crates/plotters/README.md

# Plotters - A Rust drawing library focus on data plotting for both WASM and native applications  ������

<a href="https://crates.io/crates/plotters">
    <img style="display: inline!important" src="https://img.shields.io/crates/v/plotters.svg"></img>
</a>
<a href="https://docs.rs/plotters">
    <img style="display: inline!important" src="https://docs.rs/plotters/badge.svg"></img>
</a>
<a href="https://plotters-rs.github.io/rustdoc/plotters/">
	<img style="display: inline! important" src="https://img.shields.io/badge/docs-development-lightgrey.svg"></img>
</a>
<a href="https://travis-ci.org/38/plotters">
	<img style="display: inline! important" src="https://travis-ci.org/38/plotters.svg?branch=master"></img>
</a>
<a href="https://codecov.io/gh/38/plotters">
    <img style="display: inline! important" src="https://codecov.io/gh/38/plotters/branch/master/graph/badge.svg" />
</a>

Plotters is drawing library designed for rendering figures, plots, and charts, in pure rust. Plotters supports various types of back-ends,
including bitmap, vector graph, piston window, GTK/Cairo and WebAssembly.

- A new Plotters Developer's Guide is working in progress. The preview version is available at [here](https://plotters-rs.github.io/book).
- To try Plotters with interactive Jupyter notebook, or view [here](https://plotters-rs.github.io/plotters-doc-data/evcxr-jupyter-integration.html) for the static HTML version.
- To view the WASM example, go to this [link](https://plumberserver.com/plotters-wasm-demo/index.html)
- Currently we have all the internal code ready for console plotting, but a console based backend is still not ready. See [this example](https://github.com/38/plotters/blob/master/examples/console.rs) for how to plotting on Console with a customized backend.

## Gallery

To view the source code for each example, please click on the example image.

<a href="https://github.com/38/plotters/blob/master/examples/chart.rs">
    <img src="https://plotters-rs.github.io/plotters-doc-data/sample.png" class="galleryItem" width=200px></img>
</a>

<a href="https://github.com/38/plotters/blob/master/examples/stock.rs">
    <img src="https://plotters-rs.github.io/plotters-doc-data/stock.png" class="galleryItem" width=200px></img>
</a>

<a href="https://github.com/38/plotters/blob/master/examples/histogram.rs">
    <img src="https://plotters-rs.github.io/plotters-doc-data/histogram.png" class="galleryItem" width=200px></img>
</a>

<a href="https://github.com/38/plotters#quick-start">
    <img src="https://plotters-rs.github.io/plotters-doc-data/0.png" class="galleryItem" width=200px></img>
</a>

<a href="#">
	<img src="https://plotters-rs.github.io/plotters-doc-data/console-2.png" class="galleryItem" width=200px></img>
</a>

<a href="https://github.com/38/plotters/blob/master/examples/mandelbrot.rs">
    <img src="https://plotters-rs.github.io/plotters-doc-data/mandelbrot.png" class="galleryItem" width=200px></img>
</a>

<a href="https://github.com/38/plotters#trying-with-jupyter-evcxr-kernel-interactively">
    <img src="https://plotters-rs.github.io/plotters-doc-data/evcxr_animation.gif" class="galleryItem" width=200px></img>
</a>


<a href="https://github.com/38/plotters/tree/master/examples/piston-demo">
    <img src="https://plotters-rs.github.io/plotters-doc-data/plotters-piston.gif" class="galleryItem" width=200px></img>
</a>

<a href="https://github.com/38/plotters/blob/master/examples/normal-dist.rs">
    <img src="https://plotters-rs.github.io/plotters-doc-data/normal-dist.png" class="galleryItem" width=200px></img>
</a>

<a href="https://github.com/38/plotters/blob/master/examples/two-scales.rs">
    <img src="https://plotters-rs.github.io/plotters-doc-data/twoscale.png" class="galleryItem" width=200px></img>
</a>

<a href="https://github.com/38/plotters/blob/master/examples/matshow.rs">
    <img src="https://plotters-rs.github.io/plotters-doc-data/matshow.png" class="galleryItem" width=200px></img>
</a>

<a href="https://github.com/38/plotters/blob/master/examples/sierpinski.rs">
	<img src="https://plotters-rs.github.io/plotters-doc-data/sierpinski.png" class="galleryItem" width=200px></img>
</a>

<a href="https://github.com/38/plotters/blob/master/examples/normal-dist2.rs">
	<img src="https://plotters-rs.github.io/plotters-doc-data/normal-dist2.png" class="galleryItem" width=200px></img>
</a>

