Hi all,
I have a sample of data  set with variables day, ID,var and month:
day ID var  Month
  1 11  x March
  1 11  x March
  1 11  x April
  1 11  y March
  1 11  x March
  1 11  y March
  2 11  x March
  2 11  y March
  3 11  x March
  3 11  y March
  4 11  y March

In the above data set there are four unique days within ID. For example
ID "11" has four records  on day 1 and if this ID has "y" in "March" then I
want keep "y"  and discard "xs". Is it possible to keep them in two data
sets ( wanted and unwanted)
The output for wanted data set will be:

1 11 y March
1 11 x April
1 11 y March
2 11 y March
3 11 y March
4 11 y March
thanks in advance

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