title: How do you convert a char data frame to numeric?
body: <p>In order to continue with my preparation of the dataset, I need to make it so the str of each col is numeric instead of chars.</p>
  <pre><code>str(eighthr)
  'data.frame':   2533 obs. of  74 variables:
   $ Date  : chr  &quot;1/2/1998&quot; &quot;1/3/1998&quot; &quot;1/4/1998&quot; &quot;1/5/1998&quot; ...
   $ WSR0  : chr  &quot;2.8&quot; &quot;2.9&quot; &quot;4.7&quot; &quot;2.6&quot; ...
   $ WSR1  : chr  &quot;3.2&quot; &quot;2.8&quot; &quot;3.8&quot; &quot;2.1&quot; ...
   $ WSR2  : chr  &quot;3.3&quot; &quot;2.6&quot; &quot;3.7&quot; &quot;1.6&quot; ...
   $ WSR3  : chr  &quot;2.7&quot; &quot;2.1&quot; &quot;3.8&quot; &quot;1.4&quot; ...
   $ WSR4  : chr  &quot;3.3&quot; &quot;2.2&quot; &quot;2.9&quot; &quot;0.9&quot; ...
   $ WSR5  : chr  &quot;3.2&quot; &quot;2.5&quot; &quot;3.1&quot; &quot;1.5&quot; ...
  </code></pre>
  <p>How do I convert all rows except $Date?</p>