I need a faster way of doing this instead of using for loops in R [closed]

Question

So what I'm trying to do is add a column of 0's to this data frame, but if any of the rows has the code "h353" within any of the columns in that row, then I want that row to have a 1 instead of a 0 in the new column. I'm not even sure if the code works as is, but I just know it's going to take forever to run in its current state since the file is pretty large. Any suggestions on how to fix this/make it more efficient?

current code

Answer 1

This should do the job:

dat<-data.frame(x=rep(0,30), y=rep(0,30), z=rep(0,30))
dat[2,2]<-"h353"
dat[15,3]<-"h353"
dat[20,1]<-"h353"


dat$md<-0

for (i in 1:length(dat[1,])) {if (i==1){mdrows<-as.character(dat[,i])=="h353"} else {mdrows<-mdrows|as.character(dat[,i])=="h353"}}

dat$md[mdrows]<-1