NSF Unidata

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[IDV #PKC-150970]: Question about 0-360 grids versus -180-to-+180 grids

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 Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated.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.



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