# simple fake odometry publisher

I want to test rtabmap. I have d435 camera, but I dont have wheels yet.

So, I want to use simple fake odometry publisher, to publish zeros, to pretend that robot is not moving.

I tried this code, but I am not sure that it is working correctly, because I have got freezes of mapCloud. And I am afraid it is somehow related to this code.

```
#!/usr/bin/env python
import math
from math import sin, cos, pi
import rospy
import tf
from nav_msgs.msg import Odometry
from geometry_msgs.msg import Point, Pose, Quaternion, Twist, Vector3
rospy.init_node('odometry_publisher')
odom_pub = rospy.Publisher("odom", Odometry, queue_size=50)
odom_broadcaster = tf.TransformBroadcaster()
x = 0.0
y = 0.0
th = 0.0
vx = 0.0
vy = 0.0
vth = 0.0
current_time = rospy.Time.now()
last_time = rospy.Time.now()
r = rospy.Rate(50.0)
while not rospy.is_shutdown():
current_time = rospy.Time.now()
# compute odometry in a typical way given the velocities of the robot
dt = (current_time - last_time).to_sec()
delta_x = (vx * cos(th) - vy * sin(th)) * dt
delta_y = (vx * sin(th) + vy * cos(th)) * dt
delta_th = vth * dt
x += delta_x
y += delta_y
th += delta_th
# since all odometry is 6DOF we'll need a quaternion created from yaw
odom_quat = tf.transformations.quaternion_from_euler(0, 0, th)
# first, we'll publish the transform over tf
odom_broadcaster.sendTransform( (x, y, 0.), odom_quat, current_time, "base_link", "odom" )
# next, we'll publish the odometry message over ROS
odom = Odometry()
odom.header.stamp = current_time
odom.header.frame_id = "odom"
# set the position
odom.pose.pose = Pose(Point(x, y, 0.), Quaternion(*odom_quat))
# set the velocity
odom.child_frame_id = "base_link"
odom.twist.twist = Twist(Vector3(vx, vy, 0), Vector3(0, 0, vth))
# publish the message
odom_pub.publish(odom)
last_time = current_time
r.sleep()
```

Is this code correct to publish zeros in odometry?