Sparklines react component

gistfile1.jsx

class Sparkline extends React.Component {
            constructor(props) {
              super(props);
              console.log(props)
              this.state = {
                values: props.values,
                width: props.width,
                height: props.height,
              }
            }

            componentWillReceiveProps(nextProps) {
              this.setState({
                values: nextProps.values
              });
            }

            render() {
              var values = this.state.values || [0];
              var limits = [Math.max(0, Math.min.apply(this, values) - 1), Math.max.apply(this, values) + 1];
              var scale = Math.pow(10, Math.floor(Math.log10(limits[1] - limits[0])));
              var domain = [Math.floor(limits[0] / scale) * scale, Math.ceil(limits[1] / scale) * scale];
              var range = [this.state.height, 0];
              var step = this.state.width / Math.max(values.length - 1, 1)
              var x = function(dx) { return dx * step; };
              var y = function(dy) { return ((dy - domain[0]) / (domain[1] - domain[0]) * (range[1] - range[0])) + range[0]; };
              var path = values.map(function (v, i) { return "L" + x(i) + "," + y(v); }).join()
              var strokepath = "M" + path.substring(1);
              var fillpath = "M0," + range[0] + path + "L" + this.state.width + "," + range[0] + "L0," + range[0]
              var lastval = values.slice(-1)[0];
              return (
                <svg id="sparkline" width={this.state.width} height={this.state.height}>
                  <rect width={this.state.width} height={this.state.height} fill={'#EEE'}/>
                  <path className="sparkfill" d={fillpath}/>
                  <path className="sparkstroke" d={strokepath}/>
                  <text x={0} y={range[0]} fontFamily="Verdana" fontSize="8">{domain[0]}</text>
                  <text x={0} y={range[1]} fontFamily="Verdana" fontSize="8">{domain[1]}</text>
                  <text x={this.state.width} y={y(lastval)} fontFamily="Verdana" fontSize="8">{lastval}</text>
                </svg>
              )
            }
          }