!((interp.eval(0.5, 0.5) - 1.0).abs() < 1e-14);

Implementations

impl<T: FloatScalar, const NX: usize, const NY: usize> BilinearInterp<T, NX, NY>

pub fn new( xs: [T; NX], ys: [T; NY], zs_rows: [[T; NX]; NY], ) -> Result<Self, InterpError>

Construct a bilinear interpolant from sorted grid knots.

zs_rows[j][i] is the value at (xs[i], ys[j]) — row-major input. Each inner array is a “row” of z-values at a fixed y-coordinate. Internally transposed to column-major storage.

Returns InterpError::TooFewPoints if NX < 2 or NY < 2, InterpError::NotSorted if xs or ys is not strictly increasing.

pub fn eval(&self, x: T, y: T) -> T

Evaluate the interpolant at (x, y).

pub fn xs(&self) -> &[T; NX]

The grid x-knots.

pub fn ys(&self) -> &[T; NY]

The grid y-knots.

Trait Implementations

impl<T: Clone, const NX: usize, const NY: usize> Clone for BilinearInterp<T, NX, NY>

fn clone(&self) -> BilinearInterp<T, NX, NY>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Debug, const NX: usize, const NY: usize> Debug for BilinearInterp<T, NX, NY>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.