> 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 <[email protected]> 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
