/uPlot

📈 A small, fast chart for time series, lines, areas, ohlc & bars

Primary LanguageJavaScriptMIT LicenseMIT

📈 μPlot

A small (< 30 KB min), fast chart for time series, lines, areas, ohlc & bars (MIT Licensed)

Introduction

μPlot is a fast, memory-efficient Canvas 2D-based chart for plotting time series, lines, areas, ohlc & bars; from a cold start it can create an interactive chart containing 150,000 data points in 135ms, scaling linearly at ~25,000 pts/ms. In addition to fast initial render, the zooming and cursor performance is by far the best of any similar charting lib; at < 30 KB, it's likely the smallest and fastest time series plotter that doesn't make use of context-limited WebGL shaders or WASM, both of which have much higher startup cost and code size.

166,650 point bench: https://leeoniya.github.io/uPlot/bench/uPlot.html

However, if you're looking for true real-time 60fps performance with massive datasets, uPlot can only get you so far. WebGL should still be the tool of choice for applications like realtime signal or waveform visualizations: Try danchitnis/webgl-plot, huww98/TimeChart, epezent/implot.

uPlot Chart

Features

Non-Features

In order to stay lean, fast and focused the following features will not be added:

  • No data parsing, aggregation, summation or statistical processing - just do it in advance. e.g. https://simplestatistics.org/, https://www.papaparse.com/
  • No transitions or animations - they're always pure distractions.
  • No collision avoidance for axis tick labels, so may require manual tweaking of spacing metrics if label customization signficiantly increases default label widths.
  • No stacked series or line smoothing. See links for how these are each terrible at actually communicating information. While neither will be part of the core, uPlot's API makes it easy to implement both: stacked-series, line-smoothing.
  • No built-in drag scrolling/panning. Maintaining good perf with huge datasets would require a lot of extra code & multiple <canvas> elements to avoid continuous redraw and rescaling on each dragged pixel. If you have fewer than tens of thousands of datapoints, you can use uPlot's API to implement smooth zooming or panning. e.g. zoom-wheel, zoom-touch. Pagination of data also works well.

Documentation (WIP)

The docs are a perpetual work in progress, it seems. Start with /docs/README.md for a conceptual overview. The full API is further documented via comments in /dist/uPlot.d.ts. Additionally, an ever-expanding collection of runnable /demos covers the vast majority of uPlot's API.

Performance

Benchmarks done on a ThinkPad T480S:

  • Date: 2020-09-18
  • Windows 10 x64, Chrome 85.0.4183.102 (Official Build) (64-bit)
  • Core i5-8350U @ 1.70GHz, 8GB RAM
  • Intel HD 620 GPU, 2560x1440 res

uPlot Performance

Full size: https://leeoniya.github.io/uPlot/demos/multi-bars.html

Raw data: https://github.com/leeoniya/uPlot/blob/master/bench/results.json

| lib            | size    | done    | js,rend,paint,sys | heap peak,final | interact (10s)      |
| -------------- | ------- | ------- | ----------------- | --------------- | ------------------- |
| uPlot          |   28 KB |   65 ms |   99   5   1   67 |  15 MB   3 MB   |  198  371  129  237 |
| Chart.js-next  |  229 KB |  235 ms |  289   2   1   95 |  32 MB  20 MB   | 3604   34   46 6125 |
| LightningChart |  931 KB |  --- ms |  356   3   1   70 |  26 MB  20 MB   | 9114   65   55  272 |
| dygraphs       |  125 KB |  185 ms |  260   4   2  171 |  93 MB  48 MB   | 2294  241  114  404 |
| CanvasJS       |  479 KB |  323 ms |  378   5   1   93 |  40 MB  25 MB   | 2173  457  119  397 |
| Flot           |  494 KB |  334 ms |  202   7   2  283 |  24 MB  19 MB   | ---                 |
| dvxcharts      |  369 KB |  326 ms |  585  34   2   62 |  62 MB  26 MB   | 1394  717  204  270 |
| Highcharts     |  384 KB |  --- ms |  748   9   2   75 |  49 MB  21 MB   | 2012  725  217  317 |
| Chart.js       |  245 KB |  654 ms |  718   4   2  164 | 101 MB  85 MB   | 5550    5    7 4020 |
| Plotly.js      | 3400 KB |  465 ms |  828   7   1   83 |  50 MB  28 MB   | 1507  229   53  177 |
| ECharts        |  785 KB |  --- ms |  718   6   7 1120 | 116 MB  77 MB   | 2016   70   25 7856 |
| ApexCharts     |  460 KB |  --- ms | 2137  28   3   73 | 170 MB  97 MB   | 2030  220   28  122 |
| ZingChart      |  857 KB | 2535 ms | 2711   7   1   66 | 143 MB  85 MB   | ---                 |
| amCharts       | 1200 KB | 5825 ms | 7509  47  13   78 | 256 MB 256 MB   | 6932 1288  282  512 |
  • size includes the lib itself plus any dependencies required to render the benchmark, e.g. Moment, jQuery, etc.
  • Flot does not make available any minified assets and all their examples use the uncompressed sources; they also use an uncompressed version of jQuery :/

TODO (all of these use SVG, so performance should be similar to Highcharts):

  • Chartist.js
  • d3-based
    • C3.js
    • dc.js
    • MetricsGraphics
    • rickshaw

Acknowledgements