title: adding the same calculation with a difference but not changing TRUE/FALSE standard using r data table package
body: <p>i have a dataset with 3 columns of interest: price_mid,quantity and value mid. the way to find price_mid is value/quanity. but some times you might have to multiply it by either a factor of 10 or 100.
  now i have 3 potential formula's to bear in mind. I created a variable called valid to tell TRUE/FALSE as to weather the price_mid is equal to value/quantity *100 how could i simply extend this using data table package.</p>
  
  <pre><code>#This is the code i'm using.
  dt[,valid := price_mid == (value_mid/quantity)*100]
  </code></pre>
  
  <p>how could i accomadate the 2 others without replacing the standard for TRUE/FALSE.</p>
  
  <p>Thanks.</p>