Hi -- reading my response, I should have said for option 1:
Define a new time axis on a gregorian calendar, regrid your data to
that new axis, and then use @MOD to make a climatology with
month_reg.
Ansley
Ansley Manke wrote:
Hi Emile,
Your data must be on a time axis with a non-gregorian calendar. There
are two different solutions to this.
1) Define a new time axis on a gregorian calendar, and then use @MOD to
make a climatology with month_reg.
2) Define your own climatological axis having the same calendar as your
input data. Use the number of days per year, divide by 12 and center
the points within the months. Here are the number of days per year for
the different calendar axes, from the Users Guide.
|
calendar
name
|
number
of days/year
|
notes
|
|
GREGORIAN
or STANDARD
|
365.2425
|
default
calendar
|
|
JULIAN
|
365.25
|
with
leap years
|
|
NOLEAPor
COMMON_YEAR
|
365
|
no
leap years
|
|
360_DAY
|
360
|
each
month is 30 days
|
If you look at the month_reg calendar from the climatological_axes
dataset,
yes? use climatological_axes
yes? list t[gt=month_reg], tbox[gt=month_reg], tboxlo[gt=month_reg],
tboxhi[gt=month_reg]
You'll see how that axis is set up, for the Gregorian calendar. You
should be able to do something similar. Your DEFINE AXIS command should
use a start time axis in year 0000, and use the /MODULO qualifier.
Ansley
Emilie Vanvyve wrote:
Hello
Ansley,
Sorry for the delay of this answer, I've been caught on another urgent
work.
Here is the error I'm returned when I use @MOD to get a monthly
climatology from a several-year data file (cfr joined e-mails for
further details):
yes? use CMAP.1979-2002.nc
yes? use climatological_axes
*** NOTE: regarding /opt/ferret/go/climatological_axes.cdf ...
*** NOTE: Climatological axes SEASONAL_REG, MONTH_REG, and
MONTH_IRREG defined
yes? cancel data climatological_axes
yes? show data
currently SET data sets:
1> ./CMAP.1979-2002.nc (default)
name title I J K L
RAIN1 precipitation (gauge, satellite 1:144 1:72 ... 1:288
ERROR1 relative error for rain1 1:144 1:72 ... 1:288
RAIN2 precipitation (gauge, satellite 1:144 1:72 ... 1:288
ERROR2 relative error for rain2 1:144 1:72 ... 1:288
yes? let clim_rain = rain1[d=1,x=10,y=0,gt=month_reg@mod]
yes? list clim_rain
**ERROR: regridding: only @ASN, @LIN, or @NRST regridding between
calendar types: 360_DAY, GREGORIAN
yes?
Does it help?
Emilie
Le 29 avr. 2005, à 18:12, Ansley Manke a écrit :
Hi Emilie,
What trouble did you have when you tried using @MOD? That is really
what you want to use, to average all the January values, then all the
February values, and so on, returning a 12-month result.
yes? use CMAP.1979-2
yes? use climatological_axes
yes? cancel data climatological_axes ! the axes will
still
be defined
yes? let clim_rain = rain1[d=1,x=10,y=0,gt=month_reg@mod]
yes? list clim_rain
Emilie Vanvyve wrote:
Hello dear Ferret users,
I have the CMAP monthly data from 1979 to 2002 and would like to get
the mean values for every January, February..., and December. I looked
at the online manual and the FAQ and discovered the existence of the
"climatological_axes". I tried it, could not use the @MOD (as advised)
and so I used the @ASN.
When I check the results, Ferret just took my first year and copied
it repeatively across the next years, so that the year 1980 in the new
climatological variable = 1979 values of the original variable, the
year 1981 = 1979, and so on and so forth.
