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I have a contingency table computed from the out of sample observations. In some cases not all classes are represented in the out of sample and hence do not appear. I want to coerce the contingency table to report zeros for classes not in the out of sample. How can I do it efficiently. For example my contingency table is

  x z
x 1 2
y 1 3
z 2 2

but i want it to look like

  x y z
x 1 0 2
y 1 0 3
z 2 0 2
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closed as off-topic by gung, Andy, Scortchi, ttnphns, Nick Stauner May 17 at 20:20

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This question appears to be off-topic because it is about how to use R's table function. –  gung May 17 at 13:56
    
sorry I did not realize I posted on CV while I meant to post to SO. admins please move it to SO. Thank you. –  earthlink May 17 at 20:31
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1 Answer 1

up vote 3 down vote accepted

Read the manual. This is explained in the documentation for table(). You simply set useNA="ifany".

Your edit does not constitute a reproducible example. If setting the useNA argument does not resolve your problem, it may be that R doesn't recognize that that level of your factor exists. Assuming your column factor is f.c, try f.c <- factor(f.c, levels=c("x","y","z")) prior to calling table(). If that isn't the solution, you will need to add a truly reproducible example.

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I had tried it but this does not solve my problem. I added some examples to show my problem. –  earthlink May 17 at 20:32
    
Thank you, that solved my problem. –  earthlink May 21 at 0:07
    
You're welcome. –  gung May 21 at 0:50
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