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Hi Nikitas- > Thanks, we will try reinstalling 2.7 tomorrow and see. The fix should be in today's build. > With regard to your question about the grid, our grid is curvilinear, and > curvilinear grids can be twisted in every direction. Lat-longs for the land > cells of twisted curvilinear grids can only be dummy values if anything. Still not sure I understand this, but okay. ;-) > Yet, what if we cheated? Can we just assign lat=1, long=1, and depth=1 (with > the same sigma transform) to the land cells, and NaN for the mapped quantity > values at these land cells? Would that work in IDV? Would IDV render a field > with holes (NANs in the values of the 3D field, not the location)? Then it wouldn't truly be a grid since the values would not be monotonically increasing/decreasing. I have an idea about a possible solution to this, but I won't be able to implement/test it for a couple of weeks. We have a workshop all next week and are trying to get the 2.7 release finished up. Don Murray > -----Original Message----- > From: Unidata IDV Support [mailto:address@hidden] > Sent: Wednesday, June 03, 2009 1:13 PM > To: address@hidden > Cc: address@hidden; address@hidden; > address@hidden > Subject: [Support #JXE-761208]: IDV with NetCDF including land (and IDV > 2.7beta2) > > Hi Liang- > > > Hi,DonI uploaded two files,one is NYHOPS_noland.cdf, the other is > NYHOPSFrom > > Table.cdf. With IDV 2.7,both can't be read in. But with IDV 2.6, the > volume > > rendering is working perfect for the first cdf file,that's the file with > no > > land included. The second cdf file can't do the volume rendering work > with > > IDV 2.6, in which land is included. > > > > For IDV2.7,the error information is: couldn't get data 2 for the first cdf > > file. > > The error information is:Couldn't get data > > Gridded3DSet: samples values may not be missing. For the second cdf file. > > There was a bug in the netCDF-Java stack that caused the problems with these > files for 2.7. We actually came across that yesterday with another file and > the fix was checked into svn yesterday. I'm not sure when that will > make it into our nightly build. > > The 3D rendering with the missing lat/lons is tricky. The netCDF library > replaces the xpos,ypos with the lat/lon values at each point. For us > to handle the sigma coordinates, we make a mapping from lat,lon,sigma <-> > lat,lon,altitude. We do this so people can slice on sigma levels. > However, we can't do this when the lat/lons are missing because the > transform is not invertible. I'm still unclear why you have missing > lat/lons at any x,y if the grid can be mapped onto the earth. > > I don't really have a solution to that at this point, but will keep > pondering it. > > Don > > Don Murray > > address@hidden> wrote: > > > > > Liang, > > > Please answer Don's questions below for me, with some detail, and upload > on > > > his site: > > > 1) an example that does not work with 2.7 but works with 2.6, and > > > 2) the original (table.txt) version of the grid that does not render due > to > > > land. > > > Please CC me in the response. > > > -Nickitas > > > > > > -----Original Message----- > > > From: Unidata IDV Support [mailto:address@hidden] > > > Sent: Tuesday, June 02, 2009 4:57 PM > > > To: address@hidden > > > Cc: address@hidden > > > Subject: [Support #JXE-761208]: IDV with NetCDF including land (and IDV > > > 2.7beta2) > > > > > > > > > Hi Nickitas- > > > > > > > We took efforts to make our NetCDF output for our NY/NJ Harbor ocean > > > model > > > > CF-compliant, and now IDV renders it in 3D very nicely. We've seen > > > probes, > > > > transects, volume rendering. Very cool! > > > > > > Great! > > > > > > > BUT, > > > > > > > > > > > > > > > > Only if we create sub-arrays that do not include land (NaN lat-lon and > > > out > > > > of range packed values). This is a coastal ocean model, and as such, > land > > > is > > > > part of the full output array. Because the grid is not a nice > rectangle > > > but > > > > quite distorted in the X-Y, lat-long coordinate values on land would > be > > > > nonsensical. But if we try to load the full output NetCDF CF-compliant > > > file > > > > with the native land/ocean array, IDV does not render in 3D. > > > > > > Is there a particular error that is generated? > > > > > > My guess is > > > > that IDV is trying to render the land parts of the array that are NaN > and > > > > fails, because it does not know how to distinguish between contiguous > > > areas > > > > of NaNs (such as land) versus internal NaN such as bad data, and does > not > > > > know what to do with data gaps in general. > > > > > > > > > > > > > > > > Any clues? Have you come up with any smart ways of dealing with this > > > > problem? By the way, IDV 2.7 beta 2 does not work at all for us, only > > > 2.6, > > > > which is interesting in its own. > > > > > > We definitely want to fix what's broke in 2.7b2, so could you point > > > me to a sample data file or upload one to: > > > > > > http://motherlode.ucar.edu/repository/alias/idvupload > > > > > > Once we get that fixed, I can look further into the other issue. Having > > > NaN's for lat/lon is tricky because the netCDF layer translates that > into > > > a lat/lon projection. If there is a dimensionless vertical coordinate, > > > that complicates it further since we have to have a transformation > between > > > lat,lon,sigma <-> lat,lon,alt for the 3D displays. > > > > > > Don Murray > > > > > > Ticket Details > > > =================== > > > Ticket ID: JXE-761208 > > > Department: Support IDV > > > Priority: Normal > > > Status: Open > > > > > > > > > > > > > > > > Ticket Details > =================== > Ticket ID: JXE-761208 > Department: Support IDV > Priority: Normal > Status: Open > > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 8.5.339 / Virus Database: 270.12.50/2150 - Release Date: 06/03/09 > 05:53:00 > > Ticket Details =================== Ticket ID: JXE-761208 Department: Support IDV Priority: Normal Status: Open