title: read.table reads numbers as factors
body: <p>I have the following sample file:</p>
  
  <pre><code>"id";"PCA0";"PCA1";"PCA2"
  1;6.142741644872954;1.2075898020608253;1.8946959360032403   
  2;-0.5329026419681557;-8.586870627925729;4.510113575138726
  </code></pre>
  
  <p>When I try to read it with:</p>
  
  <pre><code>d &lt;- read.table("file.csv", sep=";", header=T)
  </code></pre>
  
  <p><code>id</code> is a integer column, <code>PCA0</code> a numeric an all subsequent columns are factors</p>
  
  <pre><code>class(d$iid)
  [1] "integer"
  class(d$PCA0)
  [1] "numeric"
  class(d$PCA1)
  [1] "factor"
  class(d$PCA2)
  [1] "factor"
  </code></pre>
  
  <p>Why aren't the other columns numeric as well? </p>
  
  <p>I know how to convert the columns, but I want my script to work without manually casting the types. Why doesn't R recognize the numeric columns?</p>