Re: netcdf files regrid/interpolate problem

Dear Igor,
dsgrid2s requires same dimension of lat and lon. You can use "linint2"
which interpolates from one rectilinear grid to another using bilinear
interpolation.

Please check
http://www.ncl.ucar.edu/Document/Functions/Built-in/linint2.shtml

Thanks

Debasish

> Dear NCL group,
>
> i am a "long time listener, first time caller" on the NCL talk group, been
> using a lot of useful tips from all the members. Now it is the first time
> i
> had to go rogue from an eavesdropper to a participant, so i hope somebody
> will have a clue how my hurdle can be tackled.
>
> The problem is to regrid/interpolate a variable written in a netcdf file,
> to a specific grid/resolution. These are all 2D variables, and in order to
> divide them or make a scatter plot with them - i need to have them on the
> same grids and with identical dimensions.
>
> To make things to the point and to refer to them more easily, i have 3 .nc
> files:
>
> radar_output.nc,
> lid_l2a_output.nc and
> reff_slice_rev.nc,
>
> and these are ncl_filedump outputs of these files:
>
> radar_output.nc:
> dimensions:
> one = 1
> nx = 255
> ny = 1
> nz = 90
> float CPR_Reflectivity ( nz, nx )
> long_name : Reflectivity [94 GHz]
> units : mm^6 m^-3
> plot_title : Reflectivity [mm\U6\D/m\U3\D] [94 GHz]
>
> lid_l2a_output.nc:
> dimensions:
> nx = 51
> ny = 1
> nz = 139
> one = 1
> float Extinction_3 ( nz, nx )
> long_name : Extinction_3
> units : 1/m
> plot_title : Extinction [1/m]
>
> and finally reff_slice_rev.nc
> dimensions:
> nz = 80
> nx = 512
> variables:
> float R_eff ( nz, nx )
> long_name : effective radius
> units : microns
> plot_title : R\deff\u [microns]
>
> It doesn't matter to which grid i eventually need to use for all of them,
> as long as they are the same. Maybe it would be best to get them all to
> lid_l2a_output.nc grid, as it is the lowest one.
>
> Basically, i need to make a scatter plot of CPR_Reflectivity /
> Extinction_3
> vs. R_eff, and
> from what i understand they all need to have the same number of grid
> points
> on both x and z direction. I read in the variables
>
> fin =
> addfile("/data/ECSIMv15/sessions/hr18_ecsimreff_up/dave_20111130182841/
> radar_output.nc","r") ;satellite, hr18
> reflectivity = fin->CPR_Reflectivity(:,:)
> reflectivity=where(reflectivity.le.0,0.0001,reflectivity) ;this is
> eliminating negative values of z
> reflectivity=10.0*log10(reflectivity) ;converting mm6/m3 into dBz
>
> and from some on line examples have understood that i need to manually
> create a new grid to which all the values in memory will be interpolated,
> with something like this:
>
> xinc = 1.0 / (NX - 1)
> yinc = 1.0 / (NZ - 1)
> ii = fspan(0.0, 255.0, NX)
> xo = xinc * ii
> yo = yinc * ii
>
> and then finish with a simple writing of the regrided file, for example
> the
> radar_output.nc.
>
> ;*****Delete an existing netCDF file, if present*****
> ncdf_filename = "regrided_radar.nc"
> if(isfilepresent(ncdf_filename)) then
> system("/bin/rm " + ncdf_filename)
> end if
> ;****************************************************
>
> fout=addfile("/data/ECSIMv15/sessions/hr18_ecsimreff_up/regrided_radar.nc
> ","c")
> fout->CPR_Reflectivity = fin->CPR_Reflectivity(xo|:, yo|:)
>
> It does not work as it is, and the error message i get is:
>
> fatal:Number of dimensions in parameter (0) of (dsgrid2s) is (2), (1)
> dimensions were expected
>
>
> Thank you very much if you have a look-see of my email,
>
> best,
> //Igor
>
>
>
>
>
>
> --
> Dipl.-Met. Igor Stepanov
>
> Faculty of Electrical Engineering, Mathematics and Computer Sciences
> Tel: +31(0)15 2789543
> http://rse.ewi.tudelft.nl
> skype: stepig
> _______________________________________________
> ncl-talk mailing list
> List instructions, subscriber options, unsubscribe:
> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>

_______________________________________________
ncl-talk mailing list
List instructions, subscriber options, unsubscribe:
http://mailman.ucar.edu/mailman/listinfo/ncl-talk
Received on Thu Jan 12 10:23:21 2012