diff --git a/src/egui_app.rs b/src/egui_app.rs
index 1cfcf7a..dd261d3 100644
--- a/src/egui_app.rs
+++ b/src/egui_app.rs
@@ -1,5 +1,5 @@
 use crate::function::{FunctionEntry, Riemann, DEFAULT_FUNCTION_ENTRY};
-use crate::misc::{option_vec_printer, JsonFileOutput, SerdeValueHelper};
+use crate::misc::{dyn_mut_iter, option_vec_printer, JsonFileOutput, SerdeValueHelper};
 use crate::parsing::{process_func_str, test_func};
 
 use crate::consts::*;
@@ -15,6 +15,9 @@ use instant::Duration;
 use shadow_rs::shadow;
 use std::{collections::BTreeMap, io::Read, ops::BitXorAssign, str};
 
+#[cfg(not(target_arch = "wasm32"))]
+use rayon::iter::{IndexedParallelIterator, ParallelIterator};
+
 shadow!(build);
 
 // Constant string that has a string containing information about the build.
@@ -688,23 +691,25 @@ impl epi::App for MathApp {
 					let minx_bounds: f64 = bounds.min()[0];
 					let maxx_bounds: f64 = bounds.max()[0];
 
-					area_list = self
-						.functions
-						.iter_mut()
+					dyn_mut_iter(&mut self.functions)
+						// .iter_mut()
 						.enumerate()
-						.map(|(i, function)| {
-							if self.func_strs[i].is_empty() {
-								return None;
-							}
-
-							function.display(
-								plot_ui,
+						.filter(|(i, _)| !self.func_strs[*i].is_empty())
+						.for_each(|(_, function)| {
+							function.calculate(
 								minx_bounds,
 								maxx_bounds,
 								width_changed,
 								settings_copy,
 							)
-						})
+						});
+
+					area_list = self
+						.functions
+						.iter()
+						.enumerate()
+						.filter(|(i, _)| !self.func_strs[*i].is_empty())
+						.map(|(_, function)| function.display(plot_ui, settings_copy))
 						.collect();
 				});
 		});
diff --git a/src/function.rs b/src/function.rs
index 1d5ec83..84b2f38 100644
--- a/src/function.rs
+++ b/src/function.rs
@@ -288,11 +288,8 @@ impl FunctionEntry {
 	}
 
 	/// Calculates and displays the function on PlotUI `plot_ui`
-	pub fn display(
-		&mut self, plot_ui: &mut PlotUi, min_x: f64, max_x: f64, width_changed: bool,
-		settings: AppSettings,
-	) -> Option<f64> {
-		self.calculate(min_x, max_x, width_changed, settings);
+	pub fn display(&self, plot_ui: &mut PlotUi, settings: AppSettings) -> Option<f64> {
+		// self.calculate(min_x, max_x, width_changed, settings);
 
 		let func_str = self.get_func_str();
 		let derivative_str = self.function.get_derivative_str();
diff --git a/src/misc.rs b/src/misc.rs
index 4618d06..04c5e93 100644
--- a/src/misc.rs
+++ b/src/misc.rs
@@ -6,16 +6,37 @@ use serde_json::Value as JsonValue;
 use rayon::prelude::*;
 
 #[cfg(target_arch = "wasm32")]
-pub fn dyn_iter<'a, T>(input: &'a Vec<T>) -> impl Iterator<Item = &'a T> { input.iter() }
+pub fn dyn_iter<'a, T>(input: &'a Vec<T>) -> impl Iterator<Item = &'a T>
+where
+	&'a [T]: IntoIterator,
+{
+	input.iter()
+}
 
 #[cfg(not(target_arch = "wasm32"))]
-pub fn dyn_iter<'a, T>(input: &'a Vec<T>) -> <&'a [T] as IntoParallelIterator>::Iter
+pub fn dyn_iter<'a, I>(input: &'a I) -> <&'a I as IntoParallelIterator>::Iter
 where
-	&'a [T]: IntoParallelIterator,
+	&'a I: IntoParallelIterator,
 {
 	input.par_iter()
 }
 
+#[cfg(target_arch = "wasm32")]
+pub fn dyn_mut_iter<'a, T>(input: &'a mut Vec<T>) -> impl Iterator<Item = &'a mut T>
+where
+	&'a mut [T]: IntoIterator,
+{
+	input.iter_mut()
+}
+
+#[cfg(not(target_arch = "wasm32"))]
+pub fn dyn_mut_iter<'a, I>(input: &'a mut I) -> <&'a mut I as IntoParallelIterator>::Iter
+where
+	&'a mut I: IntoParallelIterator,
+{
+	input.par_iter_mut()
+}
+
 pub trait VecValueToTuple {
 	fn to_tuple(&self) -> Vec<(f64, f64)>;
 }