raster combine
Combines rasters into all unique combinations of inputs
combine(x, rnames = NULL, sp = FALSE)
x |
raster stack/brick or SpatialPixelsDataFrame object |
rnames |
Column names to combine in raster stack or sp object |
sp |
(FALSE/TRUE) output SpatialPixelsDataFrame |
Please note that this is not a memory safe function that utilizes rasters out of memory in the manner that the raster package does.
If sp = TRUE the object will be a list with "combine", containing the SpatialPixelsDataFrame with the value attribute containing the unique combinations, and "summary" with the summary table of collapsed combinations and associated attributes.
If sp = FALSE the a single ratified rasterLayer class object is returned with the summary table as the raster attribute table, this is most similar to the ESRI format resulting from their combine function.
A ratified rasterLayer or a list containing a SpatialPixelsDataFrame and a data.frame of unique combinations.
Jeffrey S. Evans <jeffrey_evans@tnc.org>
library(raster)
r1 <- raster(nrows=100, ncol=100)
r1[] <- round(runif(ncell(r1), 1,4),0)
r2 <- raster(nrows=100, ncol=100)
r2[] <- round(runif(ncell(r2), 2,6),0)
r3 <- raster(nrows=100, ncol=100)
r3[] <- round(runif(ncell(r3), 2,6),0)
r <- stack(r1,r2,r3)
names(r) <- c("LC1","LC2","LC3")
# Combine rasters in stack
( cr <- combine(r) )
levels(cr)
# Combine rasters in stack, using specific rasters
( cr <- combine(r, rnames=c("LC1","LC3")) )
# Combine rasters in stack, output SpatialPixelsDataFrame
cr.sp <- combine(r, sp = TRUE)
head(cr.sp$summary)
class(cr.sp$combine)
# Input SpatialPixelsDataFrame
r.sp <- as(r, "SpatialPixelsDataFrame")
cr.sp <- combine(r.sp, sp = TRUE)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.