On Jun 19, 2014, at 12:08 PM, efridge wrote: > Hello, > > Firstly, real new to R here. > > I have a function intended to evaluate the values in columns spread over > many tables. I have an argument in the function that allows the user to > input what sequence of tables they want to draw data from. The function > seems to work fine, but when the user inputs a single number (over 9) > instead of a sequence using the : operator, I find an error message: > > the input for this example is 30 > > Error in file(file, "rt") : cannot open the connection > > 5 file(file, "rt") > > 4 read.table(file = file, header = header, sep = sep, quote = quote, dec = > dec, fill = fill, comment.char = comment.char, ...) > > 3 FUN("specdata/3e+01.csv"[[1L]], ...) > > 2 lapply(filepaths, read.csv) > > 1 pollutantmean("specdata", "nitrate", 30) > > In addition: Warning message: > > In file(file, "rt") : cannot open file 'specdata/3e+01.csv': No such file or > directory > > *The problem is that when a single number (30, 104, 223) is input, it's > being stored as 3e+01 and no longer corresponds with the .csv file I'm > trying to call (030.csv).* > > Below is my code: > > pollutantmean <- function(directory, pollutant, id = 1:332){ > filenames <- paste0(formatC(id, digits = 0, width = 3, flag = "0"), ".csv") > filepaths <- file.path(directory, filenames) > list_of_data_frames <- lapply(filepaths, read.csv) > big.df<-do.call(rbind,list_of_data_frames) > print(str(big.df)) > mean(big.df[,pollutant], na.rm=TRUE) > } > > I'm curious if formatC() is converting the number to scientific notation or > is that the default for R if there is no sequence when there could be.
I think it's your `digits = 0` argument: > formatC(20, digits = 3, width = 3, flag = "0") [1] "020" > > Many of you probably recognize this as a coursera assignment. It's beyond > the due date and I've submitted some (pretty not good) code for it. I just > want to have a good understanding of what's going on here, as this type of > work is directly related to my research. > > -- David Winsemius Alameda, CA, USA ______________________________________________ R-help@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.