NOTICE: This version of the NSF Unidata web site (archive.unidata.ucar.edu) is no longer being updated.
Current content can be found at unidata.ucar.edu.
To learn about what's going on, see About the Archive Site.
NOTICE: This version of the NSF Unidata web site (archive.unidata.ucar.edu) is no longer being updated.
Current content can be found at unidata.ucar.edu.
To learn about what's going on, see About the Archive Site.
I'm not following this closely, but I was bothered by "we now know how to create a netcdf-java compliant trajectory file". netcdf-java is just one tool. There are other tools now, and there will be more in the future. netcdf-java probably supports a subset/superset of the file types defined by the CF DSG standard (which allows a huge number of minor variations). I think a far better goal is to seek to make files which are compliant with the CF DSG standard, and thus with any tool that follows the CF DSG standard. If a given tool (e.g., netcdf-java) can't deal with a valid CF DSG file, then it is a bug in that tool and you can legitimately/reasonably ask the developer to fix the bug. On Thu, Aug 27, 2015 at 12:01 PM, Heiko Klein <Heiko.Klein@xxxxxx> wrote: > Hi Kyle, > > I made now the time-dimension 2-dimensional, i.e. time(obs, trajectory), > removing the one simplification made below. netcdf-java seems now to be > able to read the trajectories. Since the page: > > http://www.unidata.ucar.edu/software/thredds/current/netcdf-java/reference/FeatureDatasets/CFpointImplement.html > already mentions differences from CF, maybe this one could be entered > there, too? (Or maybe it's easy to extend the cdm to support > one-dimensional time-axes?) > > > > I wasn't able to plot trajectories as seen in netcdf-java 2.2. Is it > just me not finding the right buttons or was this feature removed? This > is not critical, but would be nice for debugging. > > > But the most important point is that we now know how to create a > netcdf-java compliant trajectory file. Thanks for your help. > > Heiko > > > On 2015-08-27 20:17, Heiko Klein wrote: > > Hi Kyle, > > > > we're trying to use quite strictly H.4.1 here, with one addition: > > > > Since all trajectories have the same timesteps we use 'time'='obs' and > > we don't have a special obs dimension. According to CF, this is allowed: > > (Chapter H.4.1: "If the trajectories all have the same set of times, the > > time auxiliary coordinate variable could be one-dimensional time(obs), > > or replaced by a one-dimensional coordinate variable time(time), where > > the size of the time dimension is now equal to the number of elements of > > each trajectory. In the latter case, listing the time coordinate > > variable in the coordinates attribute is optional.") > > > > Best regards, > > > > Heiko > > > > > > On 2015-08-27 16:22, Kyle Wilcox wrote: > >> Hi Heiko, > >> > >> At first glace, I can't figure out which CF specification you were > >> trying to adhere to: H.4.1, H.4.2, H.4.3, or H.4.4. It appears you may > >> have tried to adopt H.4.2 to use multiple trajectories, which I'm not > >> sure is supported in NetCDF-Java. > >> > >> Take a look at these Trajectory > >> examples: > https://github.com/asascience-open/CFPointConventions/tree/master/trajectory > . > >> Each folder contains a .cdl, .nc (that will load into NetCDF-Java), and > >> an .ncml file. > >> > >> Hope that helps, > >> Kyle > >> > >> > >> On Thu, Aug 27, 2015 at 4:21 AM, Heiko Klein <Heiko.Klein@xxxxxx > >> <mailto:Heiko.Klein@xxxxxx>> wrote: > >> > >> Hi, > >> > >> I'm trying to read trajectory data with netcdf-java. I've seen > figures > >> of this with netcdf-java 2.2 at > >> > >> > https://www.unidata.ucar.edu/software/thredds/v4.3/netcdf-java/tutorial/PointDatatype.html > >> > >> but both netcdf-4.6 and CF-1.6 have a different layout for > >> trajectory data. > >> > >> > >> > >> I've tried now to generate a netcdf/CF file following the > guidelines at > >> > http://www.unidata.ucar.edu/software/thredds/current/netcdf-java/reference/FeatureDatasets/CFpointImplement.html > >> (see attached file). > >> > >> > >> ToolsUI gives me a 'CoordSys' with trajectory, time, lat, lon and > >> time,lat,lon have the expected axisTypes. Using FeatureScan, I get a > >> coverage of 'Swath(T,Y,X): trajectory', which looks ok, but I get > also > >> an error message: > >> > >> --------- > >> /home/heikok/openoil2.nc4 > >> NetCDF-4 > >> map = 'f:D(2)->R(4)' > >> > >> null > >> > >> CoverageFactory for '/home/heikok/openoil2.nc4' > >> coverage = Swath > >> FeatureDatasetFactoryManager errlog = Table > >> PsuedoStructure(trajectory)/MultidimPseudo(trajectory,time) > featureType > >> TRAJECTORY: lat/lon/time coord not found > >> **Failed to find FeatureDatasetFactory for= > /home/heikok/openoil2.nc4 > >> datatype=TRAJECTORY > >> ---------- > >> > >> > >> According to 'CoordSys', lat/lon/time are availble. > >> > >> The PointFeature/TRAJECTORY wasn't then able to plot the data. Any > idea > >> how I can correct my data to enable plotting in netcdf-java UI? > >> > >> > >> Best regards, > >> > >> Heiko > >> > >> > >> > >> _______________________________________________ > >> netcdf-java mailing list > >> netcdf-java@xxxxxxxxxxxxxxxx <mailto:netcdf-java@xxxxxxxxxxxxxxxx> > >> For list information or to unsubscribe, visit: > >> http://www.unidata.ucar.edu/mailing_lists/ > >> > >> > > > > _______________________________________________ > netcdf-java mailing list > netcdf-java@xxxxxxxxxxxxxxxx > For list information or to unsubscribe, visit: > http://www.unidata.ucar.edu/mailing_lists/ > -- Sincerely, Bob Simons IT Specialist Environmental Research Division NOAA Southwest Fisheries Science Center 99 Pacific St., Suite 255A (New!) Monterey, CA 93940 (New!) Phone: (831)333-9878 (New!) Fax: (831)648-8440 Email: bob.simons@xxxxxxxx The contents of this message are mine personally and do not necessarily reflect any position of the Government or the National Oceanic and Atmospheric Administration. <>< <>< <>< <>< <>< <>< <>< <>< <><
netcdf-java archives: