public PointValue set(float x, float y) {
        this.x = x;
        this.y = y;
        this.originX = x;
        this.originY = y;
        this.diffX = 0;
        this.diffY = 0;
        return this;
    }
Single point coordinates, used for LineChartData.
hellocharts-library/src/lecho/lib/hellocharts/model/PointValue.java