title: Find minimum non-zero value in a column R
body: <p>I have this situation in R:</p>
  
  <pre><code>my_minimum &lt;- min(my_data_frame[,my_column_number])
  </code></pre>
  
  <p>This returns the minimum value. What I want is the minimum non-zero value.
  I have seen a lot of more complicated situations where people want a vector of the non-zero minimum values but I simply want a single number, the lowest non-zero value that exists in</p>
  
  <pre><code>my_column_number
  </code></pre>
  
  <p>within </p>
  
  <pre><code>my_data_frame
  </code></pre>
  
  <p>For context, this is taking place within a for loop that iteratively plots some stuff for each column, and I need to get the non-zero minimum to add to the plot.</p>