When using x m}"1 y to amend columns of y. Why can m only be a single-item list (rank 1) and why does x need to be rank 2?
e.g. ]tst=:(5 3$2) 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 (1 4 6 3 2) (1)}"1 tst |rank error | (1 4 6 3 2) (1)}"1 tst (1 4 6 3 2) (,1)}"1 tst |length error | (1 4 6 3 2) (,1)}"1 tst (,.1 4 6 3 2) (,1)}"1 tst 2 1 2 2 4 2 2 6 2 2 3 2 2 2 2 (,.1 4 6 3 2) (0 2)}"1 tst |length error | (,.1 4 6 3 2) (0 2)}"1 tst Yet the following are fine? |: (1 4 6 3 2) (1)} |: tst 2 1 2 2 4 2 2 6 2 2 3 2 2 2 2 |: (1 4 6 3 2) (0 2)} |: tst 1 2 1 4 2 4 6 2 6 3 2 3 2 2 2 I suspect this has to do with making sure the prefixes of the left & frames right frames match. Am I on the right track? Is working with the transpose the best way to accomplish something like this? ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
