diff --git a/src/func_plot.rs b/src/func_plot.rs
index 94457f8..67cffa0 100644
--- a/src/func_plot.rs
+++ b/src/func_plot.rs
@@ -1,18 +1,27 @@
 use crate::DrawResult;
+use meval::Expr;
 use plotters::prelude::*;
 use plotters_canvas::CanvasBackend;
 use web_sys::HtmlCanvasElement;
-use meval::Expr;
 
 /// Draw power function f(x) = x^power.
-pub fn draw(element: HtmlCanvasElement, func_str: &str, min_x: f32, max_x: f32, min_y: f32, max_y: f32, num_interval: usize, resolution: i32) -> DrawResult<(impl Fn((i32, i32))-> Option<(f32, f32)>, f32)> {
+pub fn draw(
+    element: HtmlCanvasElement,
+    func_str: &str,
+    min_x: f32,
+    max_x: f32,
+    min_y: f32,
+    max_y: f32,
+    num_interval: usize,
+    resolution: i32,
+) -> DrawResult<(impl Fn((i32, i32)) -> Option<(f32, f32)>, f32)> {
     let expr: Expr = func_str.parse().unwrap();
     let func = expr.bind("x").unwrap();
 
-    let absrange = (max_x-min_x).abs();
-    let step = absrange/(num_interval as f32);
+    let absrange = (max_x - min_x).abs();
+    let step = absrange / (num_interval as f32);
     let backend = CanvasBackend::with_canvas_object(element).unwrap();
-    
+
     let root = backend.into_drawing_area();
     let font: FontDesc = ("sans-serif", 20.0).into();
 
@@ -24,20 +33,24 @@ pub fn draw(element: HtmlCanvasElement, func_str: &str, min_x: f32, max_x: f32,
         .x_label_area_size(30 as f32)
         .y_label_area_size(30 as f32)
         .build_cartesian_2d(min_x..max_x, min_y..max_y)?;
-    
+
     chart.configure_mesh().x_labels(3).y_labels(3).draw()?;
 
     let data = (1..=resolution)
-        .map(|x| (((x as f32/resolution as f32))*(&absrange))+&min_x)
+        .map(|x| ((x as f32 / resolution as f32) * (&absrange)) + &min_x)
         .map(|x| (x, func(x as f64) as f32))
-        .filter(|(_,y)| &min_y <= y && y <= &max_y);
+        .filter(|(_, y)| &min_y <= y && y <= &max_y);
 
     chart.draw_series(LineSeries::new(data, &RED))?;
 
     let (data2, area) = integral_rectangles(min_x, step, num_interval, &func); // Get rectangle coordinates and the total area
 
     // Draw rectangles
-    chart.draw_series(data2.iter().map(|(x1, x2, y)| Rectangle::new([(*x2, *y), (*x1, 0.0)], &BLUE)))?;
+    chart.draw_series(
+        data2
+            .iter()
+            .map(|(x1, x2, y)| Rectangle::new([(*x2, *y), (*x1, 0.0)], &BLUE)),
+    )?;
 
     root.present()?;
     let output = chart.into_coord_trans();
@@ -46,7 +59,12 @@ pub fn draw(element: HtmlCanvasElement, func_str: &str, min_x: f32, max_x: f32,
 
 // Creates and does the math for creating all the rectangles under the graph
 #[inline(always)]
-fn integral_rectangles(min_x: f32, step: f32, num_interval: usize, func: &dyn Fn(f64) -> f64) -> (Vec<(f32, f32, f32)>, f32) {
+fn integral_rectangles(
+    min_x: f32,
+    step: f32,
+    num_interval: usize,
+    func: &dyn Fn(f64) -> f64,
+) -> (Vec<(f32, f32, f32)>, f32) {
     let mut area: f32 = 0.0; // sum of all rectangles' areas
     let mut tmp1: f32; // Top left Y value that's tested
     let mut tmp2: f32; // Top right Y value that's tested
@@ -55,12 +73,12 @@ fn integral_rectangles(min_x: f32, step: f32, num_interval: usize, func: &dyn Fn
     let mut x: f32; // X value of the left side of the rectangle
     let mut data2: Vec<(f32, f32, f32)> = Vec::new();
     for e in 0..num_interval {
-        x = ((e as f32)*step)+min_x;
+        x = ((e as f32) * step) + min_x;
 
         if x > 0.0 {
-            x2 = x+step;
+            x2 = x + step;
         } else {
-            x2 = x-step;
+            x2 = x - step;
         }
         tmp1 = func(x as f64) as f32;
         tmp2 = func(x2 as f64) as f32;
@@ -73,7 +91,7 @@ fn integral_rectangles(min_x: f32, step: f32, num_interval: usize, func: &dyn Fn
 
         // Add current rectangle's area to the total
         if !y.is_nan() {
-            area += y*step;
+            area += y * step;
             data2.push((x, x2, y));
         }
     }
diff --git a/src/lib.rs b/src/lib.rs
index 6439158..538ab1c 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -11,7 +11,7 @@ pub type DrawResult<T> = Result<T, Box<dyn std::error::Error>>;
 #[wasm_bindgen]
 pub struct Chart {
     convert: Box<dyn Fn((i32, i32)) -> Option<(f32, f32)>>,
-    area: f32
+    area: f32,
 }
 
 /// Result of screen to chart coordinates conversion.
@@ -23,8 +23,27 @@ pub struct Point {
 
 #[wasm_bindgen]
 impl Chart {
-    pub fn draw(canvas: HtmlCanvasElement, func: &str, min_x: f32, max_x: f32, min_y: f32, max_y: f32, num_interval: usize, resolution: i32) -> Result<Chart, JsValue> {
-        let output = func_plot::draw(canvas, func, min_x, max_x, min_y, max_y, num_interval, resolution).map_err(|err| err.to_string())?;
+    pub fn draw(
+        canvas: HtmlCanvasElement,
+        func: &str,
+        min_x: f32,
+        max_x: f32,
+        min_y: f32,
+        max_y: f32,
+        num_interval: usize,
+        resolution: i32,
+    ) -> Result<Chart, JsValue> {
+        let output = func_plot::draw(
+            canvas,
+            func,
+            min_x,
+            max_x,
+            min_y,
+            max_y,
+            num_interval,
+            resolution,
+        )
+        .map_err(|err| err.to_string())?;
         let map_coord = output.0;
         Ok(Chart {
             convert: Box::new(move |coord| map_coord(coord).map(|(x, y)| (x.into(), y.into()))),