title: How to make the long numbers not shown scientific mode in data.table in R?
body: <p>I have several .csv files in a folder. I want to read them all once by using the command</p>
  
  <pre><code>library(data.table)
  path &lt;-path
  list &lt;-  list.files(path,pattern="*.csv")
  files &lt;- paste(path,list,sep='/')
  DT &lt;- do.call(rbind, lapply(files, fread))
  </code></pre>
  
  <p>However, since the first column is a 12 digits number, data.table shows it in a scientific number way, like</p>
  
  <pre><code>5.43971221673e-313
  </code></pre>
  
  <p>How should I convert all the scientific numbers into normal integers?</p>
  
  <p>Thanks a lot!</p>
  
  <p>First edit:
  After I use the command</p>
  
  <pre><code>options("scipen"=100, "digits"=12)
  </code></pre>
  
  <p>It still shows the number like </p>
  
  <pre><code>5.43971221673e-313
  </code></pre>
  
  <p>Even after I applied the command</p>
  
  <pre><code>options(scipen=999)
  </code></pre>
  
  <p>It gives me back the number</p>
  
  <pre><code>0.000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000543971221673
  </code></pre>
  
  <p>And even 543971221673 is not the correct number, the correct one should be</p>
  
  <pre><code>110101001001
  </code></pre>
  
  <p>I was using data.frame to try to convert, it works.</p>
  
  <pre><code>a &lt;- read.csv(files)
  a[,1] &lt;- as.character(a[,1])
  </code></pre>
  
  <p>But I would prefer to use data.table to make it fast. </p>
  
  <p>Thank you guys!</p>