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 Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated.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.
> Well, now we know: > > Creating display: Color-Shaded Plan View > not a cyclic grid > not a cyclic grid > > The file is at www.marinedataliteracy.org/examples/rtgssthr_grb_0.083.grib2 > if you wanna give it a shot. I could have sworn it was a complete globe. > > But wait. Is GRB the problem? > Murray, The dataset is globe but not fit into the standard we use in the IDV. Basically, the IDV check the first and last longitude and expecting the first + 360 to approximate to the last within the 0.0005 range. Your data is within 0.5 range and can not be identified as cyclic grid. I am not sure there is anything we can do. Yuan > Murray > > -----Original Message----- > From: Unidata IDV Support [mailto:address@hidden] > Sent: Wednesday, September 03, 2014 5:22 PM > To: address@hidden > Cc: address@hidden > Subject: [IDV #PKC-150970]: Question about 0-360 grids versus -180-to-+180 > grids > > Murray, > > Sorry about that. It is "lonFlip(a)". Note that the formula is camel-cased. > > Best, > > Unidata IDV Support > > > I had already been down that road several times last night. Here's > > the inevitable result for lonflip(a) > > > > Creating display: Color-Shaded Plan View > > NameError: name 'lonflip' is not defined org.python.core.PyException > > > > Is there something I need to activate prior to this? Or is lonflip(a) > > exactly correct? > > > > Murray > > > > -----Original Message----- > > From: Unidata IDV Support [mailto:address@hidden] > > Sent: Wednesday, September 03, 2014 3:25 PM > > To: address@hidden > > Cc: address@hidden > > Subject: [IDV #PKC-150970]: Question about 0-360 grids versus > > -180-to-+180 grids > > > > Murray, > > > > In the field selector, go to "Formulas" Data Sources. > > > > Select Grids > "Define a grid diagnostic". > > > > Select a Display of Color-Shaded Plan View or the display of your choice. > > > > Click Create Display. > > > > This action will bring forth an input window. > > > > Enter the formula "lonflip(a)" > > > > Click OK > > > > Now select the relevant field in the pop-up "Field Selector" dialog. > > > > Click OK. > > > > These actions should result in the desired image. > > > > Let us know if you have trouble. > > > > Best, > > > > Unidata IDV Support > > > > > Please put an old man out of his misery, and tell him exactly where are > > > the grid diagnostic formulas. Your tool sounds perfect, but I have no > > > idea where to look. > > > > > > > > > -----Original Message----- > > > From: Unidata IDV Support [mailto:address@hidden] > > > Sent: Tuesday, September 02, 2014 1:31 PM > > > To: address@hidden > > > Cc: address@hidden > > > Subject: [IDV #PKC-150970]: Question about 0-360 grids versus > > > -180-to-+180 grids > > > > > > Murray, > > > > > > Question. What projection are you using for your data? If you are > > > using a lat/lon projection there may be a workaround. In particular, > > > there is a grid diagnostic formula called "lonflip" that may offer a > > > solution. From the > > > documentation: > > > > > > "Flip the longitudes in a grid from -180-180 to 0-360 (or vice-versa). > > > Only works for cyclic rectilinear grids." > > > > > > Best, > > > > > > Unidata IDV Support > > > > > > > This is very good news. There is an equivalent "tool" in Saga GIS that > > > > works well, and their code is public domain. Are you interested? > > > > > > > > > > > > -----Original Message----- > > > > From: Unidata IDV Support [mailto:address@hidden] > > > > Sent: Tuesday, September 02, 2014 12:05 PM > > > > To: address@hidden > > > > Cc: address@hidden > > > > Subject: [IDV #PKC-150970]: Question about 0-360 grids versus > > > > -180-to-+180 grids > > > > > > > > Murray, > > > > > > > > We are in the planning stages here at Unidata to resolve this issue. > > > > Unfortunately, it requires "deep surgery" and will take time to resolve > > > > so we do not have an immediate solution for this problem at this time. > > > > But it will get fixed eventually. > > > > > > > > Best, > > > > > > > > Unidata IDV Support > > > > > > > > > Folks, > > > > > > > > > > I have a grib2 file that runs from 0-360, and it's no problem to > > > > > display or subset any areas that fit within this frame. But I'd > > > > > like to display a grid over all of Africa, and that would cross > > > > > the 360-degree right side. Is there a control or function that > > > > > splits the > > > > > 0-360 grid and combines the halves into a -180-to-+180 map? Or any > > > > > equivalent trick I don't know about? > > > > > > > > > > Murray > > > > > > > > Ticket Details > > > > =================== > > > > Ticket ID: PKC-150970 > > > > Department: Support IDV > > > > Priority: Normal > > > > Status: Open > > > > > > > > > > > > > > > > > Ticket Details > > > =================== > > > Ticket ID: PKC-150970 > > > Department: Support IDV > > > Priority: Normal > > > Status: Closed > > > > > > > > > > > > Ticket Details > > =================== > > Ticket ID: PKC-150970 > > Department: Support IDV > > Priority: Normal > > Status: Closed > > > > > > > Ticket Details > =================== > Ticket ID: PKC-150970 > Department: Support IDV > Priority: Normal > Status: Closed > > Ticket Details =================== Ticket ID: PKC-150970 Department: Support IDV Priority: Normal Status: Open