CURV_TO_RECT - Ferret/PyFerret Documentation

CURV_TO_RECT (V, mapping)

Applies the mapping computed by function CURV_TO_RECT_MAP to interpolate data from a curvilinear to a rectilinear latitude-longitude grid. This computation employs a spherical interpolation code written at GFDL; the Ferret developers are responsible for its implementation as an external function.

Arguments:	V	Variable on the source curvilinear grid
	mapping	mapping from the source grid to a rectilinear grid
Result Axes:	X	Inherited from mapping
	Y	Inherited from mapping
	Z	Inherited from V
	T	Inherited from V

This is a grid-changing function. Indicate limits on the argument axes with square brackets []. See the note on grid-changing functions in Chapter 3

Example of calls to CURV_TO_RECT_MAP and CURV_TO_RECT:

yes? use my_curvilinear_data.nc
yes? show data
currently SET data sets:
1> /.my_curvilinear_data.nc (default)
name title I J K L
GEOLON geographic longitude of grid 1:180 1:173 .. ..
GEOLAT geographic latitude of grid 1:180 1:173 .. ..
SALT salinity 1:180 1:173 1:30 1:12 
AIRT air temperature 1:180 1:173 1:30 1:12
 
yes? ! For convenience define variables with curvilinear grid
 
yes? let lonin = geolon[d=1]
yes? let latin = geolat[d=1]
yes? ! Define output grid and a variable on the rectilinear output grid
 
yes? define axis/x=0:360:5/modulo/units=degrees xax
yes? def axis/y=0:85:5/units=degrees yax
 
! This is a dummy variable on the rectilinear grid
yes? let lonlatout = y[gy=yax] + x[gx=xax]
yes? ! Compute the mapping to the rectangular grid, save to a file
 
yes? let map = curv_to_rect_map ( lonin,latin,lonlatout,10)
yes? save/clobber/file=curv_map.nc map
yes? ! Apply the mapping to the data fields
 
yes? cancel var/all
yes? use curv_map.nc
yes? let out_salt = curv_to_rect(salt[d=1,K=1,L=2], map[d=2])yes? shade out_salt
yes? let out_airt = curv_to_rect(airt[d=1], map[d=2])
yes? save/file=air_on_rect.nc out_airt