title: Saving text into multiple files
body: <p>How can I save the output data at each loop with the following filenames: "file01.txt", "file02.txt", ..
  ?<br>
  Here is the example of my R code:</p>
  
  <pre><code>data &lt;- matrix(c(59, 50, 48, 62, 44, 34, 78, 59, 42, 67, 51, 45, 72, 64, 52), 
                   byrow=TRUE, ncol=3)
  u &lt;- c(33, 46, 53)
  for (i in 1:length(u)){
             data[data&lt;u[i]] &lt;- NA  
             data &lt;- data
             print(data)
  }
             [,1] [,2] [,3]
        [1,]   59   50   48
        [2,]   62   44   34
        [3,]   78   59   42
        [4,]   67   51   45
        [5,]   72   64   52
             [,1] [,2] [,3]
        [1,]   59   50   48
        [2,]   62   NA   NA
        [3,]   78   59   NA
        [4,]   67   51   NA
        [5,]   72   64   52
             [,1] [,2] [,3]
        [1,]   59   NA   NA
        [2,]   62   NA   NA
        [3,]   78   59   NA
        [4,]   67   NA   NA
        [5,]   72   64   NA
  </code></pre>