Thanks, couldn't find this function, Best regards
Bart ----- Original Message ----- From: "Gabor Grothendieck" <[EMAIL PROTECTED]> To: "Bart Joosen" <[EMAIL PROTECTED]> Cc: <[email protected]> Sent: Saturday, June 24, 2006 1:15 PM Subject: Re: [R] data frame search > Try this: > > which(DF1 == 4, arr.ind = TRUE) > > > On 6/24/06, Bart Joosen <[EMAIL PROTECTED]> wrote: >> Hi, >> >> I want to make a data frame which contains the positions of some searched >> values in another data frame. >> >> Like: >> Dataframe 1: >> >> 1 2 3 4 1 2 3 4 >> 2 3 4 1 2 3 4 2 >> 4 1 2 3 2 3 4 1 >> >> Let's say I searched on "4", then Dataframe 2 should contain: >> x y >> 1 4 >> 1 8 >> 2 3 >> 2 7 >> 3 1 >> 3 7 >> >> I have written a routine, but it seems to me that it isn't that perfect: >> x<- 0 >> >> y<- 0 >> >> for (j in 1:ncol(df)) { >> >> for (i in 1:nrow(df)) { >> >> if (df[i,j] == 3) { >> >> x <- c(x,i) >> >> y <- c(y,j) >> >> } >> >> } >> >> } >> >> df2 <- data.frame(x,y) >> >> df2 <- df2[-1,] >> >> Can someone come up with an elegant/faster solution, because the ultimate >> goal of this routine is to analyze an jpg image. >> >> Kind regards >> >> Bart > ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