<a href="https://github.com/38/plotters/blob/master/examples/errorbar.rs">
	<img src="https://plotters-rs.github.io/plotters-doc-data/errorbar.png" class="galleryItem" width=200px></img>
</a>

<a href="https://github.com/38/plotters/blob/master/examples/slc-temp.rs">
	<img src="https://plotters-rs.github.io/plotters-doc-data/slc-temp.png" class="galleryItem" width=200px></img>
</a>

<a href="https://github.com/38/plotters/blob/master/examples/area-chart.rs">
	<img src="https://plotters-rs.github.io/plotters-doc-data/area-chart.png" class="galleryItem" width=200px></img>
</a>

<a href="https://github.com/38/plotters/blob/master/examples/snowflake.rs">
	<img src="https://plotters-rs.github.io/plotters-doc-data/snowflake.png" class="galleryItem" width=200px></img>
</a>

<a href="https://github.com/38/plotters/blob/master/examples/animation.rs">
	<img src="https://plotters-rs.github.io/plotters-doc-data/animation.gif" class="galleryItem" width=200px></img>
</a>

<a href="https://github.com/38/plotters/blob/master/examples/console.rs">
	<img src="https://plotters-rs.github.io/plotters-doc-data/console-example.png" class="galleryItem" width=200px></img>
</a>

<a href="https://github.com/38/plotters/blob/master/examples/console.rs">
	<img src="https://plotters-rs.github.io/plotters-doc-data/console.png" class="galleryItem" width=200px></img>
</a>

<a href="https://github.com/38/plotters/blob/master/examples/blit-bitmap.rs">
	<img src="https://plotters-rs.github.io/plotters-doc-data/blit-bitmap.png" class="galleryItem" width=200px></img>
</a>

<a href="https://github.com/38/plotters/blob/master/examples/boxplot.rs">
	<img src="https://plotters-rs.github.io/plotters-doc-data/boxplot.svg" class="galleryItem" width=200px></img>
</a>

<a href="https://github.com/38/plotters/blob/master/examples/3d-plot.rs">
	<img src="https://plotters-rs.github.io/plotters-doc-data/3d-plot.svg" class="galleryItem" width=200px></img>
</a>


## Table of Contents
  * [Gallery](#gallery)
  * [Quick Start](#quick-start)
  * [Trying with Jupyter evcxr Kernel Interactively](#trying-with-jupyter-evcxr-kernel-interactively)
  * [Interactive Tutorial with Jupyter Notebook](#interactive-tutorial-with-jupyter-notebook)
  * [Plotting in Rust](#plotting-in-rust)
  * [Plotting on HTML5 canvas with WASM Backend](#plotting-on-html5-canvas-with-wasm-backend)
  * [What types of figure are supported?](#what-types-of-figure-are-supported)
  * [Concepts by examples](#concepts-by-examples)
    + [Drawing Back-ends](#drawing-backends)
    + [Drawing Area](#drawing-area)
    + [Elements](#elements)
    + [Composable Elements](#composable-elements)
    + [Chart Context](#chart-context)
  * [Misc](#misc)
    + [Development Version](#development-version)
    + [Reducing Depending Libraries && Turning Off Backends](#reducing-depending-libraries--turning-off-backends)
    + [List of Features](#list-of-features)
  * [FAQ List](#faq-list)

## Quick Start

To use Plotters, you can simply add Plotters into your `Cargo.toml`
```toml
[dependencies]
plotters = "^0.3.0"
```

And the following code draws a quadratic function. `src/main.rs`,

```rust
use plotters::prelude::*;
fn main() -> Result<(), Box<dyn std::error::Error>> {
    let root = BitMapBackend::new("plotters-doc-data/0.png", (640, 480)).into_drawing_area();
    root.fill(&WHITE)?;
    let mut chart = ChartBuilder::on(&root)
        .caption("y=x^2", ("sans-serif", 50).into_font())
        .margin(5)
        .x_label_area_size(30)
        .y_label_area_size(30)
        .build_ranged(-1f32..1f32, -0.1f32..1f32)?;

    chart.configure_mesh().draw()?;

    chart
        .draw_series(LineSeries::new(
            (-50..=50).map(|x| x as f32 / 50.0).map(|x| (x, x * x)),
            &RED,
        ))?
        .label("y = x^2")
        .legend(|(x, y)| PathElement::new(vec![(x, y), (x + 20, y)], &RED));

    chart
        .configure_series_labels()
        .background_style(&WHITE.mix(0.8))
        .border_style(&BLACK)
        .draw()?;

    Ok(())
}
```

![](https://plotters-rs.github.io/plotters-doc-data/0.png)


## Trying with Jupyter evcxr Kernel Interactively

Plotters now supports integrate with `evcxr` and is able to interactively drawing plots in Jupyter Notebook.
The feature `evcxr` should be enabled when including Plotters to Jupyter Notebook.

