Merge spatial data in R : a Rasterlayer and a SpatialPointsDataFrame

Question

I want to merge two objects, ie combining values attributes in one single table. My objects are one RasterLayer and a SpatialPointsDataFrame, that does not have the same resolution nor the same coordinates. But both have the same CRS.

class(z)
"RasterLayer"
attr(,"package")
[1] "raster"
class(occ_all)
[1] "SpatialPointsDataFrame"
attr(,"package")
[1] "sp"

> head(coordinates(z),4)
         x        y
[1,] -10.91667 71.91667
[2,] -10.75000 71.91667
[3,] -10.58333 71.91667
[4,] -10.41667 71.91667

> head(occ_all)
  Lon    Lat EuroVegMap Euforgen Gbif
1 -10.417 52.083          0        0    0
2 -10.250 51.917          0        0    0
3 -10.250 52.083          0        0    0
4 -10.250 52.250          0        0    0
5 -10.083 51.750          0        0    0

So, I wanted to use over() function but this doesn't work :

over(z,occ_all)
Error in (function (classes, fdef, mtable)  : 
unable to find an inherited method for function ‘over’ for signature ‘"RasterLayer","SpatialPointsDataFrame"’

Function extract() seems to work, but I don't exactly know how it works and I am not sure this takes into account corresponding coordinates.

So, I thought about using a nearest neighbours function (knn) to be sure that links between coordinates are correctly assigned. any idea for this method?

Could you please give me any advices to "simply" merge my two spatial objects ?

Thanks

Please provide a simple reproducible example, like this or this (for example). — Josh O'Brien

Paco Barreras Paco Barreras · Accepted Answer · 2015-04-13T21:25:12

It depends on the type of object you want the merging of the two objects to be. You could use the command rasterize() of the class {Raster}, to create a raster object from your spatialPolygons object that matches the resolution and origin of your rasterLayer. Let me know if this helps.

Merge spatial data in R : a Rasterlayer and a SpatialPointsDataFrame

1 Answers