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NOTICE: This version of the NSF Unidata web site (archive.unidata.ucar.edu) is no longer being updated.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.
> Hello, I need help with my netcdf file. It does not appear that I am > formatting the time variable correctly, because IDV does not recognize that > variable when i read my file in. I can send a netcdf file I have made as an > example. > > Thank you, > > Sonja You didn't have any attribute for the time variable. At least you need to add :units = "hours since 1970-01-01"; :_CoordinateAxisType = "Time"; Yuan > ________________________________________ > From: Behnke, Sonja > Sent: Friday, May 09, 2014 12:24 PM > To: address@hidden > Subject: RE: [IDV #SUF-224604]: netcdf file formatting issue > > Thanks again. I believe I added a time dimension/variable according to your > instructions, but I still don't see the time in IDV. Can you tell me what I > am doing wrong? I attached a file that should have a time variable in it. > > Thank you > > Sonja > ________________________________________ > From: Unidata IDV Support [address@hidden] > Sent: Friday, May 09, 2014 12:11 PM > To: Behnke, Sonja > Cc: address@hidden > Subject: [IDV #SUF-224604]: netcdf file formatting issue > > > Thank you for your help. > > > > I have been able to make a file that IDV reads in. One thing I did not yet > > include in my netcdf file is the date/time that the data correspond to. > > Should this be a variable or an attribute of a variable? When I look at my > > colleague's data in the 'field selector' if IDV I see the time in the box > > below the displays box. How should time be stored in the netcdf file? are > > seconds of day ok? julian day? > > > > Thank you, > > > > Sonja > > Sonja, > The time dimension associates with a time variable, and the data/time > information is stored in this time variable. There are many way to do this, > basically, the most important information is the unit of this variable, for > example: > > double time(time=10); > :long_name = "reference time"; > :units = "hours since 1970-01-01"; > :_CoordinateAxisType = "Time"; > > > if its unit is seconds, > > double time(time=10); > :long_name = "time of stroke"; > :units = "seconds since 1970-01-01 00:00:00"; > :_CoordinateAxisType = "Time"; > > > Hope this can help. > > > Yuan > > ________________________________________ > > From: Unidata IDV Support [address@hidden] > > Sent: Wednesday, May 07, 2014 12:43 PM > > To: Behnke, Sonja > > Cc: address@hidden > > Subject: [IDV #SUF-224604]: netcdf file formatting issue > > > > > I uploaded two files. The other was called > > > lma_Redoubt_20090323_1230_ev.nc > > > > > > This one has a 200x200 element array, representing pixels on a map, and > > > the value is the number of events in the pixel. I have not yet gone to > > > the trouble to extract the lat/lon coordinates for each array element. > > > > > > However, the data from the file you looked at is data and contains "real > > > variables." My data is the lat/lon/time of radiation events by > > > lightning. I want to overlay their location onto other data my > > > colleagues have (who use IDV). If you wanted, I could just make another > > > dummy variable with the same length as the lat/lon and fill it with ones, > > > but I don't see the point in that. Alternatively, you could consider the > > > time variable the "real variable." > > > > > > Sonja > > > > > > Sonja, > > The second file is not a good netCDF file too. Only a variable and two > > dimensions in this file. To construct a good netCDF file, you need to have > > dimensions and associated variables, and projection, "real variables", and > > global attributes. Each variable should has its own attribute, such as > > unit, standard name, coordinate axises, and so on.... In general, the > > structure of lat lon projection gridded dataset is the simplest. > > Here is the web page for more details information: http://cfconventions.org/ > > > > > > Yuan > > > > > ________________________________________ > > > From: Unidata IDV Support [address@hidden] > > > Sent: Tuesday, May 06, 2014 5:28 PM > > > To: Behnke, Sonja > > > Cc: address@hidden > > > Subject: [IDV #SUF-224604]: netcdf file formatting issue > > > > > > > Hello, > > > > > > > > Thank you. I have uploaded the two netcdf files I discuss below. > > > > > > > > Sonja > > > > > > > > > I am checking the dataset named lma_Redoubt_20090323_1230.nc, is this the > > > one you uploaded? The problem is that there is no > > > grided variable in this file, only lat/lon/time coordinate variables. You > > > need to add at least one real variable, such as temperature or pressure, > > > based on these coordinate variables. > > > > > > > > > > > > Yuan > > > > ________________________________________ > > > > From: Unidata IDV Support [address@hidden] > > > > Sent: Friday, May 02, 2014 7:59 PM > > > > To: Behnke, Sonja > > > > Cc: address@hidden > > > > Subject: [IDV #SUF-224604]: netcdf file formatting issue > > > > > > > > Sonja, > > > > > > > > Can you upload your data here and let us know when it is uploaded? > > > > > > > > http://motherlode.ucar.edu/repository/alias/idvupload > > > > > > > > Best, > > > > > > > > Unidata IDV Support > > > > > > > > > > > > > Hello, > > > > > > > > > > I am trying to collaborate with a colleague who uses IDV to visualize > > > > > her modeling results. I have my own data that I would like to > > > > > overlay on hers using IDV. I use IDL, and I am trying to export my > > > > > data into netCDF format. I know how to do this, but I don't know > > > > > what IDV is expecting of me. Let me describe my data: > > > > > > > > > > At simplest I have three arrays: time, latitude and longitude. > > > > > > > > > > time[i] = time of event > > > > > latitude[i] = latitude of event > > > > > longitude[i] = longitude of event > > > > > > > > > > I wrote a program in IDL to make a netcdf file of three variables: > > > > > time, latitude, and longitude. I know I did this correctly because I > > > > > reread the file back in to IDL and was able to extract my arrays. > > > > > > > > > > But, IDV doesn't know what to do with my data. It complains that I > > > > > don't have any "gridded" data in my file. So, I took my data in IDL > > > > > and made a 200x200 element array of the density of my events with > > > > > respect to lat and lon. So each element of the array is a pixel on a > > > > > map, and the value represents how many events were in that pixel. I > > > > > saved that 200x200 array in a netcdf file, but alas, IDV doesn't get > > > > > it. > > > > > > > > > > So, I realize I don't know what IDV is expecting here with my data, > > > > > but I would like to format my data so that it understands it and I > > > > > could use IDV to plot it on a map. > > > > > > > > > > Can you help with this? > > > > > > > > > > Thank you, > > > > > > > > > > Sonja Behnke > > > > > > > > > > > > > > > > > Ticket Details > > > > =================== > > > > Ticket ID: SUF-224604 > > > > Department: Support IDV > > > > Priority: Normal > > > > Status: Open > > > > > > > > > > > > > > > > > Ticket Details > > > =================== > > > Ticket ID: SUF-224604 > > > Department: Support IDV > > > Priority: Normal > > > Status: Open > > > > > > > > > > > > Ticket Details > > =================== > > Ticket ID: SUF-224604 > > Department: Support IDV > > Priority: Normal > > Status: Closed > > > > > > > Ticket Details > =================== > Ticket ID: SUF-224604 > Department: Support IDV > Priority: Normal > Status: Closed > > Ticket Details =================== Ticket ID: SUF-224604 Department: Support IDV Priority: High Status: Open