recenter documentation

The recenter function rewraps a gridded dataset to be centered on a specified longitude.

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Contents

Syntax

[lat,lon] = recenter(lat,lon)
[lat,lon,Z1,Z2,...,Zn] = recenter(lat,lon,Z1,Z2,...,Zn)
[...] = recenter(...,'center',centerLon)

Description

[lat,lon] = recenter(lat,lon) rewraps a global lat,lon grid such that it is centered on the Prime Meridian (zero longitude). A common application is to convert a grid spanning 0 to 360 into a grid spanning -180 to 180.

[lat,lon,Z1,Z2,...,Zn] = recenter(lat,lon,Z1,Z2,...,Zn) rewraps input grids lat,lon along with any other datasets Zn of corresponding dimensions. Any of the Z datasets can be 2D of exactly the same dimensions as lat and lon, or can be 3D, whose first two dimensions correspond to the lat,lon grids and the third dimension might correspond to time or depth.

[...] = recenter(...,'center',centerLon) centers gridded data on any specified longitude. Default centerlon is 0 degrees.

Example 1: Theoretical data points

Here's a 10 degree resolution grid with longitude values that go from 0 to 360, specified by setting the center longitude to 180 in cdtgrid:

[lat,lon] = cdtgrid(10,180);

plot(lon,lat,'bx')
xlabel 'longitude'
ylabel 'latitude'

Recenter the grid such that its midpoint lies at the Prime Meridian:

[lat2,lon2] = recenter(lat,lon);

hold on
plot(lon2,lat2,'ro')

Example 2: Application to sea surface temperature data

load global_sst.mat

% Convert lat,lon arrays to grid format:
[lon,lat] = meshgrid(lon,lat);

figure
imagescn(lon,lat,sst)
axis image
cmocean thermal

The grid is already centered on the Prime Meridian. But what if your research focuses on Hawaii? Then perhaps you'd like to center the map on 156 W:

[lat,lon,sst] = recenter(lat,lon,sst,'center',-156);

figure
imagescn(lon,lat,sst)
axis image
cmocean thermal

Author Info

This function is part of the Climate Data Toolbox for Matlab. The function and supporting documentation were written by Chad A. Greene of the University of Texas at Austin.