Background

Now the discrete range trait doesn't seem clean because of the following issue:

• No bound check, the next_value and previous_value requires always returns a value
• Unknown number of distinct values
• Linspace coord should be a discrete range, however this can't be used in Histogram since the hash table requires Equal trait but f64 doesn't impl the trait.

However, all the discrete range is equivalent to a integer range, thus we doesn't actually need put any restriction on the traits for the actual values. (Later we may use an array as an discrete coordinate and lifting the trait bound will make this possible)

Drawbacks

In order to know the number of values and handle the bound correctly, we have to make most of the RangeParam not an unit type, and this will makes Histogram::new unsable to applied to most of the coord types. Thus this should be considered as an breaking change.

Description:
The plot for '1D Gaussian Distribution' has a typo. It actually reads '1D Guassian Distribution'

The image with the typo can be seen here

Fix:
The typo is caused by line 25 of the file plotters/examples/normal-dist2.rs

Can't build the example, as following:

zmant@zmant-PC:~/Projects/rust_demo$ cargo build 
   Compiling servo-fontconfig-sys v4.0.7
error: failed to run custom build command for `servo-fontconfig-sys v4.0.7`
process didn't exit successfully: `/home/zmant/Projects/rust_demo/target/debug/build/servo-fontconfig-sys-ab35303d25e9c957/build-script-build` (exit code: 101)
--- stdout
cd /home/zmant/Projects/rust_demo/target/debug/build/servo-fontconfig-sys-d6a6c48eec147b8b/out && \
	CC="gcc" \
	AR="ar" \
	FREETYPE_CFLAGS="" \
	FREETYPE_LIBS="" \
	CFLAGS=""" -fPIC" \
	/home/zmant/.cargo/registry/src/code.aliyun.com-738b7dba08a2a41e/servo-fontconfig-sys-4.0.7/configure \
	--disable-docs \
	--disable-shared \
	 \
	--host=x86_64-unknown-linux-gnu --sysconfdir=/etc --localstatedir=/var
.........
checking for FT_Bitmap_Size.y_ppem... yes
checking for EXPAT... no
checking expat.h usability... no
checking expat.h presence... no
checking for expat.h... no
checking xmlparse.h usability... no
checking xmlparse.h presence... no
checking for xmlparse.h... no
makefile.cargo:83: recipe for target '/home/zmant/Projects/rust_demo/target/debug/build/servo-fontconfig-sys-d6a6c48eec147b8b/out/Makefile' failed

--- stderr
configure: error: 
*** expat is required. or try to use --enable-libxml2
make: *** [/home/zmant/Projects/rust_demo/target/debug/build/servo-fontconfig-sys-d6a6c48eec147b8b/out/Makefile] Error 1
thread 'main' panicked at 'assertion failed: Command::new("make").env("MAKEFLAGS",
                         env::var("CARGO_MAKEFLAGS").unwrap_or_default()).args(&["-R",
                                                                                 "-f",
                                                                                 "makefile.cargo"]).status().unwrap().success()', /home/zmant/.cargo/registry/src/code.aliyun.com-738b7dba08a2a41e/servo-fontconfig-sys-4.0.7/build.rs:20:5
note: Run with `RUST_BACKTRACE=1` environment variable to display a backtrace.

The dependencies:

zmant@zmant-PC:~/Projects/rust_demo$ cat Cargo.toml 
[package]
name = "rust_demo"
version = "0.1.0"
authors = ["zmant"]
edition = "2018"

[dependencies]
plotters =  "0.2"

Did I miss something？

In this example, if I change x_labels(5) to x_labels(0), the labels don't go away. The latter is basically equivalent to x_labels(1). I want to be able to remove the labels to achieve something like this and this.

Hello, I'm using seed for a frontend project, and want to use plotters to render graphs.
Seed doesn't allow direct access to the elements that it creates, so drawing to a canvas through seed doesn't work.

Right now I'm using plotlib for generating graphs. I render an svg to a buffer and convert it into a blob. Then I create an <image> that points to the blob. This doesn't work in plotters because the svg and bitmap backends are completely disabled for wasm.

The easiest fix is to simply allow the in memory targets for the svg and bitmap backends in wasm and only disable the file target.

Another fix might be too create a backend specific to seed, or to have some way of accepting a canvas from seed. I think this might be a better route in the long term, but I'm not exactly sure how it would work.

What is the feature ?

