R help - May 2014 - Combine factorial column intp a new column

Dear R-users,

I'd be very greatful if you could help me with the following as after a 
few tests I haven't still been able to get the right outcome.

I've got this data:
dd_1 <- data.frame(ID = c("1","2", "3",
"4", "5"),
                  Class_a = c("a",NA, "a", NA, NA),
                  Class_b = c(NA, "b", "b", "b",
"b"))

And I'd like to produce a new column 'CLASS':
dd_2 <- data.frame(ID = c("1","2", "3",
"4", "5"),
                  Class_a = c("a",NA, "a", NA, NA),
                  Class_b = c(NA, "b", "b", "b",
"b"),
                  CLASS = c("a", "b", "a-b",
"b", "b"))

Thanks a lot!

Hi,
May be this helps:
?ddNew <-? transform(dd_1, CLASS=
gsub("NA-|-NA","",paste(Class_a, Class_b,
sep="-")))
?identical(ddNew, dd_2)
#[1] TRUE
A.K.


On Thursday, May 22, 2014 4:07 AM, Beatriz R. Gonzalez Dominguez
<aguitatierra at hotmail.com> wrote:
Dear R-users,

I'd be very greatful if you could help me with the following as after a 
few tests I haven't still been able to get the right outcome.

I've got this data:
dd_1 <- data.frame(ID = c("1","2", "3",
"4", "5"),
? ? ? ? ? ? ? ? ? Class_a = c("a",NA, "a", NA, NA),
? ? ? ? ? ? ? ? ? Class_b = c(NA, "b", "b", "b",
"b"))

And I'd like to produce a new column 'CLASS':
dd_2 <- data.frame(ID = c("1","2", "3",
"4", "5"),
? ? ? ? ? ? ? ? ? Class_a = c("a",NA, "a", NA, NA),
? ? ? ? ? ? ? ? ? Class_b = c(NA, "b", "b", "b",
"b"),
? ? ? ? ? ? ? ? ? CLASS = c("a", "b", "a-b",
"b", "b"))

Thanks a lot!

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