Assume I have a dataset of shape 4 4 data=: 4 4 $ i. 16 and some other data of shape 2 4 (i.e. same number of columns, different number of rows)
other=: 2 4 $ 100 200 130 250 2 4 6 8 I want to subtract each row of other from data, so that the result has shape 2 4 4. i.e. I know the result of each row of other subtracted from the whole of data. The way I do this is: data -"1 1"_ 1 other For me, at least, chaining " is a new concept. I didn't know it was possible until relatively recently. I find it slightly ugly because, for me, it is very difficult to figure out how the ranks of the verb and the nouns all interact. But is this a J-esque way to solve the above problem? Are there other ways to solve it? Extra: Because the above example is slightly contrived, I will just give a more concrete example. Suppose I have a dataset X, of shape A B, and I have a collection, Y, of "average values" of other datasets, where the collection has shape C B, each row of Y being an average of some dataset. I want to know the values of the first dataset minus each average. So X -"1 1"_ 1 Y gives this result, and it has shape C A B. Thanks, Jon ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
