catchart

catchart

(pronounced ca-chart)

Pipe something from command line to a chart in the browser

uses chart.js for, ahem, charting...

command line

npm i -g catchart

catchart --help

simple y over t

echo 1\n2\n3\n | catchart

custom label / value

echo sunday,1,2,3\nmonday,4,5,6\ntuesday,7,8,9\n | catchart --labelSource=row

multiple data sets over time

echo 1,2,3\n4,5,6\n-1,-2,-3\n | catchart

other chart types, custom title

echo 1,2,3\n4,5,6\n-1,-2,-3 | catchart --title=catchart --chartType=bar

chart types: line, bar, radar, pie, doughnut, scatter, polar, bubble

JSON input works too!

echo "{ \"data\": 1 }"\n"{ \"data\": 2, \"label\": \"foo\" }"\n | catchart

api

catchart cli in it's simplest form, looks very much like this:

const { pipeline } = require('stream')
const catchart = require('./index')
const split = require('split')

pipeline(process.stdin, split(), catchart(), err => err ? console.error(err) : undefined)

features

• support most of chart.js chart types
• support json and simple array input formats
• specify configuration through environment variables, files or cli parameters (see rc module and commander module for further information)
• fill the area under the line, also supports patterns.
• restrict the amount of displayed data using --windowSize. Catchart will dump data that falls outside of the window.
• align data to a left or right Y axis using configuration or automatically:
  • --yLeft=[0, 1, 2] and --yRight=[3, 4] will make series 0, 1 and 2 be on the left and 3,4 on the right. When using this config, all the series indices must be specified. With arrays the first item is the X value, if your input array is [1,2,3,4,5], yLeft=0,1 and yRight=3,4 will put 2 and 3 on the left Y axis and 3,4 on the right Y axis for X=1
  • Auto align Y axis: a somewhat feeble/experimental attempt at grouping series with similar magnitude on the left and right Y axes. --disableAutoAlignYAxis to disable

dev

• clone this repo
• hack
• npm run build_client; node emitter <csv | singlecsv | json> | node catchart`
• also node emitter.js csv | node catchart.js --yLeft=[0,1] --yRight=[2,3]
• send a PR :)

TODOS

• refactor code, especially server
• write tests (right now using emitter.js to test manually)

license

MIT © Yaniv Kessler

Changelog

[3.2.7] - 2022-10-15

Changed

• remove own stream-slicer module in favor of dominic's split module