fix build and add test for newtons_method

src/lib.rs

@@ -31,6 +31,7 @@ pub use crate::{
 		// decimal_round,
 		hashed_storage_create,
 		hashed_storage_read,
+		newtons_method,
 		option_vec_printer,
 		step_helper,
 		EguiHelper,

src/misc.rs

@@ -247,7 +247,7 @@ pub fn newtons_method_helper(
 /// `f` is f(x)
 /// `f_1` is f'(x) aka the derivative of f(x)
 /// The function returns an `Option<f64>` of the x value at which a root occurs
-fn newtons_method(
+pub fn newtons_method(
 	f: &dyn Fn(f64) -> f64, f_1: &dyn Fn(f64) -> f64, start_x: &f64, range: &std::ops::Range<f64>,
 	threshold: &f64,
 ) -> Option<f64> {