Show Memory Usage
DESCRIPTION:
Returns a list describing the storage allocated by S-PLUS.
USAGE: 
storage()
VALUE:
list describing the current internal storage allocated by S-PLUS. The four components are:
allocated:
size (in bytes) of each allocated arena.
used:
number of bytes used in each arena.
location:
starting memory address for the arena.
frame:
frame number (function call) associated with each arena.
headers:
number of headers put to use since creation of bucket.
freed:
number of headers in bucket used but now free to use again.
frame:
frame number associated with each bucket.
DETAILS:
Internal storage in S-PLUS is allocated in arenas (currently 4088 bytes) which are then divided to satisfy memory requests. Not all of an arena will be used up by current requests. Each arena is associated with one of the frames (function calls) currently being evaluated. Storage requests that would occupy more than half of a standard arena are given a separate individual arena.

Each data vector consists of a 32 byte "header" and storage for the data. The headers for a given frame are allocated in "buckets" consisting of 500 (on DOS 75) headers and 20 bytes of housekeeping information for a total size of 16020 bytes (on DOS 2420) per bucket. (These sizes may not be quite right on some machines: they depend on how the C compiler chooses to pad structures and on the size of pointer and integer types.)

The first four components of the value of storage give the allocated and used size, the actual location in memory, and the associated frame number for each storage arena. The next three components give the number of headers ever allocated (since the creation of the bucket), the number allocated then freed, and the associated frame number for each bucket of headers.

SEE ALSO:
allocated , memory.size , object.size .
EXAMPLES: 
# barplot (from a function) of local arenas
temp <- storage()
barplot(temp$allocated[temp$frame == sys.nframe()])


barplot(rbind(temp$used[1:22], temp$all[1:22]), blocks=F, density=c(20, 0),
     angle=c(45, 0), names=as.character(temp$frame[1:22]),
     main="Arena Allocation and Use", xlab="frame")