replace values in vector from a replacement table
try this:
(x <- rep(letters,2))
[1] "a" "b" "c" "d" "e" "f" "g" "h" "i" "j" "k" "l" "m" "n" "o" "p" "q" "r" "s" "t" "u" "v" "w" [24] "x" "y" "z" "a" "b" "c" "d" "e" "f" "g" "h" "i" "j" "k" "l" "m" "n" "o" "p" "q" "r" "s" "t" [47] "u" "v" "w" "x" "y" "z"
values <- c("aa", "a", "b", NA, "d", "zz")
repl <- c("aa", "A", "B", NA, "D", "zz")
(repl.tab <- cbind(values, repl))
values repl [1,] "aa" "aa" [2,] "a" "A" [3,] "b" "B" [4,] NA NA [5,] "d" "D" [6,] "zz" "zz"
indx <- match(x, repl.tab[, 1], nomatch = 0) x[indx != 0] <- repl.tab[indx, 2] x
[1] "A" "B" "c" "D" "e" "f" "g" "h" "i" "j" "k" "l" "m" "n" "o" "p" "q" "r" "s" "t" "u" "v" "w" [24] "x" "y" "z" "A" "B" "c" "D" "e" "f" "g" "h" "i" "j" "k" "l" "m" "n" "o" "p" "q" "r" "s" "t" [47] "u" "v" "w" "x" "y" "z"
On Mon, Jul 30, 2012 at 11:53 AM, Liviu Andronic <landronimirc at gmail.com> wrote:
Dear all I've got stuck when trying to replace values in a vector by selecting replacements from a replacement table. I'm trying to use only base functions. Here's a dummy example:
(x <- rep(letters,2))
[1] "a" "b" "c" "d" "e" "f" "g" "h" "i" "j" "k" "l" "m" "n" "o" "p" "q" "r" "s" "t" "u" "v" [23] "w" "x" "y" "z" "a" "b" "c" "d" "e" "f" "g" "h" "i" "j" "k" "l" "m" "n" "o" "p" "q" "r" [45] "s" "t" "u" "v" "w" "x" "y" "z"
values <- c("aa", "a", "b", NA, "d", "zz")
repl <- c("aa", "A", "B", NA, "D", "zz")
(repl.tab <- cbind(values, repl))
values repl [1,] "aa" "aa" [2,] "a" "A" [3,] "b" "B" [4,] NA NA [5,] "d" "D" [6,] "zz" "zz" Now I can easily compute all four combinations of 'match' and '%in%':
(ind <- match(x, repl.tab[ ,1]))
[1] 2 3 NA 5 NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA 2 3 NA [30] 5 NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA
(ind <- match(repl.tab[ ,1], x))
[1] NA 1 2 NA 4 NA
(ind <- x %in% repl.tab[ ,1])
[1] TRUE TRUE FALSE TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [15] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE TRUE TRUE [29] FALSE TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [43] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
(ind <- repl.tab[ ,1] %in% x)
[1] FALSE TRUE TRUE FALSE TRUE FALSE But how do I actually proceed to obtain the following vector? Can it be done without an explicit apply() or loop?
res
[1] "A" "B" "c" "D" "e" "f" "g" "h" "i" "j" "k" "l" "m" "n" "o" "p" "q" "r" "s" "t" "u" "v" [23] "w" "x" "y" "z" "A" "B" "c" "D" "e" "f" "g" "h" "i" "j" "k" "l" "m" "n" "o" "p" "q" "r" [45] "s" "t" "u" "v" "w" "x" "y" "z" Regards Liviu -- Do you know how to read? http://www.alienetworks.com/srtest.cfm http://goodies.xfce.org/projects/applications/xfce4-dict#speed-reader Do you know how to write? http://garbl.home.comcast.net/~garbl/stylemanual/e.htm#e-mail
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