Example: I focus on one point (around 10°N 0°E).
yes? use CMAP.1979-2002.nc
yes? show data
currently SET data sets:
1> ./CMAP.1979-2002.nc (default)
name title I J K L
RAIN1 precipitation (gauge, satellite 1:144 1:72 ... 1:288
ERROR1 relative error for rain1 1:144 1:72 ... 1:288
RAIN2 precipitation (gauge, satellite 1:144 1:72 ... 1:288
ERROR2 relative error for rain2 1:144 1:72 ... 1:288
yes? list rain1[d=1,l=1:24,x=10,y=0]
VARIABLE : precipitation (gauge, satellite, models)
(mm/day)
DATA SET : CPC Merged Analysis of Precipitation (CMAP)
FILENAME : CMAP.1979-2002.nc
SUBSET : 24 points (TIME)
CALENDAR : 360_DAY
LONGITUDE: 8.8E
LATITUDE : 1.2S
8.8E
4
30-JAN-1979 / 1: 4.870
30-FEB-1979 / 2: 5.780
30-MAR-1979 / 3: 4.190
30-APR-1979 / 4: 6.630
30-MAY-1979 / 5: 4.130
30-JUN-1979 / 6: 0.530
30-JUL-1979 / 7: 0.620
30-AUG-1979 / 8: 0.180
30-SEP-1979 / 9: 0.400
30-OCT-1979 / 10: 2.020
30-NOV-1979 / 11: 7.650
30-DEC-1979 / 12: 4.780
30-JAN-1980 / 13: 4.820
30-FEB-1980 / 14: 2.680
30-MAR-1980 / 15: 8.200
30-APR-1980 / 16: 4.220
30-MAY-1980 / 17: 2.240
30-JUN-1980 / 18: 0.530
30-JUL-1980 / 19: 0.800
30-AUG-1980 / 20: 0.290
30-SEP-1980 / 21: 2.660
30-OCT-1980 / 22: 8.630
30-NOV-1980 / 23: 7.130
30-DEC-1980 / 24: 3.550
yes? use climatological_axes
*** NOTE: regarding /opt/ferret/go/climatological_axes.cdf
...
*** NOTE: Climatological axes SEASONAL_REG, MONTH_REG, and
MONTH_IRREG defined
yes? let clim_rain = rain1[d=1,x=10,y=0,gt=month_reg@asn]
yes? list clim_rain[l=1:24]
VARIABLE :
RAIN1[D=CMAP.1979-2002,X=10,Y=0,GT=MONTH_REG@ASN]
SUBSET : 24 points (TIME)
LONGITUDE: 8.8E
LATITUDE : 1.2S
8.8E
4
16-JAN / 1: 4.870
15-FEB / 2: 5.780
17-MAR / 3: 4.190
16-APR / 4: 6.630
16-MAY / 5: 4.130
16-JUN / 6: 0.530
16-JUL / 7: 0.620
16-AUG / 8: 0.180
15-SEP / 9: 0.400
16-OCT / 10: 2.020
15-NOV / 11: 7.650
16-DEC / 12: 4.780
15-JAN / 13: 4.870
14-FEB / 14: 5.780
17-MAR / 15: 4.190
16-APR / 16: 6.630
17-MAY / 17: 4.130
16-JUN / 18: 0.530
17-JUL / 19: 0.620
16-AUG / 20: 0.180
15-SEP / 21: 0.400
16-OCT / 22: 2.020
15-NOV / 23: 7.650
16-DEC / 24: 4.780
So clim_rain(1979) = rain(1979), clim_rain(1980) = rain(1979), ...!
Where am I wrong?
Thanks for any suggestion!
Emilie V.
____________________________________________________________
Emilie VANVYVE
Physicist, PhD student
Université catholique de Louvain (UCL)
Institut d'astronomie et de géophysique G. Lemaître (ASTR)
Chemin du Cyclotron, 2
1348 Louvain-la-Neuve (Belgium)
Phone: +32-(0)10-473300 // Fax: +32-(0)10-474722
E-mail:
vanvyve@astr.ucl.ac.be //
Web: www.astr.ucl.ac.be
____________________________________________________________
Emilie VANVYVE
Physicist, PhD student
Université catholique de
Louvain (UCL)
Institut d'astronomie et de géophysique G. Lemaître (ASTR)
Chemin du Cyclotron, 2
1348 Louvain-la-Neuve (Belgium)
Phone: +32-(0)10-473300 // Fax: +32-(0)10-474722
E-mail: vanvyve@astr.ucl.ac.be //
Web: www.astr.ucl.ac.be
|