plotters/examples/normal-dist.rs

use plotters::prelude::*;

use rand::SeedableRng;
use rand_distr::{Distribution, Normal};
use rand_xorshift::XorShiftRng;

const OUT_FILE_NAME: &str = "plotters-doc-data/normal-dist.png";
fn main() -> Result<(), Box<dyn std::error::Error>> {
    let root = BitMapBackend::new(OUT_FILE_NAME, (1024, 768)).into_drawing_area();

    root.fill(&WHITE)?;

    let sd = 0.13;

    let random_points: Vec<(f64, f64)> = {
        let norm_dist = Normal::new(0.5, sd).unwrap();
        let mut x_rand = XorShiftRng::from_seed(*b"MyFragileSeed123");
        let mut y_rand = XorShiftRng::from_seed(*b"MyFragileSeed321");
        let x_iter = norm_dist.sample_iter(&mut x_rand);
        let y_iter = norm_dist.sample_iter(&mut y_rand);
        x_iter.zip(y_iter).take(5000).collect()
    };

    let areas = root.split_by_breakpoints([944], [80]);

    let mut x_hist_ctx = ChartBuilder::on(&areas[0])
        .y_label_area_size(40)
        .build_cartesian_2d((0.0..1.0).step(0.01).use_round().into_segmented(), 0..250)?;
    let mut y_hist_ctx = ChartBuilder::on(&areas[3])
        .x_label_area_size(40)
        .build_cartesian_2d(0..250, (0.0..1.0).step(0.01).use_round())?;
    let mut scatter_ctx = ChartBuilder::on(&areas[2])
        .x_label_area_size(40)
        .y_label_area_size(40)
        .build_cartesian_2d(0f64..1f64, 0f64..1f64)?;
    scatter_ctx
        .configure_mesh()
        .disable_x_mesh()
        .disable_y_mesh()
        .draw()?;
    scatter_ctx.draw_series(
        random_points
            .iter()
            .map(|(x, y)| Circle::new((*x, *y), 2, GREEN.filled())),
    )?;
    let x_hist = Histogram::vertical(&x_hist_ctx)
        .style(GREEN.filled())
        .margin(0)
        .data(random_points.iter().map(|(x, _)| (*x, 1)));
    let y_hist = Histogram::horizontal(&y_hist_ctx)
        .style(GREEN.filled())
        .margin(0)
        .data(random_points.iter().map(|(_, y)| (*y, 1)));
    x_hist_ctx.draw_series(x_hist)?;
    y_hist_ctx.draw_series(y_hist)?;

    // 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(())
}
#[test]
fn entry_point() {
    main().unwrap()
}