NCL Home > Documentation > Functions > WRF, Interpolation


Interpolates ARW WRF 2D model data along a given line (deprecated).


load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"      ; These two libraries are automatically
load "$NCARG_ROOT/lib/ncarg/nclscripts/wrf/WRFUserARW.ncl"    ; loaded from NCL V6.4.0 onward.
                                                              ; No need for user to explicitly load.

	function wrf_user_intrp2d (
		var2d   : numeric,  
		loc [*] : numeric,  ; up to four values
		angle   : numeric,  
		res [1] : logical   

	return_val  :  numeric



Data that will be interpolated. The rightmost dimensions of this array are ny x nx.


Interpolation information. Can contain up to four scalar values.

Use 2 values if extracting a line through a given point on the model domain. The two values represent the x/y location through which the line will pass. Must also specify angle in this case.

Use 4 values if extracting data from point A to point B. The 4 values represent the x/y locations of points A and B.


Only valid if a line will be extracted through a given point on the model domain. 0.0 represents S-N and 90.0 W-E.


Set to True if extracting a line from point A to point B; otherwise set to False.

Return value

Data interpolated to a specified line on the model domain.


This function is deprecated in NCL version 6.6.0. Use wrf_user_interp_line as a replacement, which allows you to specify the cross section using grid points or lat/lon values.

This function interpolates 2D model data onto a specified line.

Note: in NCL V6.5.0 a bug was fixed in this routine and in wrf_user_intrp3d in which the 0th grid point was not being included when setting up the output domain, causing the output array to be missing a grid point in the rightmost dimension.

wrf_user_intrp2d is part of a library of functions and procedures in WRFUserARW.ncl written to help users plot ARW WRF model data.

See Also

wrf_user_interp_line, wrf_user_interp_level, wrf_user_vert_cross


Example 1

  a = addfile("","r")

  wks = gsn_open_wks("x11","test")

  t2 = wrf_user_getvar(a,"T2",-1)        ; get T2 data for all time periods

  dims = dimsizes(t2)

  plane = (/ dims(2)/2, dims(1)/2 /)       ; pivot point (x,y) through center of domain   
  angle = 90.                              ; plot from west to east
  opts = False                             ; start and end point not supplied

  X_plane = wrf_user_intrp2d(t2,plane,angle,opts)

You can see some other example scripts and their resultant images at: