Hello, after the creation of a data.frame I like to add NAs as follows:
n <- 743;
x <- runif(n, 1, 7);
Y <- runif(n, 1, 7);
Ag6 <- runif(n, 1, 7);
df <- data.frame(x, Y, Ag6);
# a list with positions:
v <- apply(df, 2, function(x) sample(n, sample(1:ceiling(5*n/100), 1),
repl=F));
# a loop too much?
for (i in 1:length(df)){
df[unlist(v[i]), i] <- NA;
}
summary(df);
This works fine but it appears to me that there is a more elegant and simple way
-- which one?
Thanks
S?ren
Try this: df <- as.data.frame(mapply(`[<-`, x = df, i = v, NA)) On Sat, May 8, 2010 at 12:12 PM, <soeren.vogel@eawag.ch> wrote:> Hello, after the creation of a data.frame I like to add NAs as follows: > > n <- 743; > x <- runif(n, 1, 7); > Y <- runif(n, 1, 7); > Ag6 <- runif(n, 1, 7); > df <- data.frame(x, Y, Ag6); > # a list with positions: > v <- apply(df, 2, function(x) sample(n, sample(1:ceiling(5*n/100), 1), > repl=F)); > # a loop too much? > for (i in 1:length(df)){ > df[unlist(v[i]), i] <- NA; > } > summary(df); > > This works fine but it appears to me that there is a more elegant and > simple way -- which one? > > Thanks > Sören > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. >-- Henrique Dallazuanna Curitiba-Paraná-Brasil 25° 25' 40" S 49° 16' 22" O [[alternative HTML version deleted]]
That seems to be a suitable situation for a loop although you might wish to write it like this: for ( nm in names(df) ) df[ v[[nm]], nm ] <- NA Note that R does not require semicolons at the end of each statement. On Sat, May 8, 2010 at 11:12 AM, <soeren.vogel at eawag.ch> wrote:> Hello, after the creation of a data.frame I like to add NAs as follows: > > n <- 743; > x <- runif(n, 1, 7); > Y <- runif(n, 1, 7); > Ag6 <- runif(n, 1, 7); > df <- data.frame(x, Y, Ag6); > # a list with positions: > v <- apply(df, 2, function(x) sample(n, sample(1:ceiling(5*n/100), 1), repl=F)); > # a loop too much? > for (i in 1:length(df)){ > ?df[unlist(v[i]), i] <- NA; > } > summary(df); > > This works fine but it appears to me that there is a more elegant and simple way -- which one? > > Thanks > S?ren > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. >