[R] list indexing problem reading in files from a directory

Charles C. Berry cberry at tajo.ucsd.edu
Tue Aug 11 20:13:45 CEST 2009


On Tue, 11 Aug 2009, stephen sefick wrote:

> I am running into a problem with allocating these files to a list as
> they are read in through a for loop.  I know I am probably doing
> something wrong, but I can't figure out what.  I know this is not
> reproducible.  I am ending up with a data frame of the very last file
> to be read in.  I know it is in the indexing, but I can't wrap my head
> around it.
> thanks for all of the help,
>
> Stephen Sefick
>
>
>
> #level logger read in
> read.ll <- function(path){
> library(chron)
> library(zoo)
> list.of.files <- list.files(path)
> length.files <- length(list.of.files)
> 	for(i in 1:length.files){
> 	df <- list()

move the above line to BEFORE the loop and you should be good to go.

HTH,

Chuck

> 	df[[i]] <- read.table(paste(sep="/", path, list.of.files[i]), skip=45)
> 	length.1 <- length(df[[i]][,1])
> 	length.2 <- length(df[[i]][,1])-1
> 	df[[i]] <- df[[i]][-c(length.1, length.2),]
> 	df[[i]] <- data.frame(chron(as.character(df[[i]][,1]),
> as.character(df[[i]][,2]), format=c(dates="Y/m/d", times="H:M:S")),
> as.numeric(df[[i]][,3]), as.numeric(df[[i]][,4]),
> as.factor(list.of.files[[i]]))
>
> 	}
> }
>
> a <- read.ll("C:/Documents and Settings/Feminella
> Lab/Desktop/WB_LL_Data/Wolf Bay Data/Raw solinist data/Compensated by
> Brad")
>
> -- 
> Stephen Sefick
>
> Let's not spend our time and resources thinking about things that are
> so little or so large that all they really do for us is puff us up and
> make us feel like gods.  We are mammals, and have not exhausted the
> annoying little problems of being mammals.
>
> 								-K. Mullis
>
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>

Charles C. Berry                            (858) 534-2098
                                             Dept of Family/Preventive Medicine
E mailto:cberry at tajo.ucsd.edu	            UC San Diego
http://famprevmed.ucsd.edu/faculty/cberry/  La Jolla, San Diego 92093-0901




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