define spatial grid with attribute data

defines spatial grid by offset, cell size and dimensions

SpatialPixelsDataFrame(points, data, tolerance = sqrt(.Machine$double.eps), 
    proj4string = CRS(as.character(NA)), round = NULL, grid = NULL)
SpatialGridDataFrame(grid, data, proj4string = CRS(as.character(NA)))

Arguments

points

coordinates, either as numeric matrix or as object of class SpatialPoints-class

grid

grid topology; object of class GridTopology-class; for calls to SpatialPixelsDataFrame a value of NULL implies that this will be derived from the point coordinates

data

data.frame; contains the attribute (actual grid) data

tolerance

precision up to which extent points should be exactly on a grid

round

default NULL, otherwise a value passed to as the digits argument to round for setting cell size

proj4string

object of class CRS-class in the first form only used when points does not inherit from Spatial-class

Value

SpatialPixelsDataFrame returns an object of class SpatialPixelsDataFrame-class; SpatialGridDataFrame returns an object of class SpatialGridDataFrame-class.

Note

SpatialPixels stores grid topology and coordinates of the actual points, which may be in the form of a subset (set of pixels) of a full grid. To find out or change this, see fullgrid and SpatialGrid-class.

Author

Edzer Pebesma

See also

gridded, gridded<-, SpatialGrid, SpatialGrid-class

Examples

data(meuse.grid)
m = SpatialPixelsDataFrame(points = meuse.grid[c("x", "y")], data = meuse.grid)
class(m)
#> [1] "SpatialPixelsDataFrame"
#> attr(,"package")
#> [1] "sp"
summary(m)
#> Object of class SpatialPixelsDataFrame
#> Coordinates:
#>      min    max
#> x 178440 181560
#> y 329600 333760
#> Is projected: NA 
#> proj4string : [NA]
#> Number of points: 3103
#> Grid attributes:
#>   cellcentre.offset cellsize cells.dim
#> x            178460       40        78
#> y            329620       40       104
#> Data attributes:
#>        x                y              part.a           part.b      
#>  Min.   :178460   Min.   :329620   Min.   :0.0000   Min.   :0.0000  
#>  1st Qu.:179420   1st Qu.:330460   1st Qu.:0.0000   1st Qu.:0.0000  
#>  Median :179980   Median :331220   Median :0.0000   Median :1.0000  
#>  Mean   :179985   Mean   :331348   Mean   :0.3986   Mean   :0.6014  
#>  3rd Qu.:180580   3rd Qu.:332140   3rd Qu.:1.0000   3rd Qu.:1.0000  
#>  Max.   :181540   Max.   :333740   Max.   :1.0000   Max.   :1.0000  
#>       dist        soil     ffreq   
#>  Min.   :0.0000   1:1665   1: 779  
#>  1st Qu.:0.1193   2:1084   2:1335  
#>  Median :0.2715   3: 354   3: 989  
#>  Mean   :0.2971                    
#>  3rd Qu.:0.4402                    
#>  Max.   :0.9926