Refactored interpolation imports in three modules

The codebase has been refactored so that the 'find_index_at_left_boundary' function is directly imported in the 'natural_cubic.rs', 'catmull_rom.rs', and 'linear.rs' modules. This change simplifies function calls within these modules, making the code easier to read and understand.

crates/qlab-math/src/interpolation/linear.rs

@@ -1,5 +1,4 @@
-use crate::interpolation;
-use crate::interpolation::{Interpolator, Point2D};
+use crate::interpolation::{find_index_at_left_boundary, Interpolator, Point2D};
 use crate::value::Value;
 use num_traits::real::Real;
 use qlab_error::InterpolationError;
@@ -73,7 +72,7 @@ impl<V: Value> Interpolator<Linear<V>, V> for Linear<V> {
     ///
     /// * `InvalidInput` - Represents an error when the input is invalid or out-of-bounds.
     fn try_value(&self, x: V) -> Result<V, InterpolationError<V>> {
-        let pos = interpolation::find_index_at_left_boundary(&self.points, x)?;
+        let pos = find_index_at_left_boundary(&self.points, x)?;
 
         Ok(self.points[pos].y
             + (self.points[pos + 1].y - self.points[pos].y)

crates/qlab-math/src/interpolation/spline/catmull_rom.rs

@@ -1,6 +1,5 @@
-use crate::interpolation;
 use crate::interpolation::spline::Value;
-use crate::interpolation::{Interpolator, Point2D};
+use crate::interpolation::{find_index_at_left_boundary, Interpolator, Point2D};
 use nalgebra::{Matrix4, Vector4};
 use qlab_error::InterpolationError;
 use std::ops::Mul;
@@ -65,7 +64,7 @@ impl<V: Value> Interpolator<CatmullRom<V>, V> for CatmullRom<V> {
     /// * Will panic if `V` cannot cast the constant `6`.
     #[allow(clippy::too_many_lines)]
     fn try_value(&self, x: V) -> Result<V, InterpolationError<V>> {
-        let pos = interpolation::find_index_at_left_boundary(&self.points, x)?;
+        let pos = find_index_at_left_boundary(&self.points, x)?;
 
         let point = &self.points[pos];
         let next_point = &self.points[pos + 1];

crates/qlab-math/src/interpolation/spline/natural_cubic.rs

@@ -1,6 +1,5 @@
-use crate::interpolation;
 use crate::interpolation::spline::Value;
-use crate::interpolation::{Interpolator, Point2DWithSlope};
+use crate::interpolation::{find_index_at_left_boundary, Interpolator, Point2DWithSlope};
 use crate::linear_algebra::tridiagonal_matrix::TridiagonalMatrix;
 use qlab_error::InterpolationError;
 
@@ -106,7 +105,7 @@ impl<V: Value> Interpolator<NaturalCubic<V>, V> for NaturalCubic<V> {
     /// * Will panic if `V` cannot cast constants.
     ///
     fn try_value(&self, x: V) -> Result<V, InterpolationError<V>> {
-        let pos = interpolation::find_index_at_left_boundary(&self.points, x)?;
+        let pos = find_index_at_left_boundary(&self.points, x)?;
         let point = &self.points[pos];
         let next_point = &self.points[pos + 1];
         let h = next_point.coordinate.x - point.coordinate.x;