It just takes a long time. Do you really mean to compute the determinant of a non-square matrix? For a square matrix, the interpreter uses fast (n^3) special code; for a non-square matrix, it uses the general !n code. e.g.
6!:2 '-/ .* m' [ m=: 8 8 ?...@$ 10 9.24699e_5 6!:2 '-/ .* m' [ m=: 8 7 ?...@$ 10 0.0602373 6!:2 '-/ .* m' [ m=: 9 9 ?...@$ 10 5.81079e_5 6!:2 '-/ .* m' [ m=: 9 8 ?...@$ 10 0.602606 6!:2 '-/ .* m' [ m=: 10 10 ?...@$ 10 0.000100013 6!:2 '-/ .* m' [ m=: 10 9 ?...@$ 10 5.56612 6!:2 '-/ .* m' [ m=: 11 11 ?...@$ 10 6.70476e_5 6!:2 '-/ .* m' [ m=: 11 10 ?...@$ 10 61.0679 ----- Original Message ----- From: John Wilson <[email protected]> Date: Monday, May 25, 2009 10:33 Subject: [Jprogramming] determinant of 16x15 matrix seems to hang J To: Programming forum <[email protected]> > This appears to hang J. > > M =: ? 16 15$10 > det =: -/ . * > N =: det M ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
