[R] replace text in table R?

[Sarah Goslee]

Thanks for the complete reproducible example.

Here's one way to approach the problem; there are many others.

recodeDat <- function(x, invals, outvals) {
x <- as.character(x)
invals <- as.character(invals)
outvals <- as.character(outvals)
# a loop is the most understandable approach
for(i in seq_along(invals)) {
x[x == invals[i]] <- outvals[i]
}
# I would change the zeros to NA values
x[x == "0"] <- NA

factor(x, levels=sort(unique(outvals)))
}

dat1.recode <- dat1
dat1.recode[, 3:ncol(dat1.recode)] <- apply(dat1.recode[,
3:ncol(dat1.recode)], 2, recodeDat, invals=dat2[,1], outvals=dat2[,2])

On Tue, Mar 8, 2016 at 4:26 PM, Marna Wagley <marna.wagley at gmail.com> wrote:
> Hi R Users,
> I have been struggling to replace texts in a table by new text. but it
> seems crazy as of I am doing it manually in R. I have very big files and
> some of the text has to be replaced by another class based on another file
> if the name corresponds. I was able to perform following example but it
> should be easier if there is a loop. Any suggestions on making a loop for
> this example?
>
> Here is the example how I did. I want to assign class into dat1 based on
> dat2 table.
>
> dat1<-structure(list(ID = structure(1:8, .Label = c("X127", "X128",
> "X129", "X130", "X131", "X132", "X133", "X134"), class = "factor"),
>     Name = structure(1:8, .Label = c("Site1", "Site2", "Site3",
>     "Site4", "Site5", "Site6", "Site7", "Site8"), class = "factor"),
>     Time1 = structure(c(4L, 2L, 3L, 5L, 1L, 1L, 4L, 5L), .Label = c("0",
>     "GT", "R", "Tr", "W2"), class = "factor"), Time2 = structure(c(2L,
>     1L, 4L, 2L, 1L, 3L, 4L, 1L), .Label = c("0", "GT", "MA",
>     "UA"), class = "factor"), Time3 = structure(c(5L, 1L, 4L,
>     4L, 2L, 3L, 3L, 1L), .Label = c("0", "GT", "R", "Tr", "Y7"
>     ), class = "factor")), .Names = c("ID", "Name", "Time1",
> "Time2", "Time3"), class = "data.frame", row.names = c(NA, -8L
> ))
>
> dat1
>
> dat2<-structure(list(site = structure(c(4L, 2L, 5L, 3L, 6L, 7L, 8L,
> 1L), .Label = c("GT", "MA", "R", "Tr", "UA", "W1", "W2", "Y7"
> ), class = "factor"), To.be.assinged = structure(c(1L, 2L, 3L,
> 1L, 4L, 4L, 1L, 2L), .Label = c("A", "B", "C", "D"), class = "factor")),
> .Names = c("site",
> "To.be.assinged"), class = "data.frame", row.names = c(NA, -8L
> ))
> dat2
>
> A2 <- as.data.frame(lapply(dat1,function(x)
> if(is.character(x)|is.factor(x)) gsub("Tr","A",x) else x))
> A3 <- as.data.frame(lapply(A2,function(x) if(is.character(x)|is.factor(x))
> gsub("MA","B",x) else x))
> A4 <- as.data.frame(lapply(A3,function(x) if(is.character(x)|is.factor(x))
> gsub("UA","C",x) else x))
> A5 <- as.data.frame(lapply(A4,function(x) if(is.character(x)|is.factor(x))
> gsub("R","A",x) else x))
> A6 <- as.data.frame(lapply(A5,function(x) if(is.character(x)|is.factor(x))
> gsub("W1","D",x) else x))
> A7 <- as.data.frame(lapply(A6,function(x) if(is.character(x)|is.factor(x))
> gsub("W2","D",x) else x))
> A8 <- as.data.frame(lapply(A7,function(x) if(is.character(x)|is.factor(x))
> gsub("Y7","A",x) else x))
> A9 <- as.data.frame(lapply(A8,function(x) if(is.character(x)|is.factor(x))
> gsub("GT","B",x) else x))
> A9
>
> Your help is highly appreciated.
> Thanks
>

-- 
Sarah Goslee
http://www.functionaldiversity.org