title: How to use setorder function in R
body: <p>I have a mock up data set:</p>
  
  <pre><code>d1 = structure(
    list(
      chan1 = c(1.49955768204777, 1.57924608282282, 
                1.62079872172079, 1.49955768204777,
                1.50897108417039, 1.47897959168283),
      chan2 = c(3.71459266186863, 3.71459266186863,
                3.66763591782946, 3.67359273988532,
                3.66408366995924, 3.68083665073346),
      chan3 = c(8.32529316285155, 6.30229174858652,
                6.97551768293611, 6.52653674461786,
                6.52653674461786, 6.07823977152575),
      chan4 = c(11.023719681933, 11.023719681933, 
                11.023719681933, 11.4613297390623,
                11.4613297390623, 11.5813471428122),
      chan5 = c(7.32862391337389, 7.38103675023449,
                7.81796038841145, 7.4216715642288,
                7.51924428352424, 7.35498863975821),
      rowname = c(2042051, 1454646, 289170,
                  3307469, 3890829, 1741489),
      total_conv = c(359.161333500186, 359.161312264452,
                     359.16130836516, 359.161294408793,
                     359.161289598969, 359.161209958641),
      sum = c(31.8917871020749, 30.0008869254455, 
              31.1056323928309, 30.5826884698421,
              30.6801655213341, 30.1743917965125)
    ),
    .Names = c("chan1", "chan2", "chan3", "chan4", "chan5",
               "rowname", "total_conv", "sum"),
    class = "data.frame",
    row.names = c(NA, -6L)
  )
  </code></pre>
  
  <p>Now I need to sort this data set by <strong>total_conv</strong> and <strong>sum</strong> variables.
  Here total_conv should be sort in descending order and sum in ascending order.</p>
  
  <p>When I use the following function, I unable to sort my data set in required format.</p>
  
  <pre><code>d1&lt;-setorder(as.data.table(d1),-total_conv,sum)
  </code></pre>
  
  <p>How can I overcome this issue?</p>