Importing many files at the same time and adding ID indicator

Question

I have 91 files - .log format:

rajectory Log File

Rock type: 2 (0: Sphere, 1: Cuboid, 2: Rock)

Nr of Trajectories: 91
Trajectory-Mode: ON
Average Slope (D         


        

Answer 1

You could also check out purrr::map_df which behaves like lapply or for loop but returns a data.frame

read_traj <- function(fi) {
    df <- read.table(fi, header=F, skip=23)
    df <- df[, c(1:4, 15)]
    colnames(df) <- c("t", "x", "y", "z", "Etot")
    return(df)
}

files.list <- list.files(pattern = ".log")
library(tidyverse)

map_df has a handy feature .id=... that creates a column, id, with numbers 1...N where N is number of files.

map_df(files.list, ~read_traj(.x), .id="id")

If you want to save the file name instead, use the id column to access files.list

map_df(files.list, ~read_traj(.x), .id="id") %>%
  mutate(id = files.list[as.numeric(id)])