ohlc-chart-simple v0.0.1131

ohlc-chart-simple

simple ohlc candlestick charts with volume profile for Node.js

Installation

npm i ohlc-chart-simple

Usage

var {drawChartForCandles,saveChartForCandles,
    generateRandomCandles, 
    //use these 2 funcs to print candles to console...
    printCandles, printCandlesColored} = require('ohlc-chart-simple');

var candles = [...];

//format of candles [
// {
//     open: 1.0,
//     high: 1.0,
//     low: 1.0,
//     close: 1.0,
//     date: "anything"
// } ...
// ]

candles = candles.map(function(candle){
    //candle.date is arbitrary string used to label current date in upper right corner
    //ex candle.date = moment.unix(candle.timestampUnix).format("YYYY-MM-DD HH:mm");

    //setting candle.title overwrites the graph title. nice for animations.
    //candle.title = "hey";

    //additional lines for indicators can be added by adding .indicators["NAME"], .indicators["NAME_color"], .indicators["NAME_thickness"]
    //in this example we add a thick blue line for candle midPts, and a thin pink line of candle lows-0.1%
    candle.indicators = {
        midPt: (candle.low+candle.high)/2.0,
        midPt_color: [0,0,255], //fields ending with "_color" specific color [default red]
        midPt_thickness: 1, //fields ending with "_thickness" specific line 'radius' [default 2]

        "0.1% lower": candle.low*0.999,
        "0.1% lower_color": [255,0,255], //pink
        "0.1% lower_thickness": 0 //0 gives single-pixel line
    }
    return candle;
});

//config optional; default params shown
var config = {
    w: 1024,
    h: 700,
    rects: [], //rectangles {minPrice,maxPrice,startIndex,endIndex,color,filled,thickness} -- example {minPrice: 140, maxPrice: 145, startIndex:5, endIndex: 15, color: [255,0,0], filled: true, thickness:0}
    rectsBelow: [], //same as rects but drawn BEHIND the bars, price lines, text, etc. 
    lines: [], //draw lines on the chart {startPrice, endPrice, startIndex, endIndex, color: [0,0,0], thickness:0}
    profileBucketsTotal: 32,
    profileBucketsWidth: 64, //set to zero to skip VP render 
    volumeBarsHeight: 32,
    bgColor: [255,255,255],

    //alternative to volume profile: arbitrary kernel density histogram
    //uncommenting these will replace VP with KDE graph of the same width
    // kdePrices: candles.map(c=>[c.low, 1]),
    // kdeBandwidthDollars: 0.00,
    // kdeBandwidthPercent: 1.00,
    // kdeIsGaussian: true, //false == kernel is triangular 
    
    skipDrawOhlcBars: false,
    skipDrawIndicators: false,
    skipDrawLegend: false,
    expandLegendText: true,
    expandTitle: true,
    expandPrice: true,
    skipDrawDate: false,
    skipDrawPrice: false,
    skipDrawPriceBars: false,
    title: "untitled",
    filename: "candlestick-chart.png",
    canvas: null, //reuse existing canvas 
    candlePaddingVerticalDollars: 0.01, //add vertical whitespace to candles, in dollars
}

saveChartForCandles(candles, config);
//var canvas = drawChartForCandles(candles, config); //get pixel canvas with image data from require('pixel-draw')

note: light blue bar is volume POC, light green bar is VWAP over the range of the chart

smaller example

simpler example

example including rectangle, line, KDE graph see test.js

See Also

• vwap-fast
• line-chart-simple