title: import multiple txt files into R
body: <p>I am working with MODIS 8-day data and am trying to import all the txt files of one MODIS product into the R, but not as one single data.frame, as individual txt files. So I can later apply same functions on them. The main objective is to export specific elements within each txt file. I was successful in excluding the desired elements from one txt file with the following command:</p>
  
  <pre><code># selecting the element within the table
  idxs &lt;- gsub("\\]",")", gsub("\\[", "c(",  "[24,175], [47,977], [159,520], [163,530]
                               ,[165,721], [168,56], [217,820],[243,397],[252,991],[284,277],[292,673]
                               ,[322,775], [369,832], [396,872], [434,986],[521,563],[522,717],[604,554]
                               ,[608,50],[614,69],[752,213],[780,535],[786,898],[788,1008],[853,1159],[1014,785],[1078,1070]") )
  
  lst &lt;- rbind( c(24,175), c(47,977), c(159,520), c(163,530) ,c(165,721), c(168,56), c(217,820),c(243,397),c(252,991),c(284,277),c(292,673),c(322,775), c(369,832), c(396,872), c(434,986),c(521,563),c(522,717),c(604,554),c(608,50),c(614,69),c(752,213),c(780,535),c(786,898),c(788,1008),c(853,1159),c(1014,785),c(1078,1070))
  
  mat &lt;-  matrix(scan("lst.txt",skip = 6),nrow=1200)
  
  Clist &lt;- as.data.frame(mat[lst])
  </code></pre>
  
  <p>But I need these element from all of the txt files and honestly I do not want to run it manually for 871 times. So I try to read all the txt files and then apply this function to them. but unfortunately it does not work. here is my approach:</p>
  
  <pre><code>folder &lt;- "C:/Users/Documents/R/MODIS/txt/"      
  txt_files &lt;- list.files(path=folder, pattern=".txt")
  
  df= c(rep(data.frame(), length(txt_files)))
  
  for(i in 1:length(txt_files)) {df[[i]]&lt;- as.list(read.table(txt_files[i]))}
  </code></pre>
  
  <p>and this is the error I encounter:</p>
  
  <pre><code>**Error in file(file, "rt") : cannot open the connection
  In addition: Warning message:
    In file(file, "rt") :
    cannot open file 'rastert_a2001361.txt': No such file or directory**
  </code></pre>
  
  <p>additional information: each txt file includes 1200rows and 1200columns and 20-30 elements need to be extracted from the table. </p>
  
  <p>I am very much looking forward for your answers and appreciate any helps or recommendations with this matter. </p>