Ask Your Question

Kent Williams's profile - activity

2017-01-06 15:41:14 -0500 received badge  Famous Question (source)
2014-11-27 00:40:27 -0500 received badge  Famous Question (source)
2014-11-23 14:22:43 -0500 received badge  Notable Question (source)
2014-08-16 10:49:47 -0500 received badge  Popular Question (source)
2014-08-12 11:06:04 -0500 received badge  Notable Question (source)
2014-08-05 14:17:10 -0500 answered a question Cannot Visualize laser scan publisher tutorial

Its because the range values increasingly get really large really quickly.

I just set ranges[i] = 2; and I can see the points fine now.

2014-08-05 12:55:46 -0500 asked a question Cannot Visualize laser scan publisher tutorial

Hello All,

I'm not able to visualize the scan topic in rviz when running this tutorial node.

I have the fixed frame set to laser_frame and I can see the messages being received. Is there something I need change in order to see the range points in rviz?


2014-08-01 14:58:02 -0500 received badge  Popular Question (source)
2014-08-01 14:49:06 -0500 commented answer LaserScan msg ranges.resize() - Arduino

Thanks for the response Stefan! So if the vector is of type float*, should I be declaring and initializing my ranges variable like so: float *ranges = new float[num_readings]; and then assigning the ranges to the msg type like so: scan_msg.ranges = ranges; This seems to be restricting the ros serial python node from connecting.... so something is off.

2014-07-31 21:31:41 -0500 asked a question LaserScan msg ranges.resize() - Arduino

Hello All,

I am getting the following error when compiling my rosserial_arduino code for sampling and sending a LaserScan msg.

This code works just fine in a standard ros c++ node. Does this member not exist? Am I not accessing it correctly? Thanks!

Compilation Error:

error: request for member ‘resize’ in ‘scan_msg.sensor_msgs::LaserScan::ranges’, which is of non-class type ‘float’*

Code in Question:

unsigned int node_count = 10;


2012-12-14 15:47:07 -0500 received badge  Enthusiast
2012-03-05 15:42:13 -0500 received badge  Enlightened (source)
2012-03-05 15:42:13 -0500 received badge  Good Answer (source)
2012-02-06 00:12:11 -0500 received badge  Nice Answer (source)
2012-02-05 15:09:42 -0500 commented answer Is $ROS_PACKAGE_PATH after source install okay?
I believe it is because of the flexibility that rosinstall provides. If a package can be installed via rosinstall, it's installation directory can be outside of the main ros dir and sometimes really should be since it's often used for building dev source. Then it's auto appended to the package path.
2012-02-05 14:22:18 -0500 received badge  Editor (source)
2012-02-05 14:21:21 -0500 answered a question Is $ROS_PACKAGE_PATH after source install okay?

That is the expected outcome, but you installed in a directory owned by root. I would suggest installing in your user home directory. rosinstall auto generates this based on what it installed. If you are going to build packages yourself, be sure to append to the $ROS_PACKAGE_PATH by following the instructions here

2012-02-04 19:29:06 -0500 received badge  Nice Answer (source)
2012-02-04 11:59:37 -0500 received badge  Teacher (source)
2012-02-04 11:52:50 -0500 answered a question ros-electric-desktop-full not found

You will have to build from source, see

2012-01-20 15:41:48 -0500 received badge  Supporter (source)