[R] DEM calculation
Lars Claussen
LarsVegas at nikocity.de
Thu Jun 2 10:56:13 CEST 2005
Hello R-World,
i am trying to calculate data for a DEM (Digital Elavation Model) which i
also want to plot in R. i have the coordinates for the lower left corner
which look something like this:
x<-42,2
y<-50,5
besides i have the cellsize of the grid, which is:
z<-1,1
what i do is to calculate the corrdinates of the cells to the right and top,
what i can do by specifying the number of rows and columns. these are
j<-1:805 (columns)
i<-1:616 (rows)
well, to calculate them seperatly is easy:
r<-x+(i-1)*z
h<-y+(j-1)*z
but i can't get it straight how to create a data frame with two rows, one
for the x- the other for the y-coordinate. The problem is, that lots of
values have to be repeated as every first row x-coordinate has the same
y-coordinate and so on.
finally it should look like this:
x y
42,2 50,5
43,3 50,5
44,4 50,5
45,5 50,5
. .
. .
42,2 51,5
43,3 51,5
44,3 51,5
any suggestion? thanks in advance, Lars Claussen
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