Defining subdomains

These functions may be used to define subdomains (i.e. a rectangular subset of grid points) of any geofield domain.

Usage

subgrid(geo, x1, x2, y1, y2, reso = 1) 
zoomgrid(geo, x, y, zoom = 50)

Arguments

geo

A geofield or geodomain object.

x1,y1

Matrix index of the SW corner of the subdomain.

x2,y2

Matrix index of the NE corner of the subdomain.

reso

Resolution of the subdomain. It may be any positive integer. If reso is an integer larger than 1, the resolution is dropped by taking only a subset of points with interval reso. Default is 1 (all gridpoints are kept).

x,y

Matrix index of the central point of a 'zoomed' grid.

zoom

The number of matrix points at either side of the central point of the subgrid.

Value

A geofield object with a regular subset of the grid. If the input is a geodomain, then the result is too.

Details

zoomgrid is in fact just a wrapper for a particular type of call to subgrid, which is a bit more general. Note that there is no interpolation of any kind involved in these routines. It is simply a subselection of grid boxes. This could also be interpreted as a version of regrid(...,method="closest").

See also

regrid