This is copy & paste from my session:> xyz<-as.vector(c(ls(),as.matrix(lapply(ls(),class)))) > dim(xyz)<-c(length(xyz)/2,2) > > allobj<-function(){+ xyz<-as.vector(c(ls(),as.matrix(lapply(ls(),class)))); + dim(xyz)<-c(length(xyz)/2,2); + return(xyz) + }> xyz[,1] [,2] [1,] "a" "character" [2,] "aa" "character" [3,] "abc" "character" [4,] "AirPassengers" "character" [5,] "allobj" "character" [6,] "allObjects" "character" [7,] "allObjects2" "character" [8,] "arrayFromAPL" "character" [9,] "classes" "character" [10,] "myCharVector" "character" [11,] "myDateVector" "character" [12,] "myNumericVector" "character" [13,] "newArrayFromAPL" "character" [14,] "obj" "character" [15,] "objClass" "character" [16,] "x" "character" [17,] "xyz" "character" [18,] "y" "character"> allobj()[,1] [,2]>As far as I can see, the function allobj has the same expressions as those executed from the command line. Why are the results different? [[alternative HTML version deleted]]
On Feb 20, 2012, at 10:07 AM, Ajay Askoolum wrote:> This is copy & paste from my session: > >> xyz<-as.vector(c(ls(),as.matrix(lapply(ls(),class)))) >> dim(xyz)<-c(length(xyz)/2,2) >> >> allobj<-function(){ > + xyz<-as.vector(c(ls(),as.matrix(lapply(ls(),class)))); > + dim(xyz)<-c(length(xyz)/2,2); > + return(xyz) > + } >> xyz > [,1] [,2] > [1,] "a" "character" > [2,] "aa" "character" > [3,] "abc" "character" > [4,] "AirPassengers" "character" > [5,] "allobj" "character" > [6,] "allObjects" "character" > [7,] "allObjects2" "character" > [8,] "arrayFromAPL" "character" > [9,] "classes" "character" > [10,] "myCharVector" "character" > [11,] "myDateVector" "character" > [12,] "myNumericVector" "character" > [13,] "newArrayFromAPL" "character" > [14,] "obj" "character" > [15,] "objClass" "character" > [16,] "x" "character" > [17,] "xyz" "character" > [18,] "y" "character" >> allobj() > [,1] [,2] >> > > As far as I can see, the function allobj has the same expressions as > those executed from the command line. Why are the results different?The ls function looks only in the local environment if not supplied with specific directions about where to look.> [[alternative HTML version deleted]] > > ______________________________________________ > 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.David Winsemius, MD West Hartford, CT
Short answer, environments -- ls() looks (by default) in its current environment, which is not the same as the global environment when being called inside a function. This would (I think) give the same answer but I haven't checked it. :> allobj<-function(){+ xyz<-as.vector(c(ls(.GlobalEnv),as.matrix(lapply(ls(),class)))); + dim(xyz)<-c(length(xyz)/2,2); + return(xyz) + } On Mon, Feb 20, 2012 at 10:07 AM, Ajay Askoolum <aa2e72e at yahoo.co.uk> wrote:> This is copy & paste from my session: > >> xyz<-as.vector(c(ls(),as.matrix(lapply(ls(),class)))) >> dim(xyz)<-c(length(xyz)/2,2) >> >> allobj<-function(){ > + xyz<-as.vector(c(ls(),as.matrix(lapply(ls(),class)))); > + dim(xyz)<-c(length(xyz)/2,2); > + return(xyz) > + } >> xyz > ????? [,1]????????????? [,2] > ?[1,] "a"?????????????? "character" > ?[2,] "aa"????????????? "character" > ?[3,] "abc"???????????? "character" > ?[4,] "AirPassengers"?? "character" > ?[5,] "allobj"????????? "character" > ?[6,] "allObjects"????? "character" > ?[7,] "allObjects2"???? "character" > ?[8,] "arrayFromAPL"??? "character" > ?[9,] "classes"???????? "character" > [10,] "myCharVector"??? "character" > [11,] "myDateVector"??? "character" > [12,] "myNumericVector" "character" > [13,] "newArrayFromAPL" "character" > [14,] "obj"???????????? "character" > [15,] "objClass"??????? "character" > [16,] "x"?????????????? "character" > [17,] "xyz"???????????? "character" > [18,] "y"?????????????? "character" >> allobj() > ???? [,1] [,2] >> > > As far as I can see, the function allobj has the same expressions as those executed from the command line. Why are the results different? > ? ? ? ?[[alternative HTML version deleted]] > > > ______________________________________________ > 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. >
Hi> > This is copy & paste from my session: > > > xyz<-as.vector(c(ls(),as.matrix(lapply(ls(),class)))) > > dim(xyz)<-c(length(xyz)/2,2) > > > > allobj<-function(){ > + xyz<-as.vector(c(ls(),as.matrix(lapply(ls(),class)))); > + dim(xyz)<-c(length(xyz)/2,2); > + return(xyz) > + } > > xyz > [,1] [,2] > [1,] "a" "character" > [2,] "aa" "character" > [3,] "abc" "character" > [4,] "AirPassengers" "character" > [5,] "allobj" "character" > [6,] "allObjects" "character" > [7,] "allObjects2" "character" > [8,] "arrayFromAPL" "character" > [9,] "classes" "character" > [10,] "myCharVector" "character" > [11,] "myDateVector" "character" > [12,] "myNumericVector" "character" > [13,] "newArrayFromAPL" "character" > [14,] "obj" "character" > [15,] "objClass" "character" > [16,] "x" "character" > [17,] "xyz" "character" > [18,] "y" "character" > > allobj() > [,1] [,2] > > > > As far as I can see, the function allobj has the same expressions asthose> executed from the command line. Why are the results different?Probably due to environment handling. Do you really want to check if ls behaves as is intended and that it produces character vector? Or your intention is a little bit more ambitious and you want to know what objects do you have? If the later, I recommend to use this function: function (pos = 1, pattern, order.by) { napply <- function(names, fn) sapply(names, function(x) fn(get(x, pos = pos))) names <- ls(pos = pos, pattern = pattern) obj.class <- napply(names, function(x) as.character(class(x))[1]) obj.mode <- napply(names, mode) obj.type <- ifelse(is.na(obj.class), obj.mode, obj.class) obj.size <- napply(names, object.size) obj.dim <- t(napply(names, function(x) as.numeric(dim(x))[1:2])) vec <- is.na(obj.dim)[, 1] & (obj.type != "function") obj.dim[vec, 1] <- napply(names, length)[vec] out <- data.frame(obj.type, obj.size, obj.dim) names(out) <- c("Type", "Size", "Rows", "Columns") if (!missing(order.by)) out <- out[order(out[[order.by]]), ] out }> [[alternative HTML version deleted]] > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guidehttp://www.R-project.org/posting-guide.html> and provide commented, minimal, self-contained, reproducible code.