# My node doesn't publish to the topic cmd_vel

I created a node in order to move the robot and rotate it but it seems that the node doesn't publish to Twist can anyone help ?

## this is my code

```
#!/usr/bin/env python
import rospy
from geometry_msgs.msg import Twist
PI = 3.1415926535897
class movement :
def __init__(self):
rospy.init_node('move_robot_node', anonymous=False)
self.pub_move = rospy.Publisher("/marvin/diff_drive_controller/cmd_vel",Twist,queue_size=10)
def move_forward(self):
print "hi"
move =Twist()
move.linear.x=1
move.angular.z=0.0
self.pub_move.publish(move)
print Twist()
def move_backward(self):
move =Twist()
move.linear.x=-1
move.angular.z=0.0
self.pub_move.publish(move)
def stop(self):
move =Twist()
move.linear.x=0
move.angular.z=0.0
self.pub_move.publish(move)
def rotate_right(self):
move =Twist()
# Receiveing the user's input
print("Let's rotate your robot")
speed = 100
angle = 90
clockwise = True #True or false
#Converting from angles to radians
angular_speed = speed*2*PI/360
relative_angle = angle*2*PI/360
#We wont use linear components
move.linear.x=0
move.linear.y=0
move.linear.z=0
move.angular.x = 0
move.angular.y = 0
# Checking if our movement is CW or CCW
if clockwise:
move.angular.z = -abs(angular_speed)
print move.angular.z
else:
move.angular.z = abs(angular_speed)
# Setting the current time for distance calculus
t0 = rospy.Time.now().to_sec()
current_angle = 0
while(current_angle < relative_angle):
self.pub_move.publish(move)
t1 = rospy.Time.now().to_sec()
current_angle = angular_speed*(t1-t0)
#Forcing our robot to stop
move.angular.z = 0
self.pub_move.publish(move)
rospy.spin()
while not rospy.is_shutdown() :
mov = movement()
mov.move_forward()
rospy.spin()
```