Creating Dummy Variables with if else phrase

Dear All,

I want to do 52 state dummy variables. In order to make it easier
for me, I thought of using the below commands. (x is the vector with
state variables, matrix will correspond to the dummy variables)

x <- c(1,2,NA,4)
matrix <- matrix(0,nrow=4,ncol=4)

for (i in 1:4) {
if (is.real(x[i])) {
matrix[i,x[i]] <- 1 } else {
matrix[i,] <- rep(NA,4)
}
}

This gives me the following matrix:

1  0  0  0
0  1  0  0
0  0  0  0
0  0  0  1

But I want it to look as follows:

1   0  0  0
0   1  0  0
NA NA NA NA
0   0  0  1

I don't really understand why you want to create a matrix that way, 
but if you want to do it the way described above
  is.real(x[i])
seems to be the wrong function (because x is a real vector in the 
example above). If you want to test for NA you should use
  !is.na(x[i])
instead.
Z
I want the forth row to be NA, but it is unchanged, i.e., 0. The
second "else" phrase does not seem to work, and I cannot see what is
wrong.

I would be very grateful for your help.

Regards, Sophie

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Creating Dummy Variables with if else phrase

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