Private Parameters in a sub namespace

edit

Hello,

I have a ROS node that essentially does this:

      ros::NodeHandle nh("~");
      ros::NodeHandle node_handle(nh, "derp"),
      node_handle.param<double>("rate", rate, 10.0);

Which means that the private parameter "rate" is pushed down into a namespace like so: derp/rate

I want to run aforementioned node from the command line and set this private parameter, but I do get errors. If the parameter were not in a sub namespace i could just launch the node by

rosrun mypack mynode _rate:=100

Running the node via rosrun mypack mynode derp/_rate:=100

Fails with a graph error. How can I set this private parameter via commandline?

Thanks!

Edit: running this with a launch file like so works:

<node name="mynode" pkg="mypack" type="mynode" output="screen"">
    <param name="derp/rate" value="100.0" />
</node>

But I do need to set this parameter via commandline.