Hello All, I am trying to convert some points to a SpatialGridDataFrame and am running into difficulties. When I convert the SpatialPointsDataFrame into a gridded object, it gives many warning messages and the output is incorrect. It says that the cellsize is 500x500 which is incorrect, it is actually 50,000 by 50,000)
my.pts <- SpatialPointsDataFrame(coords=spatial.coords, data=my.df, proj4string=CRS(p4s)) gridded(my.pts) <- T Warning messages: 1: In points2grid(points, tolerance, round) : grid has empty column/rows in dimension 1 2: In points2grid(points, tolerance, round) : grid topology may be corrupt in dimension 1 3: In points2grid(points, tolerance, round) : grid has empty column/rows in dimension 2 4: In points2grid(points, tolerance, round) : grid topology may be corrupt in dimension 2 str(my.pts) Formal class 'SpatialPixelsDataFrame' [package "sp"] with 7 slots ..@ data :'data.frame': 35 obs. of 2 variables: .. ..$ X1: num [1:35] 140.5 84.2 66.3 74.7 98.2 ... .. ..$ X2: num [1:35] 155.8 73.9 57.4 72.6 88.4 ... ..@ coords.nrs : num(0) ..@ grid :Formal class 'GridTopology' [package "sp"] with 3 slots .. .. ..@ cellcentre.offset: Named num [1:2] -633000 -4422000 .. .. .. ..- attr(*, "names")= chr [1:2] "x" "y" .. .. ..@ cellsize : Named num [1:2] 500 500 .. .. .. ..- attr(*, "names")= chr [1:2] "x" "y" .. .. ..@ cells.dim : Named int [1:2] 503 902 .. .. .. ..- attr(*, "names")= chr [1:2] "x" "y" ..@ grid.index : int [1:35] 453405 453505 453605 453706 402904 403005 403105 403205 403305 403406 ... ..@ coords : num [1:35, 1:2] -532500 -482500 -432500 -382000 -633000 ... .. ..- attr(*, "dimnames")=List of 2 .. .. ..$ : NULL .. .. ..$ : chr [1:2] "x" "y" ..@ bbox : num [1:2, 1:2] -633250 -4422250 -381750 -3971250 .. ..- attr(*, "dimnames")=List of 2 .. .. ..$ : chr [1:2] "x" "y" .. .. ..$ : chr [1:2] "min" "max" ..@ proj4string:Formal class 'CRS' [package "sp"] with 1 slots .. .. ..@ projargs: chr " +proj=stere +lat_0=90 +lat_ts=60 +lon_0=-110 +k=1 +x_0=0 +y_0=0 +ellps=GRS80 +datum=NAD83 +units=m +no_defs +towgs84=0,0,0" I have also tried to build the GridTopology & glue it together with my data: gtop.coords.min <- c(min(spatial.coords[,1]), min(spatial.coords[,2])) gtop.coords.max <- c(max(my.coords[,1]), max(my.coords[,2])) gtop.cell.size <- c(50000, 50000) gtop.cells.dim.xc <- length(seq(gtop.coords.min[1], gtop.coords.max[1], by=gtop.cell.size[1])) gtop.cells.dim.yc <- length(seq(gtop.coords.min[2], gtop.coords.max[2], by=gtop.cell.size[2])) gtop.cells.dim <- c(gtop.cells.dim.xc, gtop.cells.dim.yc) cangrid.gtop <- GridTopology(gtop.coords.min, gtop.cell.size, gtop.cells.dim) str(cangrid.gtop) Formal class 'GridTopology' [package "sp"] with 3 slots ..@ cellcentre.offset: num [1:2] -633000 -4422000 ..@ cellsize : num [1:2] 50000 50000 ..@ cells.dim : int [1:2] 6 10 SpatialGridDataFrame(grid=cangrid.gtop, data=my.df, proj4string=CRS(p4s)) Error in validityMethod(object) : unequal number of objects in full grid and data slot I have included an image of what the coordinates look like and included a shapefile of the coordinates. Here is a description of my variables: p4s "+proj=stere +lat_0=90 +lat_ts=60 +lon_0=-110 +k=1 +x_0=0 +y_0=0 +ellps=GRS80 +datum=NAD83 +units=m +no_defs" spatial.coords x y 1 -532500 -4422000 2 -482500 -4422000 3 -432500 -4422000 4 -382000 -4422000 5 -633000 -4372000 6 -582500 -4372000 7 -532500 -4372000 8 -482500 -4372000 9 -432500 -4372000 10 -382000 -4372000 11 -583000 -4322000 12 -532500 -4322000 13 -482500 -4322000 14 -432500 -4322000 15 -382000 -4322000 16 -583000 -4272000 17 -532500 -4272000 18 -482500 -4272000 19 -432500 -4272000 20 -382000 -4272000 21 -583000 -4222000 22 -532500 -4222000 23 -482500 -4222000 24 -432500 -4222000 25 -583000 -4172000 26 -532500 -4172000 27 -482500 -4172000 28 -583000 -4122000 29 -532500 -4122000 30 -482500 -4122000 31 -633000 -4071500 32 -583000 -4072000 33 -532500 -4072000 34 -583000 -4021500 35 -633000 -3971500 str(my.df) 'data.frame': 35 obs. of 2 variables: $ X1: num 140.5 84.2 66.3 74.7 98.2 ... $ X2: num 155.8 73.9 57.4 72.6 88.4 ... Many thanks, Hailey
spatial_coords.dbf
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spatial_coords.prj
Description: Binary data
spatial_coords.shp
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spatial_coords.shx
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<<attachment: points_to_sgdf.JPG>>
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