Lines and markers¶

use std::f64::consts::PI;

use ironlab::prelude::*;

pub const TITLE: &str = "Lines and markers";
pub const DESCRIPTION: &str = "A damped oscillation plotted as lines with markers at the samples, a dashed line \
     without markers and a dotted envelope. Series with display names appear in the legend, and the axis labels are \
     typeset with LaTeX.";

pub fn figure() -> Figure {
    let t = linspace(0.0, 4.0 * PI, 49);
    // A cosine and a sine whose amplitudes both decay within the envelope e^(-t/4).
    let envelope: Vec<f64> = t.iter().map(|t| (-t / 4.0).exp()).collect();
    let damped_cosine: Vec<f64> = t.iter().map(|t| (-t / 4.0).exp() * t.cos()).collect();
    let damped_sine: Vec<f64> = t.iter().map(|t| (-t / 4.0).exp() * t.sin()).collect();

    let mut fig = Figure::new()
        .size_mm(160.0, 100.0)
        .title("A damped oscillator");
    let mut ax = fig.axes(0, 0);
    ax.plot(&t, &damped_cosine)
        .display_name(r"$e^{-t/4} \cos t$")
        .marker(Marker::Circle)
        .marker_size(3.5);
    ax.plot(&t, &damped_sine)
        .display_name(r"$e^{-t/4} \sin t$")
        .dash(Dash::Dashed)
        .line_width(1.0);
    ax.plot(&t, &envelope)
        .display_name(r"$e^{-t/4}$")
        .color(Color::rgb(0.4, 0.4, 0.4))
        .dash(Dash::Dotted);
    ax.xlabel(r"Time $t$ (s)")
        .ylabel(r"Displacement $x(t)$ (m)")
        .grid(true)
        .legend(LegendLocation::NorthEast);
    fig
}