setGridOrder {gmGeostats}

Set or get the ordering of a grid

Description

Specify or retrieve the ordering in which a grid is stored in a vector (or matrix).

Usage

setGridOrder(x, refpoint, cycle)

setGridOrder_sp(x, G = 2)

setGridOrder_array(x, G = 2)

gridOrder_sp(G = 2)

gridOrder_gstat(G = 2)

gridOrder_array(G = 2)

gridOrder_GSLib(G = 2)

Arguments

x

a data container for the elements of the grid; the grid order is stored as an attribute to it

refpoint

a string specifying which point of the grid corresponds to the first element of x; see below

cycle

a permutation of the integers 1:G (see below)

G

number of geographic dimensions of the setting, typically G=2 or G=3

Details

A "gridOrder" attribute is a list consisting of two named elements:

refpoint

one of "topleft", "bottomleft", "topright" or "bottomright" in 2D, or also of "topleftsurf", "bottomleftsurf", "toprightsurf", "bottomrightsurf", "topleftdeep","bottomleftdeep", "toprightdeep" or "bottomrightdeep" in 3D ("deep" is accessory, i.e. "topleft"== "topleftdeep"), indicating the location on the grid of the first point of the object x

cycle

a permutation of 1:G indicating in which order run the dymensions, from faster to slower

Thus, a conventional ordering of a (nX*nY)-element vector into a matrix to plot with graphics::image() corresponds to an refpoint="bottomleft" and cycle=1:2, i.e. start with the lower left corner and run first by rows (eastwards), then by columns (northwards). This is constructed by gridOrder_array(G), and can be directly set to an object x by setGridOrder_array(x,G); gridOrder_GSLib is an alias for gridOrder_array.

The grids from package "sp" (and many other in R), on the contrary follow the convention refpoint="topleft" and cycle=1:2, i.e. start with the upper left corner and run first by rows (eastwards), then by columns (southwards). This is constructed by gridOrder_sp(G), and can be directly set to an object x by setGridOrder_sp(x,G); gridOrder_gstat is an alias for gridOrder_sp.

Value

setGridOrder(x,...) returns the object x with the grid order description attached as an attribute "gridOrder"; getGridOrder(x) retrieves this attribute and returns it.

Functions

• setGridOrder_sp: Set or get the ordering of a grid

• setGridOrder_array: Set or get the ordering of a grid

• gridOrder_sp: Set or get the ordering of a grid

• gridOrder_gstat: Set or get the ordering of a grid

• gridOrder_array: Set or get the ordering of a grid

• gridOrder_GSLib: Set or get the ordering of a grid

See Also

sortDataInGrid() for ways of reordering a grid

Examples

gt = sp::GridTopology(cellcentre.offset=c(1,11), cellsize=c(1,1), cells.dim=c(5,3))
sp::coordinates(sp::SpatialGrid(grid=gt))
gridOrder_sp(2)