The following code shows a minimal example of this.

```text
:dep plotters = { git = "https://github.com/38/plotters", default_features = false, features = ["evcxr"] }
extern crate plotters;
use plotters::prelude::*;

let figure = evcxr_figure((640, 480), |root| {
    root.fill(&WHITE);
    let mut chart = ChartBuilder::on(&root)
        .caption("y=x^2", ("Arial", 50).into_font())
        .margin(5)
        .x_label_area_size(30)
        .y_label_area_size(30)
        .build_ranged(-1f32..1f32, -0.1f32..1f32)?;

    chart.configure_mesh().draw()?;

    chart.draw_series(LineSeries::new(
        (-50..=50).map(|x| x as f32 / 50.0).map(|x| (x, x * x)),
        &RED,
    )).unwrap()
        .label("y = x^2")
        .legend(|(x,y)| PathElement::new(vec![(x,y), (x + 20,y)], &RED));

    chart.configure_series_labels()
        .background_style(&WHITE.mix(0.8))
        .border_style(&BLACK)
        .draw()?;
    Ok(())
});
figure
```

<img src="https://plotters-rs.github.io/plotters-doc-data/evcxr_animation.gif" width="450px"></img>

## Interactive Tutorial with Jupyter Notebook

*This tutorial is now working in progress and isn't complete*

Thanks to the evcxr, now we have an interactive tutorial for Plotters!
To use the interactive notebook, you must have Jupyter and evcxr installed on your computer.
Follow the instruction on [this page](https://github.com/google/evcxr/tree/master/evcxr_jupyter) below to install it.

After that, you should be able to start your Jupyter server locally and load the tutorial!

```bash
git clone https://github.com/38/plotters-doc-data
cd plotteres-doc-data
jupyter notebook
```

And select the notebook called `evcxr-jupyter-integration.ipynb`.

Also, there's a static HTML version of this notebook available at the [this location](https://plumberserver.com/plotters-docs/evcxr-jupyter-integration.html)

## Plotting in Rust

Rust is a perfect language for data visualization. Although there are many mature visualization libraries in many different languages.
But Rust is one of the best languages fits the need.

* **Easy to use** Rust has a very good iterator system built into the standard library. With the help of iterators,
Plotting in Rust can be as easy as most of the high-level programming languages. The Rust based plotting library
can be very easy to use.

* **Fast** If you need rendering a figure with trillions of data points,
Rust is a good choice. Rust's performance allows you to combine data processing step
and rendering step into a single application. When plotting in high-level programming languages,
e.g. Javascript or Python, data points must be down-sampled before feeding into the plotting
program because of the performance considerations. Rust is fast enough to do the data processing and visualization
within a single program. You can also integrate the
figure rendering code into your application handling a huge amount of data and visualize it in real-time.

* **WebAssembly Support** Rust is one of few the language with the best WASM support. Plotting in Rust could be
very useful for visualization on a web page and would have a huge performance improvement comparing to Javascript.

## Plotting on HTML5 canvas with WASM Backend

Plotters currently supports backend that uses the HTML5 canvas. To use the WASM support, you can simply use
`CanvasBackend` instead of other backend and all other API remains the same!

There's a small demo for Plotters + WASM under `examples/wasm-demo` directory of this repo.
To play with the deployed version, follow this [link](https://plumberserver.com/plotters-wasm-demo/index.html).


## What types of figure are supported?

Plotters is not limited to any specific type of figure.
You can create your own types of figures easily with the Plotters API.

But Plotters provides some builtin figure types for convenience.
Currently, we support line series, point series, candlestick series, and histogram.
And the library is designed to be able to render multiple figure into a single image.
But Plotter is aimed to be a platform that is fully extendable to support any other types of figure.

