Daily averages from hourly values

[Jeremy S Pal <jpal@xxxxxxx>]

  Hi -

I am trying to plot up daily averages of hourly data.  When I run
the following command, I do not seem to get an average for the
first day:
yes?  list ppt[l=1:744:24@ave]
 01-JUL-1993 00 /  1:   ....
 02-JUL-1993 00 /  2:  10.25
 03-JUL-1993 00 /  3:   4.13
...
 31-JUL-1993 00 / 31:   0.03

Here are the results some commands that may help with this
problem:
yes? list ppt[l=1]
          0.1155
yes? list ppt[l=2]
          2.150
yes? list ppt[l=1:1:1@ave]
          0.1155
yes? list ppt[l=1:2:2@ave]
        ....
yes? list ppt[l=2:2:1@ave]
          2.150
yes? list ppt[l=2:2:2@ave]
          1.455
yes? list (0.5*ppt[l=1]+ppt[l=2]+0.5*ppt[l=3])/2
          1.455
So, it seems that maybe ferret is weighting the outer times by
50%.  In my case, is ferret asking for ppt at l=0 (l=1/2)?  If
so, is there some way to tell ferret not to include l=0?


Any help is greatly appeciated.


  Thank you,

  - Jeremy