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

> Yuan,
> 
> I'm wondering how/if IDV detects the existing range (0-360 or -180-+180) when 
> a change is being arranged.  Is it automatic?  I was never asked during my 
> tests.
> 
> Murray
> 

Murray,

     The dataset is latlon projection and the IDV and easily finds the 
coordinate to get the value of longitude. It is automatic.


Yuan
> -----Original Message-----
> From: Unidata IDV Support [mailto:address@hidden]
> Sent: Thursday, September 04, 2014 5:00 PM
> To: address@hidden
> Cc: address@hidden
> Subject: [IDV #PKC-150970]: Question about 0-360 grids versus -180-to-+180 
> grids
> 
> > 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
> 
> 


Ticket Details
===================
Ticket ID: PKC-150970
Department: Support IDV
Priority: Normal
Status: Open