R.AlphA.Home (version 1.0.0)

importAll: Function to Import and Concatenate Multiple data files

Description

Imports multiple files into a list, concatenates them into a single table, and adds an `fName` variable.

The files can be selected either by giving a file list (character vector), or by specifying a pattern.

Usage

importAll(
  path = ".",
  pattern = "",
  ignore.case = FALSE,
  importFunction = NULL,
  fill = FALSE,
  fileList = NULL
)

Value

A data frame containing the concatenated table with the fName column

Arguments

path

Path to the directory, passed to `list.files`.

pattern

Pattern to match file names, passed to `list.files`.

ignore.case

Logical. If `TRUE`, ignores case when matching file names. Passed to `list.files`. Default behavior is case-sensitive (`FALSE`)

importFunction

A custom function for importing files. If not set, the function selects an import method based on the file extension.

fill

Logical. Passed to `rbind` to allow filling missing columns.

fileList

A character vector of file names to import (used instead of `pattern`).

Examples

# Directory containing test files
test_path <- tempdir()

# Create test files
write.csv( data.frame(a = 1:3, b = 4:6)    , file.path(test_path, "file1.csv"))
write.csv( data.frame(a = 7:9, b = 10:12)  , file.path(test_path, "file2.csv"))
write.csv( data.frame(a = 3:5, b = 8:10)   , file.path(test_path, "file3.csv"))
saveRDS(   data.frame(a = 1:5, b = 6:10)   , file.path(test_path, "file1.rds"))
saveRDS(   data.frame(a = 11:15, b = 16:20), file.path(test_path, "file2.rds"))

# Example 1 : Import all csv files
result <- importAll(path = test_path, pattern = "\\.csv$")
print(result)

# Example 2: Import only selected files
file_list <- c("file1.csv", "file2.csv")
result <- importAll(path = test_path, fileList = file_list)
print(result)

# Example 3: Import all .rds files
result <- importAll(path = test_path, pattern = "\\.rds$")
print(result)

# Example 4: Use a custom import function
custom_import <- function(file) {
  data <- read.csv(file, stringsAsFactors = FALSE)
  return(data)
}
result <- importAll(path = test_path, pattern = "\\.csv$", importFunction = custom_import)
print(result)