Confused: Inconsistent result?

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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.
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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)
+ }
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]]

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and provide commented, minimal, self-contained, reproducible code.

Sorry, just checked it and you need to add ".GlobalEnv" to both ls() calls.

Michael

On Mon, Feb 20, 2012 at 10:17 AM, R. Michael Weylandt
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 as 
those
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
}
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______________________________________________
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.