[R-sig-eco] adehabitat: Number of categories of each habitat

[Roy Sanderson]

Hello

Apologies for asking such a simple question, but I have been having
problems obtaining a simple summary of the habitat classes in a
categorical (factor) asc map in the adehabitat library.  It has been
created from overlaying an mcp polygon as follows:

# Importation of asc files: factor e.g vegetation map
(vegm <- paste("Y:/Map Import/veg05_7.asc", sep = "/")) # veg05_7 is a vegetation map with 10 classes
(vegt <- paste("Y:/Map Import/veg05_2.txt", sep = "/")) # veg05 is a table with the names of the 10 classes
veg <- import.asc(vegm, lev = vegt, type = "factor")

# A Script to compute Homerange using Minimum Concex Polygon(MCP)
roans<-read.csv("Y:/PhD Data/Data Analysis/Roan Data Analysis/Rawdata/NTO_G.csv") # Load the data
xy<-roans[,c("X","Y")] # combine columns X & Y into a new column labelled xy
id<-roans$Group # Allocate label id to Group column
hrtg<-mcp(xy,id,percent=95) # Compute the homerange MCP

## Converts the home range to raster
hrrast <- hr.rast(hrtg, veg)

## for each relocation, finds the values of the variables in x
mcpveg = setmask(veg, hrrast)
hrrast2 = getkasc(hrrast, "Nyatoto Group")
mcpveg = setmask(veg, hrrast2)

The asc map, mcpveg, produced by the final setmask function contains
just the vegetation types within the MCP.  This map displays correctly.
However, I'm unclear on how to obtain a numerical summary of the number
of cells of each vegetation type, or percentage of each vegetation type,
within the
MCP.  Typing:

summary(mcpveg)

gives hundreds of columns, relating to the geographic structure of the
asc map.

Many thanks for your advice
Roy

-- 
Roy Sanderson,
Institute for Research on Environment and Sustainability (IRES),
Devonshire Building,
Newcastle University,
Newcastle upon Tyne NE1 7RU
r.a.sanderson at newcastle.ac.uk
0191 246 4835