Hi Paulo,
First a quick suggestion - please remember to put a subject into
your messages to the list, so people can see the topic before
reading the message.
I'll point you to some sections of the documentation that may help
you. In the section about the average transform,
http://ferret.pmel.noaa.gov/Ferret/documentation/users-guide/variables-xpressions/XPRESSIONS#_VPINDEXENTRY_439
follow the link where it says "See the General
Information on transformations for important details
about this transformation." In that General Information there
is a paragraph about the distinction between averages using world
coordinates, e.g. time strings, vs index ranges. If this doesn't
seem to explain what you are seeing, you're welcome to write back to
the list showing more detail. Use the LIST command to show a subset
of the data values that you are seeing.
Ansley
On 7/29/2013 10:56 AM, Paulo Santiago
wrote:
Dear
Ferret users,
My
question is quite basic, but I couldn't solve it alone.
I've
been trying to compute the time average of a field using both
'T' (time) and 'L' (index), like that:
!
set wind 1; fill
UCOMP[d=2,x=@ave,L=3:4@AVE]-UCOMP[d=1,x=@ave,L=3:4@AVE];
set wind 2; fill
UCOMP[d=2,x=@ave,t=16-JUN-2021:16-JUL-2021@AVE]-UCOMP[d=1,x=@ave,T=16-JUN-2021:16-JUL-2021@AVE];
!
Being
that my L=3 is the day 16-JUN-2021
and my L=4 is the day 16-JUL-2021.
However the two pictures are
completely different and the right one is that one I compute
using the 'T' axis.
I plot the same picture using other functions, for example
@VAR or @MAX, and in these cases the pictures are identical,
so I wonder if does anyone know why it is happening for the
average? Is there another way to compute the average using L
index that I should be aware?
Many thanks,
--
Paulo Santiago
Ph.D. Student in Meteorology
Brazilian National Institute for Space Research
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