Question

I have 2 datasets:

Data1:

Var1 Var2   Var3    Var4
10    10      2   3
9      2      8   3
6      4      4   8
7      3     10   8

Data2:

Var1 Var5   Var3    Var6
  3    6      6   4
  1    2      5   1
  9    2      2   9
  2    6      3   2

Now I want to append this 2 datasets

Final Data:

Var1  Var2    Var3  Var4  Var5 Var6
10      10       2     3        
9        2       8     3        
6        4       4     8        
7        3      10     8        
3                      4     6    6
1                      1     2    5
9                      9     2    2
2                      2     6    3

I can’t use rbind to create this dataset. Can anybody please tell me the method to create this dataset? Also, suppose I want to append multiple (more than 2) datasets. What’s the procedure?

Answer 1

# Open a new directory and keep only the data files to be combined
combinedfiles <- function(){
  # nullVar: Creating a Null Variable using as.null function
    nullVar <- function(x){ 
    x <- getwd(); 
    x <- as.null(x); 
    }

  # readTab: Read file using read.table function
    readTab <- function(y) { 
    read.table(y, header=TRUE, sep = " ") 
    }

    objectcontent <- nullVar(x);    

    for (i in 1:length(list.files(getwd()))) {
    y <- list.files(getwd())[i];
    objectcontent <- rbind(objectcontent, readTab(y));
    i <- i + 1
    }
  return(objectcontent)
}

#Then type the following in the console
  combinedfiles()

a version using apply loops (which do not suffer from the rbind slowdown):

combined_files = function(file_path, extension = "csv") {
   require(plyr)
   file_list = list.files(file_path, pattern = extension)
   data_list = lapply(file_list, read.table, header = TRUE, sep = " ")
   combined_data = do.call("rbind.fill", data_list)
   return(combined_data)
 }