Use of slice as a discrete coordinate. We can do

.build_ranged(["foo", "bar", "baz"], 0..100)

Ive faced with neccesity to divide drawing area using relative value to canvas size.
Lets say i want to split canvas vertically in proportion 70%/30%.
Or i want lower drawing area to be of a fixed height(200px) but canvas size is dynamically adjusted.
Any advice?

Noticed that i cant draw Histogram with timeseries.

error[E0277]: the trait bound `plotters::coord::datetime::RangedDateTime<chrono::offset::utc::Utc>: plotters::coord::ranged::DescreteRanged` is not satisfied
   --> src\common\chart\mod.rs:189:24
    |
189 |         let buy_vols = Histogram::vertical(&vols_chart)
    |                        ^^^^^^^^^^^^^^^^^^^ the trait `plotters::coord::ranged::DescreteRanged` is not implemented for `plotters::coord::datetime::RangedDateTime<chrono::offset::utc::Utc>`

Any info on using WASM+WebGL+Plotters? Is it possible?

• What is the feature ?

Now we just demonstrated it's possible draw plots on console without actually changing the API in this example.

But it seems we still needs to tweak something and make it a built-in backend.

• Why do you need the feature ?

Plotting in console may be very interesting for someone who use SSH which doesn't have a easy to access the image.

• What is the use case ? See above

What is the feature ?

Nested coordinate, which means it's a discrete coordinate but for each value, it attached another nested coordinate system on that.

(Optional) Why this feature is useful and how people would use the feature ?

While I make the PR for criterion, this idea comes out. Check out the following example for details:

Each of the tick mark has a nested coordinate system ranged from -1.0 to +1.0

(Optional) Additional Information

Blockers: This would be blocked by this issue #80 . Unless we have a reasonable abstraction on discrete coordinate, this is tricky to accomplish.

Background

Similar to #55. In addition, it would be nice to make use of multiple cores when rendering real time sub-graphs.

• What is the feature ?

When doing:

let root = BitMapBackend::with_buffer(&mut texture.data, texture.dimension).into_drawing_area();
let (upper, lower) = root.split_vertically(300);

It would be nice if upper and lower could be used from separate threads to render both sub-graphs in parallel, since they should not share any overlapping area.

• Why do you need the feature ?
• What is the use case ?

See above, to improve multi-core utilization when doing software rendering of real time graphs.

Addition Information

Plotters should not do the multithreading itself and should remain lightweight. Instead, I as the API user want to be in charge which threading library I use, e.g., when rendering sub-graphs.

The wasm-demo does not currently build.

error[E0433]: failed to resolve: use of undeclared type or module `CanvasBackend`
 --> src/func_plot.rs:8:19
  |
8 |     let backend = CanvasBackend::new(element).unwrap();
  |                   ^^^^^^^^^^^^^ use of undeclared type or module `CanvasBackend`

error[E0433]: failed to resolve: use of undeclared type or module `CanvasBackend`
  --> src/mandelbrot.rs:33:19
   |
33 |     let backend = CanvasBackend::new(element).unwrap();
   |                   ^^^^^^^^^^^^^ use of undeclared type or module `CanvasBackend`

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0433`.
error: Could not compile `wasm-demo`.

To learn more, run the command again with --verbose.

• What is the feature ?
  We should support different pixel format for bitmap backend.

• Why do you need the feature ?

If we want to use Plotters to manipulate a framebuffer, the most commonly used frame buffer pixel format is BGRX. Currently we have to draw the RGB buffer and convert the pixel format.

• What is the use case ?

See above

• Additional Information

#66 This PR is actually trying to address this. But we definitely should have some more clean and nice way to do this inplace

See discuss under issue #31

I'd like to improve wasm demo a bit. In particular I'd like to move all inline styles to already existing css file, extract js code to a separate file, use es6+ in js code, replace setTimeout with requestAnimationFrame and thus remove double buffering example.

Also I'd like to make a realtime rendered demo.
If you think this sounds good, I can start working on that ;)

Unless I missed it, there is no way to create interactive plots for wasm or native.

Describe the bug
On OSX, using generic font family settings such as "serif" will result an error FontNotFound

To Reproduce

   area.draw_text("Hello",  "serif".into_font())

Version Information
Latest master

• What is the feature ?

Currently, AreaSeries colors the area from Path/LineSeries to baseline. This is done with Polygon. It would be nice to have two different colors for areas above and below.

• Why do you need the feature ?

