How to convert a given point using your code ?

[ktiwari9]

Hi there,
I am quite new to ROS and I have been going crazy over TF. So my situation is this,
I have a node that gives me the global goal in /map frame from gazebo like this:
goal_pose_pub_= n_.advertise<geometry_msgs::PointStamped>("/global_goal", 10);

And in my A* Node, I have a callback
void AStar::goalCallback(const geometry_msgs::PointStamped::ConstPtr& goal_msg)

but the goal_msg currently contains the /map frame goal so needs to be transformed to /odom frame. So how can I use your code to transform the /global goal in the correct frame co-ordinates ?