subPixelOptimize: function(position, lineWidth) {
    if (lineWidth % 2 == 1) {
        //position += position == Math.ceil(position) ? 0.5 : 0;
        position = Math.floor(position) + 0.5;
    } else {
        position = Math.round(position);
    }
    return position;
}

var curCoord = categoryAxis.getCoordByIndex(dataIndex);
while (curCoord < xEnd) {
    if (curCoord <= x) {
        left = curCoord;
    }
    if (curCoord >= x) {
        break;
    }
    curCoord = categoryAxis.getCoordByIndex(++dataIndex);
    right = curCoord;
}