Hi,
As you say, currently Ferret has just 4 dimensions, although we are aware that datasets like this are becoming more common, and have plans to add more dimensions to Ferret to allow for more dimensions. Unfortunately Ferret does not have a way to skip a dimension when opening a dataset. You would need something like USE/ORDER=xyz_t but we don't have such a syntax.
I had the idea that at least you could use the browser interface and download the data from
http://ensembles.ecmwf.int/thredds/dodsC/ocean/ecmwf/eg/thetao.html I tried choosing all the variables, with for the ensemble coordinate choose only one step (0:1:0) to pick the first one. It turns out that only the coordinates are returned. Interestingly on that form,the coordinate variable
ensemble is not listed among the variables, even though the other coordinates Time Longitude, Latitude, Depth are listed.
Does anyone else have other workarounds for accessing data with more than 4 dimensions for use in Ferret? There may be nco operators that could be used to create a file with just the 4 dimensions you want.
Ansley
Haoping Yang wrote:
I am having trouble to load temperature data from some OPeNDAP servers such as http://ensembles.ecmwf.int/thredds/dodsC/ocean/ecmwf/eg/thetao.html. From the web browser, one can open this link and see the data structure. The variable 'thetao' has 5 dimensions: *[time = 0..575]*[ensemble = 0..4][level = 0..32][latitude = 0..178][longitude = 0..359]. The dimension 'ensemble' is useless to me. When I try to load the data via ferret, ferret uses 'ensemble=0..4' as the time dimension and no temperature data can be loaded. Ferret assumes the data has four dimensions instead of five. I don't know how to remove the dimension 'ensemble' and let 'time' to point to the axis 'T' (index 'L'). There must be some tricks to load this data. I guess it might be something like "yes? use/ORDER=.... URL" and could be very easy for some ferret experts. Please help me. Thanks
--------------------------------------------------------------------------------------------------------------------------
yes? use "http://ensembles.ecmwf.int/thredds/dodsC/ocean/ecmwf/eg/thetao"
yes?
yes? show data
currently SET data sets:
1> http://ensembles.ecmwf.int/thredds/dodsC/ocean/ecmwf/eg/thetao (default)
name title I J K L
INSTITUTION
Institution responsible for the ... ... ... ...
EXPERIMENT_ID
Experiment identifier ... ... ... ...
REALIZATION
Number of the simulation in the 1:5 ... ... ...
SOURCE Method of production of the dat ... ... ... ...
THETAO Potential temperature ref to su 1:360 1:179 1:33 1:5
yes?
yes? show grid THETAO
GRID GRM3
name axis # pts start end
LONGITUDE LONGITUDE 360mr 0E 1W
latitude LATITUDE 179 r 89S 89N
level DEPTH (m) 33 i- 0 5500
ENSEMBLE T 5 r 1 5
yes?
yes?
----------------------------------------------------------------------------------------------------------------------
*** *