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Hello! As described in the title, my question is how I could input the parameter for a std::map structure in a roslaunch file, which is needed by a node. I use ros-indigo. Thanks in advance!
I guess the question is rather how to get some configuration from a launch file into the nodes, that you go on to store that information in an std::map just an extra.
You most probably want to use the parameter server which is available to you per default when you run ROS.
You can store name-value pairs on the server in a launch file with the <param> tag then you can access it in your node as described in the documentation.. In Brief:
ros::param::param<std::string>("default_param", default_param, "default_value");
Note that the parameter names are global, but you can set private parameters per node by putting the tag inside the <node> tag:
<node ...>
<param name="foo" .../>
</node>
Then you need to use "~foo" to access it.
PS: It is possible to store an entire map with a single name on the parameter server, but I know of no way to use that feature with launch files. You will need to specify a parameter for each map element.
PPS:
Also note the convenient <rosparam> tag that allows:
<rosparam>
my_parameter_1: 768
my_parameter_2: 480
</rosparam>
I figured it out, one can do it by using rosparam command in a ros launch file in this way:
<node pkg="xxx" name="yyy" type="ggg" output="screen">
<!-- without "~" in front of the parameter name -->
<rosparam param="name_map_structure">
x: 1
y: 2
z: 3
</rosparam>
</node>
Assume here that the private parameter name_map_structure is an instance of std::map<std::string, int>.
Hi, this is his original answer. Later I figured it out by myself and posted the answer here. "PS: It is possible to store an entire map with a single name on the parameter server, but I know of no way to use that feature with launch files. You will need to specify a parameter for each map element."
Asked: 2015-11-03 12:55:55 -0500
Seen: 2,145 times
Last updated: Nov 04 '15
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