This makes some graphs much nicer to read.

• What is the use case ?

Market microstructure visualization

• Additional Information

Color buy volume GREEN.mix(0.1) and sell volume RED.mix(0.1)

This requires implementing a method called evcxr_display which returns HTML.

See: https://github.com/google/evcxr/blob/master/evcxr_jupyter/README.md#custom-output

I'm having error on this:

        price_chart
            .draw_series(PointSeries::new(
                (0..self.timecache.len()).map(|x| (x, self.timecache[x].2)),
                1,
                &RED,
            )).unwrap();

What coudl it be?

error[E0282]: type annotations needed
   --> src\scenes\instances\components\chart\mod.rs:108:14
    |
108 |             .draw_series(PointSeries::new(
    |              ^^^^^^^^^^^ cannot infer type for `E`

Hello! This is a fantastic crate.

Currently, it seems like it's not possible to configure the stroke width in plotters (this comment suggests as much).

This is a fairly straightforward feature to add to the vector back-ends and I'd be happy to submit a pull request implementing it for piston, svg, and canvas once the API is figured out.

I noticed that in some cases (when chart is pretty small), lets say secondary coord with relative height 0.15 of main area height, there is situation when no labels are showing up even if there is range of only 0.0...0.1 and we have only 2 (and more) different values (0.05, 0.1). When we have only 1 value its showing correctly, if more nothing...
.y_labels(5/10)

We need some default global setting, such as default styles for different things, etc.

Background

I am using plotters together with minifb to visualize real time sensor data. The combination is awesome, since both libraries are very lightweight, and it's easy to do portable, real-time UIs.

One implication is that all rendering is purely SW; plotters writes into a byte array, which minifb uses to update the frame buffer.

Unfortunately, in that process as of today, data has to be copied around multiple times for no reason other than plumbing, which costs precious CPU cycles.

Feature Request

• What is the feature ?

Plotters' BitMapBackend should accept a user-provided byte buffer to render into; instead of allocating its own.

• Why do you need the feature ?
• What is the use case ?

See above; to reduce allocation, improve performance.

Currently canvas backend only supports taking canvas by Id.

But for both seed support described in issue #16 and dual buffer rendering, it should be better to have canavs backend taking the canvas javascript object directly.

I just thought it might be of interest to start a discussion about this. I noticed this crate uses it's own simplistic color definitions, so to my mind came the possibility of using the palette crate which would allow users to define and use colors in a very great spectrum.

Lets say i have chart with given coordinate system.
I need to draw a dotted (horizontal) line through whole chart using one y-coord.
And i want every dot to be 5px length.
What is most efficient way?

Move PR #27 to here, since it's not actually a PR.

The piston demo builds, but panics immediately

aaron-mini:piston-demo aholtzma$ RUST_BACKTRACE=1 ./target/release/piston-demo
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Custom { kind: Other, error: StringError("Not supported") }', src/libcore/result.rs:999:5
stack backtrace:
   0: std::sys::unix::backtrace::tracing::imp::unwind_backtrace
   1: std::sys_common::backtrace::_print
   2: std::panicking::default_hook::{{closure}}
   3: std::panicking::default_hook
   4: std::panicking::rust_panic_with_hook
   5: std::panicking::continue_panic_fmt
   6: rust_begin_unwind
   7: core::panicking::panic_fmt
   8: core::result::unwrap_failed
   9: <alloc::vec::Vec<T> as alloc::vec::SpecExtend<T,I>>::from_iter
  10: piston_demo::main
  11: std::rt::lang_start::{{closure}}
  12: std::panicking::try::do_call
  13: __rust_maybe_catch_panic
  14: std::rt::lang_start_internal
  15: main

This is running on MacOS Mojave.

Great work with the library. I was trying to run the examples on my Windows machine.
chart.exe is generated by running cargo run --example chart but I get the following error on running that exe:
Error: BackendError(DrawingError(IoError(Os { code: 3, kind: NotFound, message: "The system cannot find the path specified." })))

Also, running the webassembly demo locally does not work. It is not able to load pkg/wasm-demo.js.

What is the feature ?

Ability to control color of individual bars in the histogram.

Why do you need the feature / What is the use case ?

Take a look at this plot:

It shows daily data. I'd like to color 6th and 7th bars with different color, so it would be easy to see weekends.

Then it would be also nice to have a better control over ticks placement. For instance I'd like to put ticks every 7 bars to highlight full weeks.