## Concepts by examples

### Drawing Back-ends
Plotters can use different drawing back-ends, including SVG, BitMap, and even real-time rendering. For example, a bitmap drawing backend.

```rust
use plotters::prelude::*;
fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Create a 800*600 bitmap and start drawing
    let mut backend = BitMapBackend::new("plotters-doc-data/1.png", (300, 200));
    // And if we want SVG backend
    // let backend = SVGBackend::new("output.svg", (800, 600));
    backend.draw_rect((50, 50), (200, 150), &RED, true)?;
    Ok(())
}
```

![](https://plotters-rs.github.io/plotters-doc-data/1.png)

### Drawing Area
Plotters uses a concept called drawing area for layout purpose.
Plotters support multiple integrating into a single image.
This is done by creating sub-drawing-areas.

Besides that, the drawing area also allows the customized coordinate system, by doing so, the coordinate mapping is done by the drawing area automatically.

```rust
use plotters::prelude::*;
fn main() -> Result<(), Box<dyn std::error::Error>> {
    let root_drawing_area =
        BitMapBackend::new("plotters-doc-data/2.png", (300, 200)).into_drawing_area();
    // And we can split the drawing area into 3x3 grid
    let child_drawing_areas = root_drawing_area.split_evenly((3, 3));
    // Then we fill the drawing area with different color
    for (area, color) in child_drawing_areas.into_iter().zip(0..) {
        area.fill(&Palette99::pick(color))?;
    }
    Ok(())
}
```

![](https://plotters-rs.github.io/plotters-doc-data/2.png)

### Elements

In Plotters, elements are build blocks of figures. All elements are able to draw on a drawing area.
There are different types of built-in elements, like lines, texts, circles, etc.
You can also define your own element in the application code.

You may also combine existing elements to build a complex element.

To learn more about the element system, please read the [element module documentation](./element/index.html).

```rust
use plotters::prelude::*;
fn main() -> Result<(), Box<dyn std::error::Error>> {
    let root = BitMapBackend::new("plotters-doc-data/3.png", (300, 200)).into_drawing_area();
    root.fill(&WHITE)?;
    // Draw an circle on the drawing area
    root.draw(&Circle::new(
        (100, 100),
        50,
        Into::<ShapeStyle>::into(&GREEN).filled(),
    ))?;
    Ok(())
}
```

![](https://plotters-rs.github.io/plotters-doc-data/3.png)

### Composable Elements

Besides the built-in elements, elements can be composed into a logic group we called composed elements.
When composing new elements, the upper-left corner is given in the target coordinate, and a new pixel-based
coordinate which has the upper-left corner defined as `(0,0)` is used for further element composition purpose.

For example, we can have an element which includes a dot and its coordinate.

```rust
use plotters::prelude::*;
use plotters::coord::types::RangedCoordf32;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let root = BitMapBackend::new("plotters-doc-data/4.png", (640, 480)).into_drawing_area();

    root.fill(&RGBColor(240, 200, 200))?;

    let root = root.apply_coord_spec(Cartesian2d::<RangedCoordf32, RangedCoordf32>::new(
        0f32..1f32,
        0f32..1f32,
        (0..640, 0..480),
    ));

    let dot_and_label = |x: f32, y: f32| {
        return EmptyElement::at((x, y))
            + Circle::new((0, 0), 3, ShapeStyle::from(&BLACK).filled())
            + Text::new(
                format!("({:.2},{:.2})", x, y),
                (10, 0),
                ("sans-serif", 15.0).into_font(),
            );
    };

    root.draw(&dot_and_label(0.5, 0.6))?;
    root.draw(&dot_and_label(0.25, 0.33))?;
    root.draw(&dot_and_label(0.8, 0.8))?;
    Ok(())
}
```

![](https://plotters-rs.github.io/plotters-doc-data/4.png)

