Use arg. file

#43

vignettes/read_txt_PerkinElmer.R

@@ -3,7 +3,7 @@
 
 #' Read PerkinElmer file (ASCII/txt)
 #'
-#' @param files Path to file.
+#' @param file Path to file or several files
 #' @param ... Passed to [base::scan()].
 #' @param label Labels.
 #'
@@ -13,7 +13,7 @@
 #'
 #' @export
 #'
-read_txt_PerkinElmer <- function(files = stop("filenames needed"),
+read_txt_PerkinElmer <- function(file = stop("filenames needed"),
                                  ...,
                                  label = list()) {
 
@@ -27,31 +27,31 @@ read_txt_PerkinElmer <- function(files = stop("filenames needed"),
     label
   )
 
-  if (length(files) == 0) {
+  if (length(file) == 0) {
     warning("No files found.")
     return(new("hyperSpec"))
   }
 
   ## read the first file
-  buffer <- matrix(scan(files[1], ...), ncol = 2, byrow = TRUE)
+  buffer <- matrix(scan(file[1], ...), ncol = 2, byrow = TRUE)
 
   ## first column gives the wavelength vector
   wavelength <- buffer[, 1]
 
   ## preallocate the spectra matrix:
   ##  one row per file x as many columns as the first file has
-  spc <- matrix(ncol = nrow(buffer), nrow = length(files))
+  spc <- matrix(ncol = nrow(buffer), nrow = length(file))
 
   ## the first file's data goes into the first row
   spc[1, ] <- buffer[, 2]
 
   ## now read the remaining files
-  for (f in seq(along = files)[-1]) {
-    buffer <- matrix(scan(files[f], ...), ncol = 2, byrow = TRUE)
+  for (f in seq(along = file)[-1]) {
+    buffer <- matrix(scan(file[f], ...), ncol = 2, byrow = TRUE)
 
     ## check whether they have the same wavelength axis
     if (!all.equal(buffer[, 1], wavelength)) {
-      stop(paste(files[f], "has different wavelength axis."))
+      stop(paste(file[f], "has different wavelength axis."))
     }
 
     spc[f, ] <- buffer[, 2]
@@ -61,7 +61,7 @@ read_txt_PerkinElmer <- function(files = stop("filenames needed"),
   spc <- new("hyperSpec", wavelength = wavelength, spc = spc, label = label)
 
   ## consistent file import behavior across import functions
-  .spc_io_postprocess_optional(spc, files)
+  .spc_io_postprocess_optional(spc, file)
 }