To my knowledge, J602 is still the best place for labs. To fix that, I imagine we need some people (who have experience writing labs) to tackle porting the lab mechanisms to newer versions of J. It's not going to be perfect, though, especially in the initial attempts.
Mostly, I think it's a matter of someone having the interest and drive to do it. We have more than enough talent here to offer advice when problems arise. (And sometimes that advice might even be correct.) Thanks, -- Raul On Wed, Apr 23, 2014 at 3:10 PM, robert therriault <bobtherria...@mac.com>wrote: > Hey Raul, > > The subject of my conference talk was going to be jsoftware.com as a > learning ecology and labs are a big part of that (and could become bigger). > I have not seen a specific lab author since J602. Do you know of one or are > we following the "use any text editor" advice? > > http://www.jsoftware.com/jwiki/Labs > > Cheers, bob > > On Apr 23, 2014, at 11:23 AM, Raul Miller <rauldmil...@gmail.com> wrote: > > > If you are interested, you might consider putting together a J lab on the > > subject. > > > > This would: > > > > (a) Help you retain the concepts for yourself, and expand your > > understanding of them, and > > (b) Help convey them to other people, also. > > > > If this interests you, we can help point you at lab authoring > > documentation. We need some people interested in writing some labs > because > > the new platforms (especially phones) have UI adaptations which need some > > fixing, for labs. > > > > Meanwhile, one of the more important issues for an author is finding a > good > > reviewing audience to work with. (Even more important, of course, is > > writing stuff.) > > > > Thanks, > > > > -- > > Raul > > > > > > On Wed, Apr 23, 2014 at 1:52 PM, alexgian <alexg...@blueyonder.co.uk> > wrote: > > > >>> The information and more are in the vocabulary page for %. > >> > >> Well, yes, but so tersely and compactly expressed that you have to know > the > >> long answer before you understand it! I did look at the Vocab page, but > >> didn't "get it", that's why I posted. > >> > >> It needed Roger's somewhat more expanded explanation for those of us > that > >> are somewhat slower on the uptake. That's why I said the Vocab could > use a > >> touch up. It is NOT user friendly, more of an ultra-coded reference. > Of > >> course, you might not see it this way, but I'd bet most newcomers would. > >> > >> And it's not as if there is a longer explanation somewhere else, is > there? > >> Well, other than this thread, I mean... :) > >> > >> > >> > >> On 23 April 2014 18:17, Roger Hui <rogerhui.can...@gmail.com> wrote: > >> > >>> The information and more are in the vocabulary page for %. > >>> http://www.jsoftware.com/help/dictionary/d131.htm . > >>> > >>> > >>> On Wed, Apr 23, 2014 at 10:02 AM, alexgian <alexg...@blueyonder.co.uk > >>>> wrote: > >>> > >>>> Great info, thanks Roger. > >>>> If it was up to me, I'd DEFINITELY include that in the Vocabulary, is > >> it > >>>> even documented anywhere else? > >>>> > >>>> > >>>> On 23 April 2014 17:33, Roger Hui <rogerhui.can...@gmail.com> wrote: > >>>> > >>>>> %. x for a vector x is the same as ($x)$%.,.x, and the key expression > >>> is > >>>>> %.,.x, the "matrix inverse" of a 1-column matrix. b=.y%.x on a tall > >>>> matrix > >>>>> x is solving a least-squares problem, the coefficients b that > >> minimizes > >>>> the > >>>>> sum of squares of y - x +/ .* b . > >>>>> > >>>>> In addition, for a non-zero vector x, (%.x) +/ .* x is 1, a special > >>> case > >>>> of > >>>>> that (%.x)+/ .* x is an identity matrix, whence one can deduce that > >> for > >>>>> vector x, %.x is x%+/x^2. > >>>>> > >>>>> ] x=: 7 ?.@$ 100 > >>>>> 94 56 8 6 85 48 66 > >>>>> %. x > >>>>> 0.00362137 0.00215741 0.000308202 0.000231152 0.00327465 0.00184921 > >>>>> 0.00254267 > >>>>> (%.x) +/ .* x > >>>>> 1 > >>>>> x % +/x^2 > >>>>> 0.00362137 0.00215741 0.000308202 0.000231152 0.00327465 0.00184921 > >>>>> 0.00254267 > >>>>> > >>>>> M=: 7 3 ?.@$ 100 > >>>>> (%.M) +/ .* M > >>>>> 1 5.55112e_17 _2.77556e_17 > >>>>> _1.21431e_16 1 1.11022e_16 > >>>>> _4.85723e_17 1.94289e_16 1 > >>>>> > >>>>> > >>>>> > >>>>> On Wed, Apr 23, 2014 at 9:13 AM, alexgian <alexg...@blueyonder.co.uk > >>> > >>>>> wrote: > >>>>> > >>>>>> Just wondering: > >>>>>> %. 2 3 4 > >>>>>> 0.0689655 0.103448 0.137931 > >>>>>> > >>>>>> Which is fair enough enough at one level, I suppose, since the dot > >>>>> product > >>>>>> of the two arrays IS 1, but what system/equation is being solved > >>> here? > >>>>>> Obviously, there are infinite solutions. Why that one? > >>>>>> IOW, which "matrix" is being inverted here? > >>>>>> > >>>>>> Thanks > >>>>>> > >>> ---------------------------------------------------------------------- > >>>>>> 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 > >>>> > >>> ---------------------------------------------------------------------- > >>> 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 > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
