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> { 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::() / g.len() as f64, g[g.len() - 1], ) }) .collect(); down_sampled } #[test] fn entry_point() { main().unwrap() }