[Thread Prev][Thread Next][Index]

Re: [EXTERNAL] Re: [ferret_users] ensemble or compare data from two time series



Dear Sayrabh,

Thank you for your script.😸 Your method worked if I regrid my historical runs to RCPs.😁 However, I still want to keep my historical time axis as 1950-2005 and RCP time axis as 2006-2099. But if I want to keep the time axis, I still get the same error. Thestrange thing is that even I do the most simple calculation:

contour PRECIPITATION[d=1,L=@AVE]-PRECIPITATION[d=2,L=@AVE]
*** NOTE: Ambiguous coordinates on T axis: PRECIPITATION[D=1,L=@AVE]-PRECIPITATION[D=2,L=@AVE]
**ERROR: illegal limits: PRECIPITATION is not in the range T=30-DEC-2005 12:00:30-DEC-2099 00:00@AVE
Axis extremes are T=30-DEC-1949 12:00:30-DEC-2005 00:00

I didn't regrid anything, I just simply read my data in and Ferret won't let me compare the average value.

By the way, for your jnl,

set list/xchunk=120/ychunk=63/zchunk=12/tchunk=66/echunk=5/deflate=2/shuffle/ncformat=4
save/i=1/j=1/k=1/l=1/m=1/ilimits=1:360/jlimits=1:126/klimits=1:36/llimits=1:132/mlimits=1:20/file=histrcp-2005-2015.nc/clob heatcal

why do you use 360 as your limits when your echunk is 5?

Thank you very much and stay healthy,

Xiaoyu


On Tue, Dec 28, 2021 at 5:51 AM saurabh rathore <rohitsrb2020@xxxxxxxxx> wrote:
Axis extremes are T=30-DEC-2005 12:00:30-DEC-2099 00:00


I am using Pyferret v7.6 on Linux 4.15.0-1089-azure. I am wondering how to solve this problem.

Stay healthy,

Xiaoyu


On Wed, Nov 24, 2021 at 6:24 PM Ansley Manke <a.c.manke@xxxxxxxxx> wrote:
[Caution: Email from External Sender. Do not click or open links or attachments unless you know this sender.]

Hi,

Your datasets do not share a time range, so this is not a typical ensemble.

Usually, you can define an ensemble when the datasets do not have the same space/time grids, by first defining a regridding operation so that all datasets have the same space/time grid as the first dataset in your list. On the page,

../../documentation/users-guide/commands-reference/DEFINE.html#_define_data_agg

scroll down in that page to find "Ensemble Examples". Example 3 shows how to define an ensemble for data on two different grids, including for this data a modulo regridding operation to define variables with consistent grids. The variable names must also match, so that example also shows how to rename the file variable within the Ferret session, and then define the new regridded variables using the desired names.


I am not sure what commands you tried using @AVE. If you did a time average, then the resulting grid no longer depends on time, so there should not be an error message about time axes. Look at this example:

! Make a file containing the variables in the first dataset, averaged in time.
! An ensemble needs one file with the grid that is going to be used in the
! ensemble; not all of the grids can come from LET definitions.

yes? use dataset_1
yes? let/like=precip p_tave = precip [t=@ave]
yes? save/file=data1.nc p_tave
yes? cancel data 1

! Now open this data and define variables in the other dataset(s) so that
! they can be included in an ensemble.

yes? use data1.nc

yes? use dataset_2
yes? let/d=2/like=precip p_tave = precip[t=@ave,gxy=p_tave [d=1]]

yes? ensemble time_ave = 1,2

! The ensemble dataset should contain the variable p_tave with a grid in X-Y-E

yes? show data time_ave


On 11/18/2021 3:22 PM, Xiaoyu Bai wrote:
Dear ferreters,

I am trying to ensembleRCPs (2005-2099) and control runs (1949-2005) together but keep getting T axis differs error.

*** NOTE: Variable "PRECIPITATION" excluded from aggregate: T axis differs among members
**ERROR: error defining aggregate dataset: No valid datasets or datasets share no variables that can be aggregated.

It makes sense for pyferret to think the time axis are different. But comparing the@AVE value from different time series should also make sense topyferret. I am wondering how to solve this problem.

By the way, I already tried to read data in separatelyand do@AVE first then compare. It still showed the same errorbecause the data still come from different time series.


--
Xiaoyu (she/her)


--
Xiaoyu (she/her)


--


REGARDS

Saurabh Rathore
Research Scholar (PhD.)
Centre For Oceans, Rivers, Atmosphere & Land Science Technology
Indian Institute Of Technology, Kharagpur
contact :- 91- 8345984434


--
Xiaoyu (she/her)

[Thread Prev][Thread Next][Index]