title: R - How to delete rows with certain dates
body: <p>I have a dataframe like this:</p>
  
  <pre><code>x1= c("Station 1", "Station 1", "Station 2", "Station 3", "Station 3", "Station 3")
  x2= c("1993-06-08", "1994-06-09", "1982-06-10", "1993-06-11", "1992-06-12", "1997-06-13")
  x3= seq(5, 30, length=6)
  x4= seq(4, 16, length=6)
  x5= seq(10, 60, length=6) 
  
  testframe = data.frame(Station=x1, Date=x2, Morning=x3, Noon=x4, Evening=x5) 
  
  testframe[,2] = as.Date(testframe[,2], format="%Y-%m-%d")
  class(testframe$Date) 
  </code></pre>
  
  <p>Now I want to remove all rows that are recorded before 1993-01-01.</p>
  
  <p>I did this:</p>
  
  <pre><code>index = testframe[,2] &gt;= "1993-01-01" 
  </code></pre>
  
  <p>And it gives back the right list of True and False, but I dont know how to go on.</p>
  
  <p>I tried this, but without success:</p>
  
  <pre><code>new = testframe[index]
  new = [-c(testframe[index]),]
  </code></pre>
  
  <p>Can somebody help? I know it should be really easy, but I dont get it.</p>