Need help with find error in this urdf

edit

Hi, I am learning the tutorial about urdf. I am at the exercise 8 now. The error I have when run the launch file is:

[ERROR] [1478674779.727709696]: length [${bodylen}] is not a valid float
[ERROR] [1478674779.727814955]: Could not parse visual element for Link [base_link]
[ERROR] [1478674779.727917245]: radius [${width}] is not a valid float: bad lexical cast: source type value could not be interpreted as target
[ERROR] [1478674779.727969693]: Could not parse visual element for Link [head]

.....

I will include here to the code from start to base_link. Please help me point out the issue. I cannot find out what is wrong.

   <?xml version="1.0"?>
    <robot name="macroed" xmlns:xacro="http://ros.org/wiki/xacro">
    <!-- Convert to xacro-->
    <robot xmlns:sensor="http://playerstage.sourceforge.net/gazebo/xmlschema/#sensor"
              xmlns:controller="http://playerstage.sourceforge.net/gazebo/xmlschema/#controller"
              xmlns:interface="http://playerstage.sourceforge.net/gazebo/xmlschema/#interface"
              xmlns:xacro="http://playerstage.sourceforge.net/gazebo/xmlschema/#interface" name="macroed">

        ...

Edit 1: I found the problem. I missed the 4 rows below the link but I got a new error and I don't understand what it is:

...
process[rviz-4]: started with pid [7571]
[ERROR] [1478753950.661833770]: Error reading end tag.
[robot_state_publisher-3] process has died [pid 7563, exit code -11, cmd /opt/ros/indigo/lib/robot_state_publisher/state_publisher __name:=robot_state_publisher __log:=/home/ubuntu/.ros/log/6a4eafd8-a702-11e6-98d1-00044b581868/robot_state_publisher-3.log].
log file: /home/ubuntu/.ros/log/6a4eafd8-a702-11e6-98d1-00044b581868/robot_state_publisher-3*.log
Traceback (most recent call last):
  File "/opt/ros/indigo/lib/joint_state_publisher/joint_state_publisher", line 343, in <module>
    jsp = JointStatePublisher()
  File "/opt/ros/indigo/lib/joint_state_publisher/joint_state_publisher", line 26, in __init__
    robot = xml.dom.minidom.parseString(description).getElementsByTagName('robot')[0]
  File "/usr/lib/python2.7/xml/dom/minidom.py", line 1928, in parseString
    return expatbuilder.parseString(string)
  File "/usr/lib/python2.7/xml/dom/expatbuilder.py", line 940, in parseString
    return builder.parseString(string)
  File "/usr/lib/python2.7/xml/dom/expatbuilder.py", line 223, in parseString
    parser.Parse(string, True)
xml.parsers.expat.ExpatError: no element found: line 239, column 0
[joint_state_publisher-2] process has died [pid 7555, exit code 1, cmd /opt/ros/indigo/lib/joint_state_publisher/joint_state_publisher __name:=joint_state_publisher __log:=/home/ubuntu/.ros/log/6a4eafd8-a702-11e6-98d1-00044b581868/joint_state_publisher-2.log].
log file: /home/ubuntu/.ros/log/6a4eafd8-a702-11e6-98d1-00044b581868/joint_state_publisher-2*.log
[ERROR] [1478753953.368324386]: No link elements found in urdf file

Edit 2: Full urdf xacro.

<?xml version="1.0"?>
<robot name="macroed" xmlns:xacro="http://ros.org/wiki/xacro">
<robot xmlns:sensor="http://playerstage.sourceforge.net/gazebo/xmlschema/#sensor"
xmlns:controller="http://playerstage.sourceforge.net/gazebo/xmlschema/#controller"
xmlns:interface="http://playerstage.sourceforge.net/gazebo/xmlschema/#interface"
xmlns:xacro="http://playerstage.sourceforge.net/gazebo/xmlschema/#interface" name="macroed">
<!-- Convert to xacro-->

    <xacro:property name="width" value="0.2" /> 
    <xacro:property name="leglen" value="0.6" />
    <xacro:property name="polelen" value="0.2" />
    <xacro:property name="bodylen" value="0.6" />
    <xacro:property name="baselen" value="0.4" />
    <xacro:property name="wheeldiam" value="0.07" />
    <xacro:property name="pi" value="3.1415" />

    <material name="blue">
        <color rgba="0 0 0.8 ...