< quote href = http://www.jsoftware.com/help/jforc/declarations.htm > The result of dyad $ has the frame x relative to the rank of the items of y, and is made up of the items of y, repeated cyclically as needed. It follows that the shape of this result is x concatenated with the shape of an item of y . < / quote >
1 - I dont understand "relative to the rank of the items of y" How is frame (shape) relative to the rank of an array? 2 - x concatenated with the shape of an item of y cannot work when x is an empty list. The author gives this example: <example> (0 $ 2) $ 2 2 Here (0 $ 2) produces an empty list, as we saw above, and that is the x to the second $ . The items of y are still scalars, so the result has shape empty (an empty list concatenated with an empty list), i. e. it is a scalar. </example> but (0 $ 2) produces an empty list. So using our understanding of what x $ y does (the shape of this result is x concatenated with the shape of an item of y .) , we can see that we cannot concatenate x in this case because it is not a shape but an empty list. ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