When building the font name database, plotters is extremely sensitive to fonts that it cannot load. Plotters bails with "Error: BackendError(FontError(FontLoadError(UnrecognizedFormat)))" even if the font that I'm actually requesting is already loaded.

In my current case and on a system I don't control, there's an OTF formatted font installed in a system directory that breaks plotters for me. If I run it at my local system and temporarily remove the font in question, plotters works fine.

I was expecting that plotters would just skip loading "unloadable" fonts in the look-up table, instead it panics with the above error. Skipping would at least allow plotters to work with the fonts that are actually loadable.

Support for a gtk backend?

Describe the bug
When using AreaSeries the backend is required to be 'static, e.g. BitmapBackend<'static>. This has a number of limitations, the simplest of which is that a filename passed to the backend must have a static lifetime. This is not the case with other series such as LineSeries. It seems AreaSeries takes a reference to the backend while others do not.

To Reproduce
I modified the area chart example from:

let root = BitMapBackend::new("plotters-doc-data/area-chart.png", (1024, 768)).into_drawing_area();

to:

let filename = "plotters-doc-data/area-chart.png".to_string();
let root = BitMapBackend::new(&filename, (1024, 768)).into_drawing_area();

After doing this the example would no longer compile. This reproduces my problem exactly.

Version Information
Both master and 0.2.9.

See discussion under #56 for detials

Just realized a different thing, I tried your benchmark with a CPU profiler.
The result is so shocking: 25% of the time is spend to handle the Result types.
I try to remove one question mark from the rasterizer, it turns out a 10% speed up.

--

Local repo:

test sine_640_480                                  ... bench:   4,188,667 ns/iter (+/- 338,945)
test sine_640_480_2_horizontal_subgraphs_draw_both ... bench:   4,609,418 ns/iter (+/- 407,366)
test sine_640_480_2_horizontal_subgraphs_draw_one  ... bench:   2,298,113 ns/iter (+/- 461,527)
test sine_640_480_2_horizontal_subgraphs_fake_blit ... bench:     270,355 ns/iter (+/- 53,794)

0.2.8:

test sine_640_480                                  ... bench:   7,277,665 ns/iter (+/- 3,636,985)
test sine_640_480_2_horizontal_subgraphs_draw_both ... bench:   8,129,140 ns/iter (+/- 937,515)
test sine_640_480_2_horizontal_subgraphs_draw_one  ... bench:   4,303,821 ns/iter (+/- 255,423)
test sine_640_480_2_horizontal_subgraphs_fake_blit ... bench:     288,119 ns/iter (+/- 102,912)

--

Update, I refactored two question mark to is_err it turns out 50% speed up.

Is it possible to divide plot on internally nested charts which have one common X-axis and two different Y-axes?
Like here:

Is it possible to build chart with seconds or even milliseconds on X-axis? It would be nice to split it by some nice ranges like 5sec or 1/5min?

This looks like an awesome crate, thanks for creating it! I've copied the wasm-example code verbatim into a repository of my own but am getting a module error in the start_plotting method.

failed to resolve: use of undeclared type or module `CanvasBackend`

use of undeclared type or module `CanvasBackend`rustc(E0433)
lib.rs(8, 17): use of undeclared type or module `CanvasBackend

Any ideas what to do here? I'm pretty new to Rust so sorry if I'm missing something obvious.

Lets say i have one very big data vector with stable items array:
[[datetime, price1, price2, price3],[...][...],...]
To draw 3 lines with prices:1,2,3 i should iterate over vector 3 times to crate 3 vectors with [datetime,price1],[datetime,price2],[datetime,price3]
Would it be more efficient to give a ref on a main vector to plotters and then set 3 accessors funcs to let plotters now how to pull out particular [x;y] for specified chart type;

It could looks like:

type DataVectorItem = (datetime_type,price_type,price_type,price_type);
ChartBuilder::on(root)
    .data(&vector)
    .build_ranged(time_start..time_end, min..max).unwrap();

        chart
            .draw_series(LineSeries::new(
                |data_item:&DataVectorItem| => (x,y) { (data_item.0,data_item.3) }, // accessor func
                &RGBColor(45,140,220).mix(0.9),
            )).unwrap();

What you say?

