THANKS, Henry! Bob
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Henry Rich Sent: July 26, 2008 12:07 PM To: 'Programming forum' Subject: RE: [Jprogramming] Amend question (100* 0{"2 mat) 0}"2 mat instead, try (100* 0{"2 mat) 0}"1 2 mat or (100* 0{"2 mat) 0}"_1 mat or (100* 0{"2 mat) (<a:;0)} mat Henry Rich > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Robert O'Boyle > Sent: Saturday, July 26, 2008 11:00 AM > To: [email protected] > Subject: [Jprogramming] Amend question > > Hi, all. This is a real newbie question involving amend }. I have an > arbitrary matrix MAT = 2 3 4 $ i.100. > > mat > > 0 1 2 3 > > 4 5 6 7 > > 8 9 10 11 > > > > 12 13 14 15 > > 16 17 18 19 > > 20 21 22 23 > > > > I want to substitute the first row of each plane with new > lists. I extract > the original lists and multiple them by 100 by 0{"2 mat > > > > 100* 0{"2 mat > > 0 100 200 300 > > 1200 1300 1400 1500 > > > > Now comes the surprise. I can't reverse the process of > amending the original > matrix with amend } > > > > (100* 0{"2 mat) 0}"2 mat > > |rank error > > | (100*0{"2 mat) 0}"2 mat > > > > I can do this with explicit indexing > > > > (100* 0{"2 mat) (<0 1; 0; 0 1 2 3) } mat > > 0 100 200 300 > > 4 5 6 7 > > 8 9 10 11 > > > > 1200 1300 1400 1500 > > 16 17 18 19 > > 20 21 22 23 > > > > But when I tried using a: to index all planes and columns, I > get a length > error > > > > (100* 0{"2 mat) (<a:; 0; a:) } mat > > |length error > > > > I tried parentheses and the like but still got the error. I > suspect this one > is simple syntax but the first one puzzles me. > > > > Any wisdom on this would be much appreciated. > > > > Bob > > > > > > > > ---------------------------------------------------------------------- > For information about J forums see > http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
