R help - Nov 2010 - Function not working

Below is the (really basic) script I am creating to call a function that
sets the working directory, determines the number of files it will need to
process in that directory, and creates a mask.  A "for" loop will
eventually
be added that will loop through the files (arrays) in that directory
performing a baseline/zero correction and apply the mask - that will
probably be a later plea for help. It is being designed for a specific
idiot-proof purpose (obviously it found an idiot) which is why you just have
to input the directory.

This function was working fine on my x64 2.12.0 build of R on my home
computer, but when I brought to work and started fiddling with the script on
my x32 2.12.0 it didn't work. It sources without a problem, and I can call
it without getting an error message, but all it seems willing to do is set
the working directory.  Entering "n", "mat" or
"mask" after that to make
sure it ran results in "Error: object 'mat' not found."  I
have copied and
pasted the text into a new script, tried it with "\\" and with
"/". Rebooted
R, sourced from the command line and from the menu...  None of the functions
I am using are exclusive to x64 or a package (that I know of).  I need to
know why it was working on one computer and not the other because, in final
form, it will be transported and used on different systems by people with
minimal understanding of R.

The call would look something like: EEMCORR("C:\\Documents and
Settings\\User\\Desktop\\folder\\subfolder") or wherever they put the data
arrays.

EEMCORR <- function(location){

#set working directory, find number of files in directory
setwd(location)
n <- (length(list.files(getwd())))-1

#mask
mat<-matrix(0, 20,20)
mat[upper.tri(mat)]<-"ZZ"
mask<- rbind((cbind(matrix(0,20,20),mat)),matrix(0,100,40))
}

Thanks for your keen eyes

Thomas

	[[alternative HTML version deleted]]

On 01/11/2010 12:56 PM, Thomas Parr wrote:
> Below is the (really basic) script I am creating to call a function that
> sets the working directory, determines the number of files it will need to
> process in that directory, and creates a mask.  A "for" loop will
eventually
> be added that will loop through the files (arrays) in that directory
> performing a baseline/zero correction and apply the mask - that will
> probably be a later plea for help. It is being designed for a specific
> idiot-proof purpose (obviously it found an idiot) which is why you just
have
> to input the directory.
>
> This function was working fine on my x64 2.12.0 build of R on my home
> computer, but when I brought to work and started fiddling with the script
on
> my x32 2.12.0 it didn't work. It sources without a problem, and I can
call
> it without getting an error message, but all it seems willing to do is set
> the working directory.  Entering "n", "mat" or
"mask" after that to make
> sure it ran results in "Error: object 'mat' not found." 
I have copied and
> pasted the text into a new script, tried it with "\\" and with
"/". Rebooted
> R, sourced from the command line and from the menu...  None of the
functions
> I am using are exclusive to x64 or a package (that I know of).  I need to
> know why it was working on one computer and not the other because, in final
> form, it will be transported and used on different systems by people with
> minimal understanding of R.
I think it wasn't working on your x64 computer, but you happened to have 
existing variables named n, mat and mask, and you mistakenly thought 
your function was setting them.

> The call would look something like: EEMCORR("C:\\Documents and
> Settings\\User\\Desktop\\folder\\subfolder") or wherever they put the
data
> arrays.
>
> EEMCORR<- function(location){
>
> #set working directory, find number of files in directory
> setwd(location)
> n<- (length(list.files(getwd())))-1
>
> #mask
> mat<-matrix(0, 20,20)
> mat[upper.tri(mat)]<-"ZZ"
> mask<- rbind((cbind(matrix(0,20,20),mat)),matrix(0,100,40))
> }
>
This function has local variables n, mat and mask, but never changes the 
values of global ones.  Generally functions that have such global side 
effects are a bad idea, but if you are sure you want to do it, use n <<- 
..., mat <<- ..., etc.  The <<- "superassignment" operator
makes the
assignment in a parent or global environment.

Duncan Murdoch
> Thanks for your keen eyes
>
> Thomas
>
> 	[[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.