title: Filter by column values while reading using read.csv in R
body: <p>I have a huge dataset in the form of a txt file with values separated by semi colons and has close to 2M rows. I need data only corresponding to particular dates in the first col. Sample input is shown below:</p>
  
  <pre><code>Date;Time;Global_active_power;Global_reactive_power;Voltage;Global_intensity;Sub_metering_1;Sub_metering_2;Sub_metering_3
  16/12/2006;17:24:00;4.216;0.418;234.840;18.400;0.000;1.000;17.000
  16/12/2006;17:25:00;5.360;0.436;233.630;23.000;0.000;1.000;16.000
  16/12/2006;17:26:00;5.374;0.498;233.290;23.000;0.000;2.000;17.000
  </code></pre>
  
  <p>Please help me to filter data corresponding to two dates say 1/2/2007 and 2/2/2007</p>