search for: diagnosis3

...or how to join two (or more) frequency tables. Why would I want to do that and what do I mean by "joining" ? Let me try to explain: I have a diagnosis form that allows registration of up to three diagnosis codes on animals with birth defects, like this: father.id diagnosis diagnosis2 diagnosis3 a 100 200 300 b 200 100 340 .... and so on. As you can see the same diagnosis can show up in either field (1, 2 or 3). I am interested in how many times each diagnosis shows up for offspring from the same father (looking at inherita...

...tent of the matrix. However, as can been seen in the dataframe, some observations are missing and should result in <NAs> in the resulting matrix, giving a result like this: marker 1 2 3 diagnosis1 value value value diagnosis2 value value value diagnosis3 value NA value Can anyone help out with some code for this? I have tried to look this up in the mailing list as it has probably been answered before but only found aspects of the problem which I was just not able to plumb together. Many thanks in advance, I hope this is not to much...