Assignment to variables fails to loop

listOfNames <- c("a", "b", "c")
listOfVariables <- c("vara", "varb", "varc")

for(index in seq_along(listOfNames)){

	print(index) # integer sweeping the two lists
	print(paste("assigning variable", listOfNames[index], "to ",  
listOfVariables[index]))
	assign(listOfNames[index], listOfVariables[index])

}


# or more succinctly
mapply(assign, x=listOfNames, value=listOfVariables)

Dear all,

I think I'm nearly there in writing R code which will read in files  
with two variable parts to the file name and then assigning these  
file names to objects, which also have two variable parts. I have  
got the code running without encountering errors, however, I receive  
50+ of the same warnings:

1: In assign(paste("Fekete_", index$year, index$month, sep =  
""),  ... :
 only the first element is used as variable name

And it's true, when I do ls() only Fekete198601 has been assigned.  
I've attempted to rectify this, but have only come up against  
further errors.

The code as it stands, is as follows:


# READ IN FILES FROM DISK

# File names have two variable parts: creating a 'file index' is a  
two-step process

index <- expand.grid(year = sprintf("%04d", seq(1986, 1995)), month  
= sprintf("%02d", 1:12))
filelist <- paste("C:\\Documents and Settings\\Data\ 
\comp_runoff_hd_", paste(index$year, index$month, sep=''), '.asc',  
sep='')

filelist


# Assign file names to individual objects with variable name  
components

for (i in filelist) {
         assign(paste("Fekete_",index$year, index$month,  
sep=''),read.table(file=i, header=FALSE, sep=" "))


         update <- substr(i,35,55) # substring - 2nd argument is  
character at which extraction is to begin, 3rd argument is where  
extraction ends.
         print(c("LOADED FILE:",update), quote=FALSE)
         }

ls()

[1] "Fekete_198601" "filelist"      "i"             "index"
[5] "update"


Why is it that only Fekete_198601 has had data assigned to it (there  
should be 120 such objects in total) and how do I go about solving  
this?


Many thanks again for any help offered,


Steve

Dear all,

I think I'm nearly there in writing R code which will read in files with two variable parts to the file name and then assigning these file names to objects, which also have two variable parts. I have got the code running without encountering errors, however, I receive 50+ of the same warnings:

1: In assign(paste("Fekete_", index$year, index$month, sep = ""), ?... :
?only the first element is used as variable name

And it's true, when I do ls() only Fekete198601 has been assigned. I've attempted to rectify this, but have only come up against further errors.

The code as it stands, is as follows:


# READ IN FILES FROM DISK

# File names have two variable parts: creating a 'file index' is a two-step process

index <- expand.grid(year = sprintf("%04d", seq(1986, 1995)), month = sprintf("%02d", 1:12))
filelist <- paste("C:\\Documents and Settings\\Data\\comp_runoff_hd_", paste(index$year, index$month, sep=''), '.asc', sep='')

filelist


# Assign file names to individual objects with variable name components

for (i in filelist) {
? ? ? ? ?assign(paste("Fekete_",index$year, index$month, sep=''),read.table(file=i, header=FALSE, sep=" "))


? ? ? ? ?update <- substr(i,35,55) # substring - 2nd argument is character at which extraction is to begin, 3rd argument is where extraction ends.
? ? ? ? ?print(c("LOADED FILE:",update), quote=FALSE)
? ? ? ? ?}

ls()

[1] "Fekete_198601" "filelist" ? ? ?"i" ? ? ? ? ? ? "index"
[5] "update"


Why is it that only Fekete_198601 has had data assigned to it (there should be 120 such objects in total) and how do I go about solving this?


Many thanks again for any help offered,


Steve