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Value Matching
Syntax
match(x, table, nomatch=NA)
Arguments
x
|
the values to be matched.
|
table
|
the values to be matched against.
|
nomatch
|
the value to be returned in the case when no match is found.
|
Description
If x[i]
is found to equal table[j]
then the value returned in the i
-th position of the return value is
j
.
If no match is found, the value is nomatch
.
See Also
pmatch
for partial string matching.
Examples
"%in%" <- function(a, b) !is.na(match(a, b))#- following John Wallace
1:10 %in% c(1,3,5,9)
sstr <- c("c","ab","B","bba","c","@","bla","a","Ba","%")
sstr[sstr %in% c(letters,LETTERS)]
## The intersection of two sets :
intersect <- function(x, y) y[match(x, y, nomatch = 0)]
intersect(1:10,7:20)