Plotr是一个基于PlotKit与MochiKit的轻量级Javascript制图库。Plotr依赖于prototype以及HTML Canvas。

Plotr 的使用相当简单，下面是Plotr的官方示例：

// Define a dataset.
var dataset = {
    'myFirstDataset': [[0, 1], [1, 1], [2, 1.414], [3, 1.73], [4, 2.56]],
    'mySecondDataset': [[0, 0.3], [1, 2.67], [2, 1.34], [3, 1.73], [4, 1.9]],
    'myThirdDataset': [[0, 0.46], [1, 1.45], [2, 2.5], [3, 1.2], [4, 2.4]],
    'myFourthDataset': [[0, .86], [1, 0.83], [2, 3], [3, 1.73], [4, 0.76]],
};
// Define options.
var options = {
    // Define a padding for the canvas node
    padding: {left: 30, right: 0, top: 10, bottom: 30},
    // Background color to render.
    backgroundColor: '#d8efb0',
    // Use the predefined blue colorscheme.
    colorScheme: 'grey',
    // Render a horizontal oriented barchart.
    barOrientation: 'vertical',
    // Set the labels.
    xTicks: [
        {v:0, label:'day 1'},
        {v:1, label:'day 2'},
        {v:2, label:'day 3'},
        {v:3, label:'day 4'}
    ]
};
// Instantiate a new BarCart.
var vertical = new Plotr.BarChart('bars1',options);
// Add a dataset to it.
vertical.addDataset(dataset);
// Render it.
vertical.render();

效果如下：