Problem with publishing Twist message from a node

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I wrote a piece of C++ code which should publish twist message and make a fake turtlebot start moving in Rviz. But after running it, the robot had no reaction.Here is my code.

#define PI 3.14
#include "ros/ros.h"
#include "geometry_msgs/Twist.h"

int main(int argc, char **argv)
{
ros::init(argc, argv, "test");
ros::NodeHandle n;
ros::Publisher cmd_vel_pub=
    n.advertise<geometry_msgs::Twist>("cmd_vel",5);
    int rate=50;
ros::Rate loop_rate(rate);

double linear_speed=0.2;
double goal_distance=1.0;
double linear_duration=goal_distance/linear_speed;
double angular_speed=1.0;
double goal_angle=PI;
double angular_duration=goal_angel/angular_speed;
geometry_msgs::Twist twist_msg;
twist_msg.linear.x=twist_msg.linear.y=twist_msg.linear.z=0;
twist_msg.angular.x=twist_msg.angular.y=twist_msg.angular.z=0;

while(ros::ok())
{
    twist_msg.linear.x=linear_speed;
    int ticks=static_cast<int>(linear_duration*rate);
    for(int j=0;j<ticks;j++)
    {
        cmd_vel_pub.publish(twist_msg);
        loop_rate.sleep();
    }

    twist_msg.linear.x=0;
    cmd_vel_pub.publish(twist_msg);
    ros::Duration(1).sleep();

    twist_msg.angular.z=angular_speed;
    ticks=static_cast<int>(goal_angle*rate);
    for(int j=0;j<ticks;j++)
    {
        cmd_vel_pub.publish(twist_msg);
        loop_rate.sleep();
    }

    twist_msg.angular.z=0;
    cmd_vel_pub.publish(twist_msg);
    ros::Duration(1).sleep();

}

twist_msg.linear.x=0;
twist_msg.angular.z=0;
cmd_vel_pub.publish(twist_msg);
ros::Duration(1).sleep();

return 0;

}

I also add the following code in CMakeList.txt

include_directories(include ${catkin_INCLUDE_DIRS})
add_executable(test src/talker.cpp)
target_link_libraries(test ${catkin_LIBRARIES})

Add this to package.xml

<build_depend>geometry_msgs</build_depend>
<run_depend>geometry_msgs</run_depend>