How to modify the number of rays of a real LiDAR machine?

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Hello, I'm working with ROS kinetic of Ubuntu 16.04.

I'm using Hokuyo's LiDAR of the UBG-04LX-F01 model, and also being suffered from some troubles..

Would it be possible to modify the number of rays from the real LiDAR machine?

I always do this command before using it,

$ roslauch urg_node urg_lidar.launch

but urg_lidar.launch seems that it doesn't include any arguments concerning the number of rays.

The LiDAR I'm using currently makes 726 rays, and I'd like to change it to 720.

Would you happen to give me help?

Best Regard :)