A synthetic example showing how to create a Munin graph of the average and trend of data taken from other graphs.

Munin_avg_trend_example.conf

[your.domain;Totals]
  # Comments are hashed

  update no   # This is not a real machine so turn of fetching

  temp.graph_title My Graph   # Name the graph

  # Indicate the data we want to use in this graph (average and trend are dummy values)
  temp.graph_order host1=host1.your.domain:plugin_name.value \
                   host2=host2.your.domain:plugin_name.value \
                   average=host2.your.domain:plugin_name.value \
                   trend=host2.your.domain:plugin_name.value

  # Configure the graph
  temp.graph_args --lower-limit 10 --upper-limit 40
  temp.graph_width 640
  temp.graph_height 360

  # Turn off graphing the raw data
  temp.host1.graph no
  temp.host2.graph no

  # Set the RRDTool parameters see RRDTool for meaning of cdef and commands

  # val1,val2,no of sources,command  
  temp.average.cdef host1,host2,2,AVG

  # Calculate the trend in average over the last 43200 seconds (12 hours)
  temp.trend.cdef average,43200,TREND