Hi, list:

I would like to get all the bioclimatic variables of future scenarios for
species distribution modelling, so I run the "biovars" function in "dismo"
packages using the three variables from worldclim database, and I got a
RasterBrick of 12 layers:


 >prec<-stack(paste(getwd(),"/prec_2080/wc_2_5m_HADCM3_B2a_2080_prec_",1:12,".bil",sep=""))

 >tmin<-stack(paste(getwd(),"/tmin_2080/wc_2_5m_HADCM3_B2a_2080_tmin_",1:12,".bil",sep=""))

 >tmax<-stack(paste(getwd(),"/tmax_2080/wc_2_5m_HADCM3_B2a_2080_tmax_",1:12,".bil",sep=""))
    >x<-biovars(prec=prec,tmin=tmin,tmax=tmax)
    > x
    class       : RasterBrick
    dimensions  : 3600, 8640, 12  (nrow, ncol, nlayers)
    resolution  : 0.04166667, 0.04166667  (x, y)
    extent      : -180, 180, -60, 90  (xmin, xmax, ymin, ymax)
    projection  : NA
    values      :
C:/DOCUME~1/Marco/LOCALS~1/TMP/R_raster_tmp/raster_tmp_8984740455.grd
    min values  :     42 -65458  -1017      0     71      0 -65439     22
  23     56 ...
    max values  :  65456    213      1  34159  65534  65513  65534  65507
 65503  65518 ...

However, I thought there should be 19 bioclim variables. As you mentioned
that there are more arguments in biovars except the there, but I do not know
what they are. Could you help me out?

Another problem of this is that I got error writing these variables:

    >writeRaster(x,paste(getwd(),"/wc_2_5m_HADCM3_B2a_2080_1.grd",sep=""))
    Error in dim(res) <- c(ncols, raster@data@nlayers * nrows) :
      dims [product 933120] do not match the length of object [889920]

and, when I tried to write them band by band, I got the following error:

    >for (i in 10:12) {

 >writeRaster(x[[i]],paste(getwd(),"/wc_2_5m_HADCM3_B2a_2080_",i,".grd",sep=""),overwrite=TRUE)
                          }
    Error in result[, i] <- readBin(raster@file@con, what = dtype, n =
ncols,  :
      replacement has length zero

The three input variables have the same dimensions, e.g.:

    > prec
    class       : RasterStack
    dimensions  : 3600, 8640, 12  (nrow, ncol, nlayers)
    resolution  : 0.04166667, 0.04166667  (x, y)
    extent      : -180, 180, -60, 90  (xmin, xmax, ymin, ymax)
    projection  : NA
    min values  : 0 0 0 0 0 0 0 0 0 0 ...
    max values  : 65535 65535 65535 65535 65535 65535 65535 65535 65535
65535 ...

Could anybody explain why? Thanks in advance~


Marco

-------------------------------------------------------
Ph.D candidate,
Chinese Ecological Research Network,
Institute of Geographical Sciences and Natural Resources Research,
 Chinese Academy of Sciences,
100101, Beijing
Tel: (86)-10-6488 9809

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