diff --git a/examples/example_sine.rs b/examples/example_sine.rs
index 7ab0e1a..45da5b8 100644
--- a/examples/example_sine.rs
+++ b/examples/example_sine.rs
@@ -79,20 +79,18 @@ fn main() -> Result<(), Box<dyn Error>> {
         .draw()?;
 
     // add the first plot
-    let mut data1: Vec<(f64,f64)> = x_test.iter().zip(y_test_true.iter())
+    let data1: Vec<(f64,f64)> = x_test.iter().zip(y_test_true.iter())
         .map(|(x, y)| (x[0], y[0]))
         .collect();
-    data1.sort_by(|a, b| a.0.partial_cmp(&b.0).unwrap());
     chart
         .draw_series(LineSeries::new(data1, &RED)).unwrap()
         .label("true values")
         .legend(|(x, y)| PathElement::new(vec![(x, y), (x + 1, y)], &RED));
 
     // add the second plot
-    let mut data2: Vec<(f64,f64)> = x_test.iter().zip(y_test_pred.iter())
+    let data2: Vec<(f64,f64)> = x_test.iter().zip(y_test_pred.iter())
         .map(|(x, y)| (x[0], y[0]))
         .collect();
-    data2.sort_by(|a, b| a.0.partial_cmp(&b.0).unwrap());
     chart
         .draw_series(LineSeries::new(data2, &BLUE)).unwrap()
         .label("predicted values")