Struct Curve

Source

pub struct Curve { /* private fields */ }

Expand description

Generates a curve (aka line-plot) given two arrays (x,y)

See Matplotlib’s documentation

§Notes

This struct corresponds to the plot function of Matplotlib.
You may plot a Scatter plot by setting line_style = “None”

§Examples

§Using methods to set the points

use plotpy::{Curve, Plot, StrError};
use std::f64::consts::PI;

fn main() -> Result<(), StrError> {
    // configure curve
    let mut curve = Curve::new();
    curve.set_line_width(2.0);

    // add points
    const N: usize = 30;
    curve.points_begin();
    for i in 0..N {
        let x = (i as f64) * 2.0 * PI / ((N - 1) as f64);
        let y = f64::sin(x);
        curve.points_add(x, y);
    }
    curve.points_end();

    // add curve to plot
    let mut plot = Plot::new();
    plot.add(&curve).grid_and_labels("x", "y");

    // configure multiple-of-pi formatter
    let minor_every = PI / 12.0;
    plot.set_ticks_x_multiple_of_pi(minor_every);

    // save figure
    plot.save("/tmp/plotpy/doc_tests/doc_curve_methods.svg")?;
    Ok(())
}

§Using Vector with point data

use plotpy::{linspace, Curve, Plot, StrError};

fn main() -> Result<(), StrError> {
    // generate (x,y) points
    let x = linspace(-1.0, 1.0, 21);
    let y: Vec<_> = x.iter().map(|v| 1.0 / (1.0 + f64::exp(-5.0 * *v))).collect();

    // configure curve
    let mut curve = Curve::new();
    curve
        .set_label("logistic function")
        .set_line_alpha(0.8)
        .set_line_color("#5f9cd8")
        .set_line_style("-")
        .set_line_width(5.0)
        .set_marker_color("#eeea83")
        .set_marker_every(5)
        .set_marker_line_color("#da98d1")
        .set_marker_line_width(2.5)
        .set_marker_size(20.0)
        .set_marker_style("*");

    // draw curve
    curve.draw(&x, &y);

    // add curve to plot
    let mut plot = Plot::new();
    plot.add(&curve).set_num_ticks_y(11).grid_labels_legend("x", "y");

    // save figure
    plot.save("/tmp/plotpy/doc_tests/doc_curve.svg")?;
    Ok(())
}

§(twinx) Plot two vertical axes with different scales

use plotpy::{linspace, Curve, Plot, StrError};
use std::f64::consts::PI;

fn main() -> Result<(), StrError> {
    // data
    let np = 201;
    let mut x = vec![0.0; np];
    let mut y1 = vec![0.0; np];
    let mut y2 = vec![0.0; np];
    let dx = 4.0 / (np as f64);
    for i in 0..np {
        x[i] = (i as f64) * dx;
        y1[i] = f64::exp(x[i]);
        y2[i] = f64::sin(2.0 * PI * x[i]);
    }

    // curve
    let mut curve = Curve::new();
    curve.set_line_color("red").draw(&x, &y1);
    curve.set_line_color("blue").draw_with_twin_x(&y2);

    // add curve to plot
    let mut plot = Plot::new();
    plot.add(&curve) // must occur before set twinx options
        .grid_and_labels("time (s)", "exp function")
        .set_label_x_color("green")
        .set_label_y_color("red")
        .set_label_y_twinx("sin function")
        .set_label_y_twinx_color("blue");

    // save figure
    plot.save("/tmp/plotpy/doc_tests/doc_curve_twinx.svg")?;
    Ok(())
}