title: How to handle "NA" in Julia
body: <p>I need to hadle a file with missing values ("NA") in Julia.<br>
  The command that I'm using to read the file is:   </p>
  
  <p><code>file = readdlm("FILE_NAs.txt", header=false)</code></p>
  
  <p>The problem is that I can't use this files in math equations (like matrix multiplication) because the "NA"s.<br>
  I tried to use the package "DataArray" and the function "dropna(file)", but did not work.<br>
  So, I'd like to ignore or even remove those "NA"s values.</p>
  
  <p>Here is a sample of the loaded file (space delimited):</p>
  
  <pre><code>"Ind1" "NA"  "NA"  "NA"   "NA"   "NA"   "NA"  2   "NA"   "NA"
  "Ind2" "NA"  "NA"  "NA"   "NA"   "NA"   "NA"  2   "NA"   "NA"
  "Ind3" "NA"  "NA"  "NA"   "NA"   "NA"   "NA"  1   "NA"   "NA"
  "Ind4" "NA"  "NA"  "NA"   "NA"   "NA"   "NA"  2   "NA"   "NA"
  "Ind5" 0     0     0      0      0      0     1   0      0 
  "Ind6" 1     0     0      0      1      1     2   1      1 
  "Ind7" 1     0     0      0      1      1     2   1      1 
  "Ind8" 0     0     0      0      0      0     2   0      0
  </code></pre>