Hi All:
I was recently working with a dataset on arsenic poisoning. Among the variables in the dataset, I used the following three variables to produce crosstabulations (variable names: FOLSTAT, GENDER, ASBIN; all three were categorical variables, FOLSTAT denoted follow up status for the subjects and had seven levels, GENDER denoted sex (two levels: male,female), and ASBIN denoted binarized arsenic concentrations (two levels: "<0.05", ">0.05" denoting less than 0.05 mg/L and more than 0.05 mg/L respectively).
To illustrate, I used the following code for crosstabulation:
x <- table(FOLSTAT,GENDER,ASBIN)
# from the results, I then wanted to subset a table for the ASBIN
value ">0.05"
I used the following code to subset the table:
y <- x[,,ASBIN=">0.05"]
Two errors.
1) Your logical index won't work. For the second level of ASBIN, use x[,,2]. Since the third dimension of the table x has only 2 elements (one for each level of ASBIN), sending it a logical vector that is as long as your number of subjects (N) is only going to confuse it. It's going to run out of levels of table. And it did - "subscript out of ..."
1) Is this a cut-and-paste error?
> y <- x[,,ASBIN=">0.05"]
It won't work anyway, but for future reference, logical "equals" is ==, not =. In other words, "==" is a question, "=" is an assignment.
Cheers
Jason -- Indigo Industrial Controls Ltd. 64-21-343-545 [EMAIL PROTECTED]
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