You can do: lapply2(u, v, function(u,v) u[inRange(u, range(v))])
using two functions 'lapply2' and 'inRange' defined at bottom. This basically does: lapply(seq(along=u), function(i, U, V){ u <- U[[i]] v <- V[[i]] u[u >= range(v)[1] & u <= range(v)[2]] }, U = u, V = v) Tim Hesterberg >I want to apply this function to the columns of a data frame: > >u[u >= range(v)[1] & u <= range(v)[2]] > >where u is the n column data frame under consideration and v is a data frame >of values with the same number of columns as u. For example, >v1 <- c(1,2,3) >v2 <- c(3,4,5) >v3 <- c(2,3,4) >v <- as.data.frame(cbind(v1,v2,v3)) > >uk1 <- seq(min(v1) - .5, max(v1) + .5, .5) >uk2 <- seq(min(v2) - .5, max(v2) + .5, .5) >uk3 <- seq(min(v3) - .5, max(v3) + .5, .5) > >u <- do.call("expand.grid", list(uk1,uk2,uk3)) > >Here, there are 3 columns; instead of hard-coding this, can the function >given above, which will restrict the u data frame to values within the >ranges of each variable, be done with the apply function? Thanks in >advance. > >dxc13 # inRange requires ifelse1, part of the "splus2R" package. inRange <- function(x, a, b, strict = FALSE) { # Return TRUE where x is within the range of a to b. # If a is length 2 and b is missing, assume that a gives the range. # if(strict==FALSE), then allow equality, otherwise require a < x < b. # strict may be a vector of length 2, governing the two ends. if(length(a)==2) { b <- a[2] a <- a[1] } else if(length(a) * length(b) != 1) stop("a and b must both have length 1, or a may have length 2") strict <- rep(strict, length=2) ifelse1(strict[1], x>a, x>=a) & ifelse1(strict[2], x<b, x<=b) } lapply2 <- function(X1, X2, FUN, ...){ # Like lapply, but for two inputs. # FUN should take two inputs, one from X1 and one from X2. n1 <- length(X1) if(n1 != length(X2)) stop("X1 and X2 have different lengths") if(is.character(FUN)) FUN <- getFunction(FUN) else if(!is.function(FUN)) { farg <- substitute(FUN) if(is.name(farg)) FUN <- getFunction(farg) else stop("'", deparseText(farg), "' is not a function") } FUNi <- function(i, X1, X2, FUN2, ...) FUN2(X1[[i]], X2[[i]], ...) # Create sequence vector. # If objects have same names, use them. i <- seq(length = n1) names1 <- names(X1) if(length(names1) && identical(names1, names(X2))) names(i) <- names1 # Final result; loop over the sequence vector lapply(i, FUNi, X1 = X1, X2 = X2, FUN2 = FUN, ...) } ______________________________________________ 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.