### Chart Context

In order to draw a chart, Plotters need a data object built on top of the drawing area called `ChartContext`.
The chart context defines even higher level constructs compare to the drawing area.
For example, you can define the label areas, meshes, and put a data series onto the drawing area with the help
of the chart context object.

```rust
use plotters::prelude::*;
fn main() -> Result<(), Box<dyn std::error::Error>> {
    let root = BitMapBackend::new("plotters-doc-data/5.png", (640, 480)).into_drawing_area();
    root.fill(&WHITE);
    let root = root.margin(10, 10, 10, 10);
    // After this point, we should be able to draw construct a chart context
    let mut chart = ChartBuilder::on(&root)
        // Set the caption of the chart
        .caption("This is our first plot", ("sans-serif", 40).into_font())
        // Set the size of the label region
        .x_label_area_size(20)
        .y_label_area_size(40)
        // Finally attach a coordinate on the drawing area and make a chart context
        .build_cartesian_2d(0f32..10f32, 0f32..10f32)?;

    // Then we can draw a mesh
    chart
        .configure_mesh()
        // We can customize the maximum number of labels allowed for each axis
        .x_labels(5)
        .y_labels(5)
        // We can also change the format of the label text
        .y_label_formatter(&|x| format!("{:.3}", x))
        .draw()?;

    // And we can draw something in the drawing area
    chart.draw_series(LineSeries::new(
        vec![(0.0, 0.0), (5.0, 5.0), (8.0, 7.0)],
        &RED,
    ))?;
    // Similarly, we can draw point series
    chart.draw_series(PointSeries::of_element(
        vec![(0.0, 0.0), (5.0, 5.0), (8.0, 7.0)],
        5,
        &RED,
        &|c, s, st| {
            return EmptyElement::at(c)    // We want to construct a composed element on-the-fly
            + Circle::new((0,0),s,st.filled()) // At this point, the new pixel coordinate is established
            + Text::new(format!("{:?}", c), (10, 0), ("sans-serif", 10).into_font());
        },
    ))?;
    Ok(())
}
```

![](https://plotters-rs.github.io/plotters-doc-data/5.png)

## Misc

### Development Version

To use the latest development version, pull https://github.com/38/plotters.git. In `Cargo.toml`

```toml
[dependencies]
plotters = { git = "https://github.com/38/plotters.git" }
```

### Reducing Depending Libraries && Turning Off Backends
Plotters now supports use features to control the backend dependencies. By default, `BitMapBackend` and `SVGBackend` are supported,
use `default_features = false` in the dependency description in `Cargo.toml` and you can cherry-pick the backend implementations.

- `svg` Enable the `SVGBackend`
- `bitmap` Enable the `BitMapBackend`

For example, the following dependency description would avoid compiling with bitmap support:

```toml
[dependencies]
plotters = { git = "https://github.com/38/plotters.git", default_features = false, features = ["svg"] }
```

The library also allows consumers to make use of the [`Palette`](https://crates.io/crates/palette/) crate's color types by default.
This behavior can also be turned off by setting `default_features = false`.

### List of Features

This is the full list of features that is defined by `Plotters` crate.
Use `default_features = false` to disable those default enabled features,
and then you should be able to cherry-pick what features you want to include into `Plotters` crate.
By doing so, you can minimize the number of dependencies down to only `itertools` and compile time is less than 6s.

The following list is a complete list of features that can be opt in and out.

- Tier 1 drawing backends

| Name    |  Description | Additional Dependency |Default?|
|---------|--------------|--------|------------|
| bitmap\_encoder  | Allow `BitMapBackend` save the result to bitmap files | image, rusttype, font-kit | Yes |
| svg\_backend     | Enable `SVGBackend` Support | None | Yes |
| bitmap\_gif| Opt-in GIF animation Rendering support for `BitMapBackend`, implies `bitmap` enabled | gif | Yes |

- Font manipulation features

| Name    |  Description | Additional Dependency |Default?|
|---------|--------------|--------|------------|
| ttf | Allows TrueType font support | rusttype, font-kit | Yes |

- Coordinate features

| Name    |  Description | Additional Dependency |Default?|
|---------|--------------|--------|------------|
| datetime | Eanble the date and time coordinate support | chrono | Yes |

- Element, series and util functions

| Name    |  Description | Additional Dependency |Default?|
|---------|--------------|--------|------------|
| errorbar | The errorbar element support | None | Yes |
| candlestick | The candlestick element support | None | Yes |
| boxplot | The boxplot element support | None | Yes |
| area\_series | The area series support | None | Yes |
| line\_series | The line series support | None | Yes |
| histogram | The histogram series support | None | Yes |
| point\_series| The point series support | None | Yes |

- Misc

| Name    |  Description | Additional Dependency |Default?|
|---------|--------------|--------|------------|
| deprecated\_items | This feature allows use of deprecated items which is going to be removed in the future | None | Yes |
| debug | Enable the code used for debugging | None | No |


## FAQ List

* Why does the WASM example break on my machine ?

	The WASM example requires using `wasm32` target to build. Using `cargo build` is likely to use the default target
	which in most of the case is any of the x86 target. Thus you need add `--target=wasm32-unknown-unknown` in the cargo
	parameter list  to build it.

* How to draw text/circle/point/rectangle/... on the top of chart ?

	As you may realized, Plotters is a drawing library rather than a traditional data plotting library,
	you have the freedom to draw anything you want on the drawing area.
	Use `DrawingArea::draw` to draw any element on the drawing area.