Extracts incomplete cases from a data set in r : <p>from this example:   </p>

<pre><code>    ## x
   ##  v1 v2 v3
   ##1 90 55 NA
   ##2 NA 45  8
   ##3 85 NA  5
   ##4 NA 33  7
   ##5 55 30  4
   ##6 60 20  3
   ##7 75 15  2
   ##8 80 23  6
     # ici is where Incomplete case indicator 

     ici=(function (x) 
     return(is.na(x)))

    ici(x)
            v1    v2    v3
  ##  [1,] FALSE FALSE  TRUE
  ##  [2,]  TRUE FALSE FALSE
  ##  [3,] FALSE  TRUE FALSE
  ##  [4,]  TRUE FALSE FALSE
  ##  [5,] FALSE FALSE FALSE
  ##  [6,] FALSE FALSE FALSE
  ##  [7,] FALSE FALSE FALSE
  ##  [8,] FALSE FALSE FALSE

     # Extracts incomplete cases from a data set

     ic=(function (x, drop) 
     return(x[ici(x)]))(x, drop)

     ic(x)
   ## Error: could not find function "ic"
</code></pre>

<p>from the last run ( Error: could not find function "ic") why it give me this and how I solve this broblem with function ic</p>
