Firstly, You have to include map of your environment in png format in your launch file. I assume that you are launching this file for SBPL planner : launch / move_base_sbpl_fake_localization_2.5cm.launch
If you open this file, there is a node which include map and publishes map to the /map topic.
<node name="map_server" pkg="map_server" type="map_server" args="$(find sbpl_lattice_planner)/worlds/willow.pgm 0.025"/>
remove willlow.pgm and instead give your map address. also remove next <node> line its for inbuilt simulator stage.
so, Once try to run it on your robot and see the /map data on rviz,
( roslaunch turtlebot_rviz_launchers view_navigation.launch ) is the best and simplest way to do it
Here you can give 2D navigation goal by manually clicking on the 2D map.
If you want to give goal position from terminal or code, you can modify the value of topic /move_base/simple_navigation_goal
(But, as you are trying to compare navigation i dont think that you would be bothered about exact same goal for both the planner. If you want exactly same goal then you should publish nav_goal to the above topic.)
NOTE: If you re-launch the map-server, it might not give same coordinate value for same point, i.e, ( point (0,0) might become point (2,2) in next iteration) So, consider that, For that i suggest you launch a separate file for /map and just relaunch the planners.
Hope this helped,
Sudeep
