Hi Dylan, On Sun, Aug 16, 2009 at 8:02 PM, Dylan Beaudette<[email protected]> wrote: > Hi Markus, > > Can you sample the original maps with v.random + v.what.rast first?
This gave me the idea: spsample() - I just read page 118 in "Applied spatial data analysis with R" (great book, http://www.asdar-book.org/ !). But apparently I am missing something... (I am certainly reading too fast): # Spearfish example > mydata <- readRAST6(c("elevation.dem","soils")) > subdata <- spsample(mydata, 500, type= "random") Looks good but... > str(subdata) Formal class 'SpatialPoints' [package "sp"] with 3 slots ..@ coords : num [1:497, 1:2] 600572 596804 599446 597732 600336 ... .. ..- attr(*, "dimnames")=List of 2 .. .. ..$ : NULL .. .. ..$ : chr [1:2] "x" "y" ..@ bbox : num [1:2, 1:2] 590022 4914167 608953 4927981 .. ..- 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=utm +zone=13 +a=6378206.4 +rf=294.9786982 +no_defs +nadgrids=/home/neteler/grass65/dist.x86_64-unknown-linux-gnu/etc/nad"| __truncated__ ... where are the data? The original looks like: > str(mydata) Formal class 'SpatialGridDataFrame' [package "sp"] with 6 slots ..@ data :'data.frame': 2654802 obs. of 2 variables: .. ..$ elevation.dem: int [1:2654802] NA NA NA NA NA NA NA NA NA NA ... .. ..$ soils : int [1:2654802] NA NA NA NA NA NA NA NA NA NA ... ..@ grid :Formal class 'GridTopology' [package "sp"] with 3 slots .. .. ..@ cellcentre.offset: Named num [1:2] 590015 4914025 .. .. .. ..- attr(*, "names")= chr [1:2] "x" "y" .. .. ..@ cellsize : num [1:2] 10 10 .. .. ..@ cells.dim : int [1:2] 1899 1398 ..@ grid.index : int(0) ..@ coords : num [1:2, 1:2] 590015 608995 4914025 4927995 .. ..- attr(*, "dimnames")=List of 2 .. .. ..$ : NULL .. .. ..$ : chr [1:2] "x" "y" ..@ bbox : num [1:2, 1:2] 590010 4914020 609000 4928000 .. ..- 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=utm +zone=13 +a=6378206.4 +rf=294.9786982 +no_defs +nadgrids=/home/neteler/grass65/dist.x86_64-unknown-linux-gnu/etc/nad"| __truncated__ According to showMethods("spsample") grids are supported... I guess I am missing a trivial bit, might be the time here... thanks Markus _______________________________________________ grass-stats mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-stats
