Re: [R] Count missing variables in dataset

From: Achim Zeileis <>
Date: Mon 21 Mar 2005 - 22:37:18 EST

On Mon, 21 Mar 2005 12:07:16 +0100 Jan Sabee wrote:

> I have a problem about how to count missing variables in dataset.
> I have a question for my customer. They are must choice one of answer
> for example: A, B, C, D and E.
> Now, I have dataset which is the result from my question, for
> instance:
> x1 x2 x3 x4 x5
> A A A B A
> C A A A A
> B B A B A
> B B B C A
> A B B B B
> C B B B A
> I know that my customer only choice A, B and C.
> Are there any way to count variables that are not include in dataset.
> I mean D and E is missing in dataset.

You just need to set up the variables properly. If you just say:

R> x <- factor(sample(LETTERS[1:3], 5, replace = TRUE)) R> summary(x)
1 2 2

R will assume that the only levels available are A-C. But if you tell R

R> x <- factor(x, levels = LETTERS[1:5]) R> summary(x)
1 2 2 0 0

it will do what you want. Just provide the full choice set as levels to the corresponding variables.

> Thanks for your help.
> Jan Sabee
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> mailing list PLEASE do read the posting guide! Received on Mon Mar 21 22:50:50 2005

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