1 files changed, 98 insertions, 0 deletions
diff --git a/vendor/plotters/examples/errorbar.rs b/vendor/plotters/examples/errorbar.rs
new file mode 100644
index 000000000..75c5dbea0
--- /dev/null
+++ b/vendor/plotters/examples/errorbar.rs
@@ -0,0 +1,98 @@
+use plotters::prelude::*;
+
+use rand::SeedableRng;
+use rand_distr::{Distribution, Normal};
+use rand_xorshift::XorShiftRng;
+
+use itertools::Itertools;
+
+use num_traits::sign::Signed;
+
+const OUT_FILE_NAME: &'static str = "plotters-doc-data/errorbar.png";
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let data = generate_random_data();
+    let down_sampled = down_sample(&data[..]);
+
+    let root = BitMapBackend::new(OUT_FILE_NAME, (1024, 768)).into_drawing_area();
+
+    root.fill(&WHITE)?;
+
+    let mut chart = ChartBuilder::on(&root)
+        .caption("Linear Function with Noise", ("sans-serif", 60))
+        .margin(10)
+        .set_label_area_size(LabelAreaPosition::Left, 40)
+        .set_label_area_size(LabelAreaPosition::Bottom, 40)
+        .build_cartesian_2d(-10f64..10f64, -10f64..10f64)?;
+
+    chart.configure_mesh().draw()?;
+
+    chart
+        .draw_series(LineSeries::new(data, &GREEN.mix(0.3)))?
+        .label("Raw Data")
+        .legend(|(x, y)| PathElement::new(vec![(x, y), (x + 20, y)], &GREEN));
+
+    chart.draw_series(LineSeries::new(
+        down_sampled.iter().map(|(x, _, y, _)| (*x, *y)),
+        &BLUE,
+    ))?;
+
+    chart
+        .draw_series(
+            down_sampled.iter().map(|(x, yl, ym, yh)| {
+                ErrorBar::new_vertical(*x, *yl, *ym, *yh, BLUE.filled(), 20)
+            }),
+        )?
+        .label("Down-sampled")
+        .legend(|(x, y)| PathElement::new(vec![(x, y), (x + 20, y)], &BLUE));
+
+    chart
+        .configure_series_labels()
+        .background_style(WHITE.filled())
+        .draw()?;
+
+    // To avoid the IO failure being ignored silently, we manually call the present function
+    root.present().expect("Unable to write result to file, please make sure 'plotters-doc-data' dir exists under current dir");
+    println!("Result has been saved to {}", OUT_FILE_NAME);
+
+    Ok(())
+}
+
+fn generate_random_data() -> Vec<(f64, f64)> {
+    let norm_dist = Normal::new(0.0, 1.0).unwrap();
+    let mut x_rand = XorShiftRng::from_seed(*b"MyFragileSeed123");
+    let x_iter = norm_dist.sample_iter(&mut x_rand);
+    x_iter
+        .take(20000)
+        .filter(|x| x.abs() <= 4.0)
+        .zip(-10000..10000)
+        .map(|(yn, x)| {
+            (
+                x as f64 / 1000.0,
+                x as f64 / 1000.0 + yn * x as f64 / 10000.0,
+            )
+        })
+        .collect()
+}
+
+fn down_sample(data: &[(f64, f64)]) -> Vec<(f64, f64, f64, f64)> {
+    let down_sampled: Vec<_> = data
+        .iter()
+        .group_by(|x| (x.0 * 1.0).round() / 1.0)
+        .into_iter()
+        .map(|(x, g)| {
+            let mut g: Vec<_> = g.map(|(_, y)| *y).collect();
+            g.sort_by(|a, b| a.partial_cmp(b).unwrap());
+            (
+                x,
+                g[0],
+                g.iter().sum::<f64>() / g.len() as f64,
+                g[g.len() - 1],
+            )
+        })
+        .collect();
+    down_sampled
+}
+#[test]
+fn entry_point() {
+    main().unwrap()
+}