global_planner changing parameters

edit

Hi folks,

I'd like to change the following parameters in the global_planner hydro-devel package to false to use the A* algorithme:

~<name>/use_dijkstra (bool, default: true)
If true, use dijkstra's algorithm. Otherwise, A*.

But I can't find the file in which I must make changes !!

EDIT:

File: move_base.launch.xml:

<!-- 
    ROS navigation stack with velocity smoother and safety (reactive) controller
-->
<launch>
  <include file="$(find turtlebot_navigation)/launch/includes/velocity_smoother.launch.xml"/>
  <include file="$(find turtlebot_navigation)/launch/includes/safety_controller.launch.xml"/>
  <arg name="odom_topic" default="odom" />
  <node pkg="move_base" type="move_base" respawn="false" name="move_base" output="screen">
  <param name="base_global_planner" value="global_planner/GlobalPlanner" />              
    <rosparam file="$(find turtlebot_navigation)/param/costmap_common_params.yaml" command="load" ns="global_costmap" />
    <rosparam file="$(find turtlebot_navigation)/param/costmap_common_params.yaml" command="load" ns="local_costmap" />
    <rosparam file="$(find turtlebot_navigation)/param/local_costmap_params.yaml" command="load" />
    <rosparam file="$(find turtlebot_navigation)/param/global_costmap_params.yaml" command="load" />
    <rosparam file="$(find turtlebot_navigation)/param/base_local_planner_params.yaml" command="load" />
    <rosparam file="$(find turtlebot_navigation)/param/move_base_params.yaml" command="load" />
    <remap from="cmd_vel" to="navigation_velocity_smoother/raw_cmd_vel"/>
    <remap from="odom" to="$(arg odom_topic)"/>
  </node>
</launch>

There's no Planner.yaml or global_planner.yaml that contains the parameter that I'd like to change !

Can someone help me please.

Regards.