title: R - Convert Date Time as character into Seconds (numeric)
body: <p>I am reading data time value from csv file stored as below</p>
  
  <pre><code>"2013-08-01 00:10:46"
  "2013-08-01 00:10:51"
  "2013-08-01 00:10:53"
  "2013-08-01 00:11:04"
  "2013-08-01 00:11:06"
  </code></pre>
  
  <p>While reading it is read as character and i want to convert it into seconds from 1970-01-01. I am able to achieve it using the below line of code but it takes ages to convert. Is there a better and faster way to achieve this</p>
  
  <pre><code>rstarttime  &lt;- as.numeric(as.POSIXct(rdata$starttime,origin = "1970-01-01"))
  </code></pre>