gridded(obj)
gridded(obj) <- value
fullgrid(obj)
fullgrid(obj) <- value
gridparameters(obj)fullgrid returns a logical, telling whether the grid is full
and ordered (i.e., in full matrix form), or whether it is not full
or unordered (i.e. a list of points that happen to lie on a grid. If
assigned, the way the points are stored may be changed. Changing a set
of points to full matrix form and back may change the original order of
the points, and will remove duplicate points if they were present.gridparameters returns, if obj inherits from
SpatialGridDataFrame its grid parameters, else it returns numeric(0). The
returned value is a data.frame with three columns, named cellcentre.offset
("lower left cell centre coordinates"), cellsize, and cells.dim (cell
dimension); the rows correspond to the spatial dimensions.# just 9 points on a grid:
x <- c(1,1,1,2,2,2,3,3,3)
y <- c(1,2,3,1,2,3,1,2,3)
xy <- cbind(x,y)
S <- SpatialPoints(xy)
class(S)
plot(S)
gridded(S) <- TRUE
gridded(S)
class(S)
summary(S)
plot(S)
gridded(S) <- FALSE
gridded(S)
class(S)
# data.frame
data(meuse.grid)
coordinates(meuse.grid) <- ~x+y
gridded(meuse.grid) <- TRUE
plot(meuse.grid) # not much good
summary(meuse.grid)
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