Median
DESCRIPTION:
Returns a number which is the median of the data. Missing values can be removed before the computation.
USAGE: 
median(x, na.rm = F)
REQUIRED ARGUMENTS:
x:
numeric object.
Missing values (NA) are allowed.
OPTIONAL ARGUMENTS:
na.rm:
logical flag: should missing values be removed before computation?
VALUE:
median of the data.
DETAILS:
If x contains any NAs, the result will be NA unless na.rm=TRUE.
NOTE:
For long vectors using quantile(x, .5) rather than median(x) will be significantly faster since quantile uses a partial sort while median uses a sort. However, quantile uses single precision.
SEE ALSO:
apply , mad , mean , quantile , robloc , testscores .
EXAMPLES: 
algebra <- testscores[,3] # create sample object of algebra testscores
median(algebra) # median of scores


apply(testscores, 2, median) # vector of the medians of the columns
                             # in testscores data set