[las_users] 7.03 UI and netcdf files with time after noon

[Emanuele Lombardi <emanuele.lombardi@xxxxxxx>]

Dear LAS people,

I noticed a strange behavour of the LAS 7.0.3 UI. It is a problem related to 
the selection of netcdf files having the time past noon. 

With such files it happens to me that LAS asks ferret to plot data of the day 
before the one I select. 

My poor english does'nt allow me to explain properly so I kindly ask you to 
try yourself. Please select the "LAS test" dataset at 
http://clima.casaccia.enea.it:8080/las

You see six files,  they are all identical but the time values. In fact each 
file has the same data but the time value has been changed so that 3 file are 
before noon (04:00, 11:00, 12:00) and 3 are in the afternoon (13:00, 14:00, 
19:00).
I made the 6 files from a single file only modifying its time value using "cdo 
settime". Time dimension of the files is 2 and dates are 29 and 30 June, 
2009.

If you select any of the 04:00, 11:00 or 12:00 o'clock files you are shown the 
ferret plot of the day you ask for.
But if you select any of the 13:00, 14:00 or 19:00 o'clock files  you are 
shown the ferret plot of the day before the one you ask for. Of course, if 
you ask for the first day (29 June) you get an error.

The problem does'nt arise if the "afternoon" netcdf files have only one time.

I hope you could verify my words pointing your browser to the above URL. 
If so I would apreciate any help because I really need to use use LAS on such 
kind of hourly data.
Thank you,
Emanuele.


To help you reproduce the problem it follows what I did to produce the test 
case.

All six files come from a netcdf file which ncdump -v time  is the following:

netcdf file {
dimensions:
        lon = 544 ;
        lat = 160 ;
        time = UNLIMITED ; // (2 currently)
variables:
        float lon(lon) ;
                lon:long_name = "longitude" ;
                lon:units = "degrees_east" ;
                lon:standard_name = "longitude" ;
        float lat(lat) ;
                lat:long_name = "latitude" ;
                lat:units = "degrees_north" ;
                lat:standard_name = "latitude" ;
        double time(time) ;
                time:units = "days since 2005-01-01 00:00" ;
                time:calendar = "standard" ;
        float SeaSurfaceTemperature(time, lat, lon) ;
                SeaSurfaceTemperature:long_name = "Sea Surface Temperature 
(SST) " ;
                SeaSurfaceTemperature:units = "C" ;
                SeaSurfaceTemperature:_FillValue = 999.99f ;

// global attributes:
                :CDI = "Climate Data Interface version 1.3.1" ;
                :Conventions = "CF-1.0" ;
                :nco_openmp_thread_number = 1 ;
                :CDO = "Climate Data Operators version 1.3.1 
(http://www.mpimet.mpg.de/cdo)" ;
data:

 time = 1640.79166666667, 1641.79166666667 ;
}

cdo showtime file.nc
 2009-06-29,19:00 2009-06-30,19:00

>From the above file.nc I used the folloing script to produce oll the other 
files:

cdo settime,04:00 -setgatt,Title,"TIME=04:00" file.nc time04.nc
cdo settime,11:00 -setgatt,Title,"TIME=11:00" file.nc time11.nc
cdo settime,12:00 -setgatt,Title,"TIME=12:00" file.nc time12.nc
cdo settime,13:00 -setgatt,Title,"TIME=13:00" file.nc time13.nc
cdo settime,14:00 -setgatt,Title,"TIME=14:00" file.nc time14.nc
cdo                setgatt,Title,"TIME=19:00" file.nc time19.nc


You can get the netcdf files from: 
<a href="http://clima.casaccia.enea.it/test_las/file.nc";>file.nc</a>
<a href="http://clima.casaccia.enea.it/test_las/time04.nc";>time04.nc</a>
<a href="http://clima.casaccia.enea.it/test_las/time11.nc";>time11.nc</a>
<a href="http://clima.casaccia.enea.it/test_las/time12.nc";>time12.nc</a>
<a href="http://clima.casaccia.enea.it/test_las/time13.nc";>time13.nc</a>
<a href="http://clima.casaccia.enea.it/test_las/time14.nc";>time14.nc</a>
<a href="http://clima.casaccia.enea.it/test_las/time19.nc";>time19.nc</a>

Then I run addXML on each of the above six netcdf files. 
You can also get the <a 
href="http://clima.casaccia.enea.it/test_las/time14.txt";> the xml produced by 
addXML on the file time14.nc</a>. Other xml files only differ in the dataset 
id, name and URL.

At last I modified las.xml and I restarted tomcat.