Selecting Variables
Try this:
data.frame(ID = x$ID,
Max_Exposure = max(rowSums(x[,-1] == "y")),
Unique_Exposure = rowSums(x[,-1] == "y"))
On Tue, Aug 5, 2008 at 10:21 AM, Michael Pearmain <mpearmain at google.com> wrote:
Hi All,
i have a dataset that i want to dynamically inspect for the number of
variables that start with "Exposure_" and then for these count the entries
across each case i.e
ID Exposure_1 Exposure_2 Exposure_3
1 y y y
2 y y -
3 y - -
So the corresponding new variables that would be created are
ID Max_Exposure Unique_Exposure
1 3 3
2 3 2
3 3 1
I know this may seem fairly basic but it will give me the starting point to
develop more advanced things with loop and nat lang
Thanks in advance
Mike
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