Re: regridding data

[Ansley Manke <ansley.b.manke@xxxxxxxx>]

Hi Mulyono,
Yes, you can easily do this.  There is no need to add a variable "zero";
that method is used when we want to put a variable onto a grid that has
more dimensions than the original variable.

You just need to define the new axes as you have done, and define
your new variable on the desired grid as follows:

  use/regulart monthly.globe.nc
  DEFINE AXIS/X=5e:355e:5 ax_x
  DEFINE AXIS/Y=35s:35n:5 ax_y
  DEFINE GRID/like=monthly/x=ax_x/y=ax_y grd
  LET monthly5deg = monthly[g=grd]

This will use linear interpolation to put the data on the 
new grid.  Linear regridding is the default method.  If you 
like, you can specify another method of regridding with a 
transformation like @asn or @ave

  LET monthly5deg = monthly[g=grd@ave]

Please see Chapter 4, section 2.4 in the Users Guide (in the index, look 
up the
topic "regridding, syntax and examples") for more discussion of regridding.

Ansley Manke

R Prabowo wrote:

> Hi ferreters,
>
> Is there any way that i can regrid data into smaller or grater x and y axis?
> I have been trying to regrid data[x=0:375.5:2.5, y=40s:40n:2.5] into data'[x=5e:355e:5, y=35s:35n:5] using
>
> use/regulart monthly.globe.nc
> show data
> DEFINE AXIS/X=5e:355e:5 ax_x
> DEFINE AXIS/Y=35s:35n:5 ax_y
> DEFINE GRID/like=monthly/x=ax_x/y=ax_y grd
> LET zero = 0*x[g=grd]+0*y[g=grd]+0*t[g=grd]
> LET monthly5deg = monthly + zero                          !    ***
> save/clobber/file=monthly5deg.globe.nc monthly5deg  !    ***
>
> This script gave error warning as:
>
> *** NOTE: Ambiguous coordinates on X axis: MONTHLY5DEG + ZERO
> **ERROR: inconsistent sizes of data regions: X axis
>          ZERO has 73 points (I=00:72)
>          expression has 144 points (I=001:144)
> LIST/FORMAT=CDF/clobber/file=monthly5deg.globe.nc MONTHLY5DEG
> Command file, command group, or REPEAT execution aborted
>
> When I changed line ***s into:
> LET monthly5deg = monthly[g=grd@asn] + zero
> save/clobber/file=monthly5deg.globe.nc monthly5deg
>
> the script worked, but the values of monthly5deg[i=1:73,j=1:17] in monthly5deg.globe.nc will be exactly the values of monthly[i=1:73,j=1:17] in monthly.globe.nc 
> Any one can give me clues? Thank you very much.
> cheers..
>
>
> Mulyono
>