Erling, Jx is NOT J!
Please do not report 'strange results' from Jx to the J programming forum! This can cause all kinds of unnecessary confusion. You can report strange Jx results to the chat forum. On Sat, Dec 16, 2017 at 7:15 AM, Erling Hellenäs <[email protected]> wrote: > Hi ! > > I get > > 0x1 > 0 > eu=:2.71828 > 0*eu^0 > 0 > > This is J8.06 with Jx patches. > > Cheers, > Erling Hellenäs > > > On 2017-12-16 12:19, [email protected] wrote: > >> Hi. >> >> Could someone please shed some light on the following behavior: >> >> 1p1 >> 3.14159 >> 0p1 >> 0 >> 0p0 >> 0 >> 1x1 >> 2.71828 >> 0x1 >> 2.71828 >> 0x0 >> 0 >> >> I don't understand why 0x1 isn't the same as 0 * ^1 even though >> other constants seem to obey this form. I haven't found any >> explanation in >> http://www.jsoftware.com/docs/help806/dictionary/dcons.htm . >> >> <information irrelevant to the question> >> >> I am new to J and am yet to write a useful script in it, but >> I've already been greatly impressed by how consistent the >> language felt in most cases. For example, just the other day >> I wrote a monadic verb which took $n$ as an argument and >> returned $\sum_k {n \choose 3k}$. The verb was the following: >> >> a =: [:+/(3*i.)!] >> >> But if you try to pass it not a single $n$ but a list, the >> verb doesn't work. Which is a shame because the intended use >> was to examine the series. And so I started searching for >> something akin to Haskell's `map`. After half an hour of >> sifting through J tutorials that expressed delight in the >> fact that J lifts operations to arrays of arbitrary ranks >> by default and therefore doesn't need `map`, I've finally >> found what I was looking for, namely `a "0 i.50`, the rank >> operator, and it turned out that `map` isn't magic after >> all and is just a single case of a more general operation. >> I hadn't seen the rank operator in any language before and >> was thrilled to feel the potential that this operator holds. >> >> So the language is great, and it seems that common use cases >> are handled by elegant general solutions, that is, the >> language is designed to be mostly free from corner cases. >> >> That's why the unintuitive handling of 0x1 seems to me >> especially weird. I could ignore it if Python did it, if >> C++ did it, but J simply doesn't look like a language that >> intoduces inconsistencies for no reason. So it is highly >> probable that it's me who doesn't understand higher purpose >> of the construct. And so I came here hoping that someone >> explains it to me. The J community has a reputation of >> being tolerant to uninsightful questions of beginners. >> >> </information irrelevant to the question> >> >> Sorry if my English has some mistakes or is in the wrong >> tone. The reason isn't negligence, it's just that English >> isn't my native language. >> >> Regards, >> Dmitry Khalansky. >> ---------------------------------------------------------------------- >> 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
