asc2dataframe {SDMTools} | R Documentation |
asc2dataframe
converts a list of Esri ascii grid
formatted files to a data.frame consisting of only
locations with data.
dataframe2asc
converts a
data.frame or matrix with spatial data to Esri ascii grid
formatted files.
asc2dataframe(filenames, varnames = NULL, gz = FALSE) dataframe2asc(tdata, filenames = NULL, outdir = getwd(), gz = FALSE)
filenames |
is a vector of file names |
varnames |
is a vector of names for the output columns, and must be the same length as files |
tdata |
is the data.frame which has y, x coordinates (OR lat,lon) and columns for the data to be output (MUST be in that order) |
outdir |
is the output directory, the default is the current working directory |
gz |
boolean defining if the ascii grid files are gzip compressed |
asc2dataframe: The ascii grid files can be read in gzip compress format. The dataframe returned contains the X and Y coordinate columns followed by columns of data.
dataframe2asc: If filenames is null, column names will be used. The data.frame has to contain the Y and X coordinates and the data as columns. The ascii grid files can be created as gzip compress format and would be saved in the outdir.
asc2dataframe |
Returns a dataframe with XY coordinates and the data of each ascii grid files, as columns. |
dataframe2asc |
Returns an asc grid file for each data column within the data.frame. |
Lorena Falconi lorefalconi@gmail.com
#Create 2 ascii files y=seq(10,50,0.5) x=seq(140,180,0.5) cellsize=0.5 data1=sample(160,140) data2=sample(158,140) out1.asc=as.asc(matrix(data1,nc=y, nr=x), xll=min(x), yll=min(y), cellsize=cellsize) out2.asc=as.asc(matrix(data2,nc=y, nr=x), xll=min(x), yll=min(y), cellsize=cellsize) #write the ascii files to the work directory write.asc(out1.asc, 'out1.asc') write.asc(out2.asc, 'out2.asc') #list the ascii files ascfiles=c('out1.asc', 'out2.asc') #generate a dataframe from the ascii files tdata=asc2dataframe(ascfiles) tdata #remove the files unlink('out1.asc'); unlink('out2.asc') #convert the dataframe tdata to ascii grid files dataframe2asc(tdata) #remove the files unlink('var.1.asc'); unlink('var.2.asc')