Module 11. Debugging and Defensive Programming in R

 


Error message reads: Error in outliers[, j] && tukey.outlier(x[, j]) : 'length = 10' in coercion to 'logical(1)'

Diagnosis of the bug: The problem happens because both outliers[, j] and tukey.outlier(x[, j]) are vectors with several values (for example, 10 each). In R, the && operator only checks the first value from each vector and gives back one TRUE or FALSE. That means it’s not looking at all the elements, just the first ones. So when the code tries to use && on two full vectors, it basically tries to squeeze all those values into one single logical result, which causes the error about “length > 1.” To fix this, we should use & instead, because that operator works element by element across the whole vector.

Results after debugging:


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