Here is the Pesch [1986] paper. http://www.jsoftware.com/papers/EmptyFrames.htm /Erling
On Wed, 20 Dec 2017 21:17:58 +0100, Erling Hellenäs wrote: > Moved the thread to chat. /Erling > > On 2017-12-20 19:32, Erling Hellenäs wrote: > > Hi all! > > > > Thanks, I will look into the details tomorrow, but yes , and I see a > > number of problems with this as mentioned in this post: > > http://www.jsoftware.com/pipermail/programming/2017-December/050179.html > > In this thread I am trying to discuss strategies to solve these problems. > > Pesch[1986] might give us relevant information about this. Thanks! > > > > Cheers, > > Erling Hellenäs > > > > > > On 2017-12-20 17:21, Jose Mario Quintana wrote: > >>> For this to happen J functions have to be defined for handling > >>> arrays of > >> nothing? > >> > >> I have not followed this thread, or any other recent thread, closely but > >> this might shed some light: > >> > >> " > >> Zero Frame. If the frame contains 0 (as in 3 *"1 i. 0 4), there are no > >> argument cells to apply v to, and the shape of a result cell (the > >> value of > >> sir) is indeterminate. Pesch [1986] describes a variety of > >> strategies to > >> address this problem. In J, the shape is calculated if v is uniform (see > >> below); otherwise v is applied to a cell of fills. > >> " > >> > >> Rank and Uniformity Roger K.W. Hui > >> > >> http://www.jsoftware.com/papers/rank.htm > >> > >> I hope it helps > >> > >> > >> On Wed, Dec 20, 2017 at 4:03 AM, Erling Hellenäs > >> > >> wrote: > >> > >>> Hi all ! > >>> > >>> Could we avoid doing these peculiar things in the rank operator if we > >>> enabled the handling of arrays of nothing? > >>> > >>> The verb injected in Rank would then have to give a valid result for an > >>> array of nothing? > >>> > >>> For this to happen J functions have to be defined for handling > >>> arrays of > >>> nothing? > >>> > >>> Would it be possible to define an algebra for the handling of arrays of > >>> nothing? > >>> > >>> Could this be the same as enabling missing data? > >>> > >>> Cheers, > >>> > >>> Erling > >>> > >>> > >>> > >>> Den 2017-12-20 kl. 09:46, skrev Erling Hellenäs: > >>> > >>>> This is a mathematical concept: https://en.wikipedia.org/wiki/ > >>>> Empty_product /Erling > >>>> > >>>> > >>>> Den 2017-12-20 kl. 09:39, skrev Erling Hellenäs: > >>>> > >>>>> */i.0 > >>>>> > >>>>> 1 > >>>>> > >>>>> Here the interpreter automatically adds a 1 to get this peculiar > >>>>> result. > >>>>> > >>>>> /Erling > >>>>> > >>>>> Den 2017-12-19 kl. 20:01, skrev Raul Miller: > >>>>> > >>>>>> An empty tank zero array would be inconsistent. > >>>>>> > >>>>>> The number of elements in an array is the product of its > >>>>>> dimensions, and > >>>>>> the multiplicative identity is 1, not 0. > >>>>>> > >>>>>> 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
