Dear R users,I come to you with a quite silly question I think, but I hope you can answer me... That is, I've got some problems in using the if and while conditions in a loop. Substantially, I want to select rows in a dataset depending on an index variable (suppose it ranges from 1 to 5), so to make a specific analysis (homemade of course) on thie new dataset. Mi first tought has been to do a double loop like this:
for i in 1:5{ for j in (i+1):5{ data = dataset[(variable==i) | (variable==j),] ##analysis ##analysis } } This way I should select all the couples only once (gaining in efficiency I hope). The fact is that this arrangement has a problem: that j ends up with ranging from 2 to 6, not from to 2 to 5. So when I do a subsetting on the dataset to obtain only the rows corresponding to the values of i and j I want, when the loop comes to j = 6 I have an error, of course. What I want to know is: how can I use the if or while condition in such a loop to avoid the routine doing the computations for this case? I.e., can I tell somehow R "Hey, if j=6, let it go and move on with the other computations"? Or maybe you can see a faster and better way of using the for conditions?? I hope I made myself clear, if not I'll carify myself!! Thanks in advance Niccolò [[alternative HTML version deleted]]
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