This is a great resource. Thank you. Being new to Rust, I was looking forward to playing with the language in jupyter. This lib provides a key ingredient. This said, I was trying to parse through the example code to draw different charts to no avail. Do you think you could provide another example or two for me to use to figure out how to use the lib in jupyter? To be clear, the example you provide, works as promised. Thank you in advance. - E

I can't get plotters to render the x_labels for large timespans, no matter how I tweak the parameters. For short timespans it seems fine:

Longer timespans don't show anything:

The code I use for generating the graphs:

fn part_graph_view(part: &Part) -> Result<Node<Msg>, Box<dyn std::error::Error>> {
    use plotters::prelude::*;

    let mut buffer = Vec::new();
    {
        let svg = SVGBackend::with_buffer(&mut buffer, (480, 320));
        let root = svg.into_drawing_area();
        root.fill(&WHITE).unwrap();

        let beginning = Utc.from_utc_date(&part.defined);
        let today = Utc::today();
        let (_qty, max_qty, quantities, counts) = part.entries.iter().fold(
            (0_u64, 0_u64, Vec::new(), Vec::new()),
            |(qty, max_qty, mut quantities, mut counts), entry| {
                let qty = match &entry.directive {
                    Directive::Add(d) => {
                        let qty = qty.saturating_add(d.amount);
                        quantities.push((Utc.from_utc_date(&entry.date), qty));
                        qty
                    }
                    Directive::Take(d) => {
                        let qty = qty.saturating_sub(d.amount);
                        quantities.push((Utc.from_utc_date(&entry.date), qty));
                        qty
                    }
                    Directive::Count(d) => {
                        counts.push((Utc.from_utc_date(&entry.date), d.amount));
                        qty
                    }
                    _ => qty,
                };
                (qty, max_qty.max(qty), quantities, counts)
            },
        );

        let mut chart = ChartBuilder::on(&root)
            .caption(part.part_number, ("Arial", 20).into_font())
            .margin(30)
            .x_label_area_size(20)
            .y_label_area_size(20)
            .build_ranged(beginning..today, 0..max_qty)?;

        // TODO: report errors
        chart
            .configure_mesh()
            .label_style(("Arial", 5).into_font())
            .x_label_formatter(&|date| date.format("--%m-%d").to_string())
            .draw()?;

        chart.draw_series(LineSeries::new(quantities, &RED))?;
        chart.draw_series(PointSeries::of_element(
            counts,
            1,
            ShapeStyle::from(&GREEN).filled(),
            &|coord, size, style| {
                EmptyElement::at(coord)
                    + Circle::new((0, 0), size, style)
                    + Text::new(
                        format!("{}, {}", coord.0.naive_utc(), coord.1),
                        (0, -5),
                        ("Arial", 5).into_font(),
                    )
            },
        ))?;
    }

    let svg_text = std::str::from_utf8(&buffer)?;
    Ok(div![El::from_html(svg_text)])
}

This code sample isn't really a minimum code sample reproducing the error. I plan on making one soon.

First of all, I would like to say thank you for such an amazing library! I really like your approach. Hope it will evolve to be a de-facto standard for Rust graphics.

The question is: how am I supposed to configure plotter to draw in an logarithmic scale? I am particularly interested in a logarithmic histograms.

We have one method
pub fn label_style<T: Into<TextStyle<'b>>>(&mut self, style: T) -> &mut Self
to change styles of both x/y labels.

Would be nice to have ability to change styles independently.

Now the default rasterizer supports stroke width for almost all the operations.

But circle is the last one that ignores the stroke width property.

We should resolve this.

Thank you for the crate!

How to configure steps X / Y axis steps to be more granular, e.g.:

https://github.com/38/plotters/blob/master/examples/stock.rs#L38

First step in X axis: 2019-03-13, last step 2019-04-24, how to force display all 30 dates as steps in this graph?

How can i set line width for LineSeries?

How to set:

1. General font style and font-size?
2. Custom font-size for axis labels?

• What is the feature ?

After working on #56 and #54 I think it would be nice to have some some reference benchmarks to measure if certain changes actually improve or degrade performance, esp. when iterating the CPU-only BitMapBackend.

• Why do you need the feature ?
• What is the use case ?

See above.

Hi, Thanks for updating the example. I tried it on my PC and get the following compilation error:

error[E0277]: `*mut u8` cannot be shared between threads safely
  --> c:\Localdata\extra\rust\38_plotters\src\drawing\backend_impl\canvas.rs:62:6
   |
62 | impl DrawingBackend for CanvasBackend {
   |      ^^^^^^^^^^^^^^ `*mut u8` cannot be shared between threads safely