khansaadbinhasan's profile - activity

@thimaya It has been a long time since I asked that question. From what I remember, I had made my desktop into a workspa

@thimaya It has been a long time since I asked that question. From what I remember, I had made my desktop into a workspa

I am trying to follow along this tutorial: http://wiki.ros.org/cv_bridge/Tutoria...

I am getting this error while running the above program:

from cv_bridge.boost.cv_bridge_boost import getCvType ImportError: dynamic module does not define module export function (PyInit_cv_bridge_boost)

I am using multiple versions of python, the one getting used seems to be: /opt/ros/melodic/lib/python2.7/ since it is in the traceback: /opt/ros/melodic/lib/python2.7/dist-packages/cv_bridge/core.py

echo $PYTHONPATH gives /home/kringata/catkin_ws/devel/lib/python2.7/dist-packages:/opt/ros/melodic/lib/python2.7/dist-packages

I am using ROS Melodic on Ubuntu18.04

This seems to be a python problem., I was able to use cv_bridge to convert cv2 image to ROS message but wasn't able to d

Unable to use opencv with ROS I am trying to follow along this tutorial: http://wiki.ros.org/cv_bridge/Tutorials/Convert

I am trying to build a workspace that is stored in: /home/usr/Desktop/ROS/workspace/, the workspace directory is clean and does not contain any hidden files hence .catkin_tools is not present. It only contains one directory src. I have tried catkin init with empty src directory and by putting a package in src. Here is the output:

Catkin workspace `/home/usr/Desktop` is already initialized. No action taken.
-----------------------------------------------------------
Profile:                     alternate
Extending:        [explicit] /opt/ros/melodic
Workspace:                   /home/usr/Desktop
-----------------------------------------------------------
Build Space:       [missing] /home/usr/Desktop/build
Devel Space:       [missing] /home/usr/Desktop/devel
Install Space:      [unused] /home/usr/Desktop/install
Log Space:         [missing] /home/usr/Desktop/logs
Source Space:      [missing] /home/usr/Desktop/src
DESTDIR:            [unused] None
-----------------------------------------------------------
Devel Space Layout:          linked
Install Space Layout:        None
-----------------------------------------------------------
Additional CMake Args:       None
Additional Make Args:        None
Additional catkin Make Args: None
Internal Make Job Server:    True
Cache Job Environments:      False
-----------------------------------------------------------
Whitelisted Packages:        None
Blacklisted Packages:        None
-----------------------------------------------------------


-----------------------------------------------------------
WARNING: Source space `/home/usr/Desktop/src` does
not yet exist.
-----------------------------------------------------------

What I don't understand is why is catkin looking for workspace in /home/usr/Desktop and not the current directory? The same package is easily built with catkin_make though and I am able to run all the nodes. Also If I put src in /home/usr/Desktop I am able to build successfully.

I am using ROS Melodic on Ubuntu 18.04. I am not sure about the catkin tools version but i installed it from here: https://jbohren-ct.readthedocs.io/en/...

Thanks for the answer. It worked, I didn't knew i had it on my desktop, but why should that matter? I can have multiple

[build] Error: Unable to find source space `/home/usr/Desktop/src` I am trying to build a workspace that is stored in: /

[build] Error: Unable to find source space `/home/usr/Desktop/src` I am trying to build a workspace that is stored in: /

I am working with some rosbags, rosbag info shows that there are some dynamically reconfigurable parameters which i want to configure but these parameters are not shown when i use rosparam list. In the documentation it was mentioned that rosbags record data on the topics mentioned with rosbag record, so my question is-

Do rosbags record data other than the data they get by subscribing on the topics?

Specific information- I am using Ubuntu 16.04, ROS kinetic, the rosbags were taken from Velodyne VLP-16 LIDAR, I am not sure about the drivers/packages used with VLP-16 since i was only provided with the bags.

How Cartographer publishes Map to base_link transform? I am using google's cartographer to build a map, but I am unable

I am trying to launch two different nodes from two different workspaces from the same terminal. But once I source my terminal with one of the workspaces, I am not able to use the other packages since the other workspace directory is not sourced anymore.

Even though I saw this answer, it doesn't work for me, maybe since I am using catkin build. Also, I don't want to keep deleting my build, devel spaces.

I have noticed that it may be possible to assign priority of search to ros as two setup.zsh are already sourced source /opt/ros/kinetic/setup.zsh and one of my workspaces. ROS seems to be assigning priority to these while searching for packages.

Can anyone please explain me how sourcing of setup.zsh files work? And how can I find a workaround to my problem or preferably use the method used by ROS itself

How to source multiple workspaces from the same terminal? I am trying to launch two different nodes from two different w

Generate Maps from .world files I am working with navigation stack, I need a map for it. I am running a simulation in ga

Generate Maps from .world files I am working with navigation stack, I need a map for it. I am running a simulation in ga

I want to dynamically reconfigure a parameter as mentioned in this question, I do not want to run the robot for it, instead I want some way to get data from the robot and then work on the dynamic reconfiguration part. I need something similar to rosbags but not rosbags since they use topics to record data as mentioned in the answer

EDIT1: adding more information

I am working with a Velodyne VLP-16 LIDAR, since its a very costly sensor I have to work with bag files, actually its a 16-channel LIDAR and I want to reconfigure its disk value from the default 8 to 2, Here is the rosbag info:

path:        third_run.bag
  version:     2.0
  duration:    1:02s (62s)
  start:       Dec 05 2018 12:34:13.22 (1543993453.22)
  end:         Dec 05 2018 12:35:15.56 (1543993515.56)
  size:        469.3 MB
  messages:    2294
  compression: none [571/571 chunks]
  types:       bond/Status                           
               diagnostic_msgs/DiagnosticArray      
               dynamic_reconfigure/Config           
               dynamic_reconfigure/ConfigDescription
               sensor_msgs/LaserScan                
               sensor_msgs/PointCloud2              
               velodyne_msgs/VelodyneScan           
  topics:      /diagnostics                                                  62 msgs    : diagnostic_msgs/DiagnosticArray      
               /scan                                                        617 msgs    : sensor_msgs/LaserScan                
               /velodyne_nodelet_manager/bond                               372 msgs    : bond/Status                          
               /velodyne_nodelet_manager_cloud/parameter_descriptions         1 msg     : dynamic_reconfigure/ConfigDescription
               /velodyne_nodelet_manager_cloud/parameter_updates              1 msg     : dynamic_reconfigure/Config           
               /velodyne_nodelet_manager_driver/parameter_descriptions        1 msg     : dynamic_reconfigure/ConfigDescription
               /velodyne_nodelet_manager_driver/parameter_updates             1 msg     : dynamic_reconfigure/Config           
               /velodyne_nodelet_manager_laserscan/parameter_descriptions     1 msg     : dynamic_reconfigure/ConfigDescription
               /velodyne_nodelet_manager_laserscan/parameter_updates          1 msg     : dynamic_reconfigure/Config           
               /velodyne_packets                                            618 msgs    : velodyne_msgs/VelodyneScan           
               /velodyne_points                                             619 msgs    : sensor_msgs/PointCloud2

As you can see, it has dynamically reconfigurable parameters, which I want to configure through code so I can get the data I want, but as I mentioned above, it is not possible with bag files. So, I am looking for something similar to bag files where I have access to param server

EDIT2: Replaced image with text