Hi all,
I have some concerns regarding the rasterize option in R and I would like to
know if the fun=max in rasterize in R provides similar results to the one
achieved by using "Polygon to Raster using maximum-combined-area" in ArcGIS?
I'm trying to rasterize a habitat layer to a raster of 10m spatial resolution
using the function 'max' (e.g. r <- rasterize(ht, r, "Priority", fun = 'max')
and I would like to assign the habitat of the largest overlapping area, which
is similar to the “maximum-combined-area”. My original layer contains the
habitat information as a character string values (e.g. K1, K2, I1, I2, I3,
etc.) of 20 classes. Before resterizing, I have converted these classes to
numeric (e.g. in my case 1 to 20).
I have my doubts about the validity and type of maximums generated by this
code. From what I can see, I’m not sure if the use of fun= ‘max’ in Rasterize
in R implies the use of the absolute maximum or the combined maximum area. My
point is if I convert the original character string values of Priority to
numeric, the maximum for the numeric values will have nothing to do with the
maximum combined area under cover. For example, if we have a pixel which is
covered by 90% of habitat 1 and 10% of habitat 15, the value of the pixel will
be assigned to the habitat 15. Does that make any sense? Any suggestion or
clarification would be appreciated.Regards
Ashraf,
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