CDO

Jay Su wrote:

We are remapping data1 (lon=[-180,180]) to grid (lon = [0,360]).

If asked: [0,360], no issue
but if asked: [-180,180], the result will on the grid [-180,180] instead of [0,360]

well, you get, what you asked for. so i think this is correct behavior of CDO, isn't it?

Does it cause any issue to any tool? I understand [-180,180] = [0,360].

are you serious? How could anybody know all tools? Sure, [-180,180] and [0,360] describe the same thing, but tools have to be aware of that. CDO is,btw.

Thanks,

Well the user also asks for the grid [0,360]... Does it mean CDO puts subsetting parameters above grid parameters?

No I did not ask about all tools, just the tools you may be aware of.

Jay Su wrote:

Well the user also asks for the grid [0,360]... Does it mean CDO puts subsetting parameters above grid parameters?

CDI does as requested by the user. For a -180,+180 grid, you can user this griddes (the internal default called global_1)

#
# gridID 1
#
gridtype  = lonlat
gridsize  = 64800
xsize     = 360
ysize     = 180
xname     = lon
xlongname = "longitude" 
xunits    = "degrees_east" 
yname     = lat
ylongname = "latitude" 
yunits    = "degrees_north" 
xfirst    = 0.5
xinc      = 1
yfirst    = -89.5
yinc      = 1

whereas the version for 0,360 looks nearly identical

#
# gridID 1
#
gridtype  = lonlat
gridsize  = 64800
xsize     = 360
ysize     = 180
xname     = lon
xlongname = "longitude" 
xunits    = "degrees_east" 
yname     = lat
ylongname = "latitude" 
yunits    = "degrees_north" 
xfirst    = 0.5
xinc      = 1
yfirst    = -89.5
yinc      = 1

Only the xfirst value is different. Both can be used for remapping and will create the corresponding grids.

No I did not ask about all tools, just the tools you may be aware of.

Sorry for the misunderstanding, then - CDO can handle this, plotting tools like Panoply, ncview and ncl can handle this. general mapping tools like python-libraries for plotting for sure can handle this.

Finally: Since this identity is so fundamental I expect all tools to work with this. But: Please check yoursef ;-)

hth
ralf