Problem in Map buildiing using Gmapping

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I have created a bag file using the attached code of bagconvert.py, The code is pasted, #!/usr/bin/env python import rospy import rosbag from sensor_msgs.msg import LaserScan from math import pi from tf2_msgs.msg import TFMessage from geometry_msgs.msg import TransformStamped import tf

def make_tf_msg(x, y, theta, t): trans = TransformStamped() trans.header.stamp = t trans.header.frame_id = '/odom' trans.child_frame_id = '/laser' trans.transform.translation.x = x trans.transform.translation.y = y q = tf.transformations.quaternion_from_euler(0, 0, theta) trans.transform.rotation.x = q[0] trans.transform.rotation.y = q[1] trans.transform.rotation.z = q[2] trans.transform.rotation.w = q[3]

msg = TFMessage()
msg.transforms.append(trans)
return msg

with open('intel.clf') as dataset: with rosbag.Bag('intel.bag', 'w') as bag: for line in dataset.readlines(): line = line.strip() tokens = line.split(' ') if len(tokens) <= 2: continue if tokens[0] == 'FLASER': msg = LaserScan() num_scans = int(tokens[1])

            if num_scans != 180 or len(tokens) < num_scans + 9:
                rospy.logwarn("unsupported scan format")
                continue

            msg.header.frame_id = 'laser'
            t = rospy.Time(float(tokens[(num_scans + 8)]))
            msg.header.stamp = t
            msg.angle_min = -90.0 / 180.0 * pi
            msg.angle_max = 90.0 / 180.0 * pi
            msg.angle_increment = pi / num_scans
            msg.time_increment = 0.2 / 360.0
            msg.scan_time = 0.2
            msg.range_min = 0.001
            msg.range_max = 50.0
            msg.ranges = [float(r) for r in tokens[2:(num_scans + 2)]]

            bag.write('laser', msg, t)

            odom_x, odom_y, odom_theta = [float(r) for r in tokens[(num_scans + 2):(num_scans + 5)]]
            tf_msg = make_tf_msg(odom_x, odom_y, odom_theta, t)
            bag.write('tf', tf_msg, t)

        elif tokens[0] == 'ODOM':
            odom_x, odom_y, odom_theta = [float(t) for t in tokens[1:4]]
            t = rospy.Time(float(tokens[7]))
            tf_msg = make_tf_msg(odom_x, odom_y, odom_theta, t)
    bag.write('tf', tf_msg, t)

Now a file called intel.bag is created. now I am following the tutorial of building a map from logged data, roscore rosparam set use_sim_time true rosrun gmapping slam_gmapping scan:=laser rosbag play intel.bag After this in the Rviz window no map is built, and in the gmapping terminal an error message is shown "[ WARN] [1478603677.898065363]: Failed to compute laser pose, aborting initialization ("base_link" passed to lookupTransform argument target_frame does not exist. )". Please provide a solution.