<rrd_graph_def>
  <options>
    <vertical_label>Knots</vertical_label>
  </options>
  <datasources>
    <def>
      <name>windSpeed</name>
      <rrd>${rrdFile}</rrd>
      <source>windSpeed</source>
      <cf>AVERAGE</cf>
    </def>
    <cdef>
      <name>windSpeedKnots</name>
      <rpn>windSpeed,0.868976242,*</rpn>
    </cdef>
    <def>
      <name>windGust</name>
      <rrd>${rrdFile}</rrd>
      <source>windGust</source>
      <cf>MAX</cf>
    </def>
    <cdef>
      <name>windGustKnots</name>
      <rpn>windGust,0.868976242,*</rpn>
    </cdef>
  </datasources>
  <graph>
    <line>
      <datasource>windSpeedKnots</datasource>
      <color>#FF0000</color>
      <legend>Wind speed</legend>
    </line>
    <line>
      <datasource>windGustKnots</datasource>
      <color>#0000FF</color>
      <legend>Gusting</legend>
    </line>
  </graph>
</rrd_graph_def>