title: Find frequency of each column in data.frame
body: <p>I have a data.frame as below, and i would like to find the frequency for each column.</p>
  
  <p>data.frame ;</p>
  
  <pre><code>No      Location     Age         Size         Gender
  1        Trinidad     25          3              1
  2        Asin         33          2              2
  3        Trinidad     33          5              2
  4        Trinidad     23          3              1
  5        Asin         25          5              1
  6        Asin         23          2              2
  7        Trinidad     23          4              2
  </code></pre>
  
  <p>Desired output</p>
  
  <pre><code>Location    Loc_Freq  
  Trinidad       4
  Asin           3  
  
  Age   Age_Freq     
  23       3
  25       2
  33       2
  
  Size    Size_Freq  
  2          2
  3          2
  4          1
  5          2   
  
  Gender    Gender_Freq
   1            3
   2            4
  </code></pre>
  
  <p>Can anyone help? Thank you ahead.</p>