text: #!/usr/bin/env python3
  import rospy
  from visualization_msgs.msg import Marker
  
  def talker():
      pub_g = rospy.Publisher('marker', Marker, queue_size=10)
  
      rospy.init_node('sim_', anonymous=True)
      rate = rospy.Rate(10) # 10hz
      marker = Marker()
  
      marker.header.frame_id = "world"
      marker.header.stamp = rospy.Time.now()
  
      # set shape, Arrow: 0; Cube: 1 ; Sphere: 2 ; Cylinder: 3
      marker.type = 2
      marker.id = 0
  
      # Set the scale of the marker
      marker.scale.x = 0.2
      marker.scale.y = 0.2
      marker.scale.z = 0.2
  
      # Set the color
      marker.color.r = 0.0
      marker.color.g = 1.0
      marker.color.b = 0.0
      marker.color.a = 1.0
  
      # Set the pose of the marker
      marker.pose.position.x = 5.25
      marker.pose.position.y = 8.75
      marker.pose.position.z = 0
      marker.pose.orientation.x = 0.0
      marker.pose.orientation.y = 0.0
      marker.pose.orientation.z = 0.0
      marker.pose.orientation.w = 1.0
      while not rospy.is_shutdown():
          pub_g.publish(marker)
          rate.sleep()
  
  if __name__ == '__main__':
      try:
          talker()
      except rospy.ROSInterruptException:
          pass