This archive contains answers to questions sent to Unidata support through mid-2025. Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated. For the most up-to-date information on the use of NSF Unidata software and data services, please consult the Software Documentation first.
> Hi Yuan, > > Thanks for your help. I was able to make the difference. However I need one > more help; one of the grid maps is larger than other grid maps in spatial > extent; so when I make difference large differences are shown for the grids > where one of the maps do not have any grid value. How I can mask those > large difference values? > > > Regards, Tapash > When making difference between two different domains, you need to resample the large domain to the small domain before the calculation. There is a build in formula resampleGrid(largeGrid, smallGrid) can be used in your case. Yuan > > Ticket Details > =================== > Ticket ID: FXH-373138 > Department: Support IDV > Priority: Normal > > > > address@hidden> wrote: > > > > Hi, > > > > > > > > > > > > I am trying to subtract a netCDF grid map from another netCDF grid map to > > > produce a difference netCDF grid map in the IDV. I am using "Layer > > > Difference" from Data -> Formulas -> Grids at the Dashboard, but > > apparently > > > I am able to get success. > > > > > > > > > > > > Would you please point me how I can produce a difference grid map from > > two > > > grid maps? I am using IDV version 4.0u1. > > > > > > > > > > > > I really appreciate your help. > > > > > > > Hi Tapash, > > > > Please reference the tutorial document: > > > > > > https://www.unidata.ucar.edu/software/idv/docs/workshop/formulas/SimpleFormulas.html > > > > > > Yuan > > > > > > > > > Thanks lot. > > > > > > > > > > > > Regards, Tapash > > > > > > > > > > Ticket Details > > =================== > > Ticket ID: FXH-373138 > > Department: Support IDV > > Priority: Normal > > Status: Closed > > > > > > Ticket Details =================== Ticket ID: FXH-373138 Department: Support IDV Priority: Normal Status: Closed