Not a bad idea Raul, I still haven't installed it on any of my Android devices (phone or tablet) but am looking to do so. If that works I'd be more than happy to contribute whatever is within my abilities.
On 23 April 2014 19:41, alexgian <alexg...@blueyonder.co.uk> wrote: > Thanks Bob > > Nice call. I might start using that, even if only for comparison. > I'll be the first to admit that I haven't been on the friendliest of terms > with the std Vocabulary. Well, alright... but only sometimes. > > > > On 23 April 2014 18:58, robert therriault <bobtherria...@mac.com> wrote: > >> Hey Alex, >> >> You may want to take a look at NuVoc, the jwiki section that I think that >> Ian Clark organized just for the reason that you are describing. :) >> >> http://www.jsoftware.com/jwiki/NuVoc >> >> Cheers, bob >> >> >> On Apr 23, 2014, at 10:52 AM, 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
