> Although, '' + 2 is not an error or 2, but it reads "empty + 2", > which I though would be 2. Hmm.
A different explanation is involved with this one. Basically, for a dyadic function (such as +) with ranks 0 0, if one argument is an atom, then the result has shape (and rank) of the other argument. A detailed explanation starts from + having ranks 0 0 and then follows from the general mechanism of function application. ----- Original Message ----- From: Matthew Brand <[email protected]> Date: Thursday, April 2, 2009 9:49 Subject: Re: [Jprogramming] trivial reshaping question To: Programming forum <[email protected]> > Thanks, that works. > > I had not come across ''$d. When I look at '' I think of > an empty > literal but it must count as empty "anything". I guess that fits > because if I want a loop that appends numerical results to a > list, I > initialize it with ''. > > e.g. > > r =. '' > for_i. i. 10 do. > r =. r , *: i > end. > > ''$ at first glance feels like it should not work since '' is not > really a number. But then again ''$y reads as "make y into shape x > where x is empty, i.e. make it into an empty shape" and, $ ''$y is > indeed ''. > > I guess I should have said to myself that I want to make y have empty > shape, and then ''$ would have followed naturally! > > Although, '' + 2 is not an error or 2, but it reads "empty > + 2", > which I though would be 2. Hmm. > > > On Thu, Apr 2, 2009 at 5:22 PM, Roger Hui <[email protected]> wrote: > > Use 0{d or ''$d > > > > > > > > ----- Original Message ----- > > From: Matthew Brand <[email protected]> > > Date: Thursday, April 2, 2009 9:19 > > Subject: [Jprogramming] trivial reshaping question > > To: Programming forum <[email protected]> > > > >> Something simple ... and a bit trivial I am stuck on ... > >> > >> d =. 1$1 > >> d 0} 1 2 3 > >> |rank error > >> > >> What can I do to d to make its shape fit into 0} 1 2 3? > >> > >> e.g. > >> (,d) 0} 1 2 3 > >> |rank error > >> | (,d) 0}1 2 3 > >> > >> Does not work. Could somebody suggest what to use instead of , > >> to make > >> this work? > >> -------------------------------------------------------------- > --- > >> ----- > >> For information about J forums see > http://www.jsoftware.com/forums.htm>> > > --------------------------------------------------------------- > ------- > > For information about J forums see > http://www.jsoftware.com/forums.htm> > > > > -- > http://www.ixquick.com/ > > Ixquick Protects Your Privacy! > The only search engine that does not record your IP address. > > http://www.vivapalestina.org/ > ----------------------------------------------------------------- > ----- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
