Dan - I see your message in my G-mail thread about using indexing (via double grade) to achieve insertion. It's not one that would have occurred to me.
Where were you looking to see your message appear? (Oddly, when I first glanced at your message yesterday, I thought it was from Dan Bron.) Regards, Devon On Sat, Jan 10, 2009 at 11:44 AM, Dan Baronet <[email protected]> wrote: > I sent a msg yesterday and I don't see it in the forum nor has it come back > to me. Anybody seen it (for this topic)? > /Dan > > --- On Fri, 1/9/09, Devon McCormick <[email protected]> wrote: > > > From: Devon McCormick <[email protected]> > > Subject: Re: [Jprogramming] Matrix spread > > To: "Programming forum" <[email protected]> > > Date: Friday, January 9, 2009, 5:36 PM > > This is not as direct as the solutions using expansion with > > a complex > > expander but it's one of those things I thought of and > > it worked the first > > time just as I'd conceived it: concatenation under > > rotation: > > > > 0,&.(4&|."1)0,&.(4&|.)>:i.5 5 > > 1 2 3 4 0 5 > > 6 7 8 9 0 10 > > 11 12 13 14 0 15 > > 16 17 18 19 0 20 > > 0 0 0 0 0 0 > > 21 22 23 24 0 25 > > > > The only advantage it might have would be for inserting > > non-zero rows or > > columns. > > > > The symmetry of inserting both the same row and column > > makes me wonder if > > there's a more general, adverbial method to do both at > > once. > > Experimentation showed me this: > > > > (0&,&.(4&|.)) (1 : 'u u"1 > > y')mat > > 1 2 3 4 0 5 > > 6 7 8 9 0 10 > > 11 12 13 14 0 15 > > 16 17 18 19 0 20 > > 0 0 0 0 0 0 > > 21 22 23 24 0 25 > > > > Which extends interestingly (though maybe not usefully): > > > > (0 99&,&.(4&|.)) (1 : 'u u"1 > > y')mat > > 1 2 3 4 0 99 5 > > 6 7 8 9 0 99 10 > > 11 12 13 14 0 99 15 > > 16 17 18 19 0 99 20 > > 0 99 0 0 0 0 0 > > 21 22 23 24 0 99 25 > > > > On Fri, Jan 9, 2009 at 4:47 PM, Raul Miller > > <[email protected]> wrote: > > > > > On Fri, Jan 9, 2009 at 4:40 PM, Brian Schott > > <[email protected]> > > > wrote: > > > > I think this is more complete. > > > > > > > > 1 1 1 1j1 1 #"1]1 1 1 1j1 1 #>:i. 5 5 > > > > 1 2 3 4 0 5 > > > > 6 7 8 9 0 10 > > > > 11 12 13 14 0 15 > > > > 16 17 18 19 0 20 > > > > 0 0 0 0 0 0 > > > > 21 22 23 24 0 25 > > > > > > Yes, thank you, I did not read carefully enough. > > > > > > Or: > > > m=:1+i.5 5 > > > b=:1 1 1 1 0 1 > > > b #inv b#inv"1 m > > > 1 2 3 4 0 5 > > > 6 7 8 9 0 10 > > > 11 12 13 14 0 15 > > > 16 17 18 19 0 20 > > > 0 0 0 0 0 0 > > > 21 22 23 24 0 25 > > > > > > -- > > > Raul > > > > > ---------------------------------------------------------------------- > > > For information about J forums see > > http://www.jsoftware.com/forums.htm > > > > > > > > > > > -- > > Devon McCormick, CFA > > ^me^ at acm. > > org is my > > preferred e-mail > > ---------------------------------------------------------------------- > > For information about J forums see > > http://www.jsoftware.com/forums.htm > > > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > -- Devon McCormick, CFA ^me^ at acm. org is my preferred e-mail ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
