Experimenting with Euler Problem 731, I should get: %3(] * <.@^)2<.@^>: i.3. NB. 1/(b^(c^k).c^k) in maths notation 0.0555556 0.00308642 1.9052e_5 %3x(] * <.@^)2x<.@^>: i.3. NB. Try extended nos 1r18 1r324 1r52488
+/\%3x(] * <.@^)2x<.@^>: i.3. NB. Cum sum 1r18 19r324 3079r52488 23j20":,.+/\%3x(] * <.@^)2x<.@^>: i.3. Looking for repeated pattern .... 0.05555555555555555556 0.05864197530864197531 0.05866102728242645938 Only using k=1,3 here for concise display. This is the sort of thing I see here on the iPad, and also in J901 However, in J902 beta i, I get (can’t email from Windows just now, so faking it!): +/\%3x(] * <.@^)2x<.@^>: i.3. 0 0 0 My mistake!? Thanks, Mike Sent from my iPad > On 25 Oct 2020, at 16:42, Henry Rich <[email protected]> wrote: > > Modern J uses a virtual block for the result of (, y), so now (+/@, y) and > (+/ , y) run at the same speed. A different example is needed. > > Henry Rich > >> On 10/25/2020 12:01 PM, Brian Schott wrote: >> Jan-Pieter, >> >> First, thanks for pointing out the link. >> But I am having some problems. >> >> [*******my comment 0) here is likely inappropriate in light of Henry's >> reply in this thread >> 0) Are you suggesting that some wording be added to that link? It looks to >> me as if you are but where? >> I say where because there are at least 3 different concepts treated on that >> page: SC, EIP, and AIP. >> ] >> >> >> 1) I am finding problems on that page that I cannot explain. For example, >> a) on one line discussing EIP the following is stated twice, when it is >> clear that the two should be different `(V0@[ V1 V2)` . >> b) [this comment may also be explained by Henry's reply but I don't see how] >> I cannot confirm the improvements suggested by the example there. >> Perhaps using j807 is the problem. See my session below. >> 9!:52'' >> 1 >> a =: 1000 1000 ?@$ 0 NB. it is unfortunate that the +/ result >> suggests that a contains integers, not reals >> +/ , a NB. perhaps 1000 1000 >> could be reduced to 25 25? >> 499960 >> +/@, a >> 499960 >> ts =: 6!:2 , 7!:2@] >> ts '+/ , a' NB. notice the small space usage here >> 0.001987 1408 >> ts '+/@, a' NB. the time reduction is so small as to be >> "within statistical error" >> 0.001965 1536 >> JVERSION >> Engine: j807/j64/darwin >> Release-c: commercial/2019-02-24T10:50:40 >> Library: 8.07.26 >> Platform: Darwin 64 >> Installer: J807 install >> InstallPath: /users/brian/j64-807 >> Contact: www.jsoftware.com >> >> On Sun, Oct 25, 2020 at 8:42 AM Jan-Pieter Jacobs < >> [email protected]> wrote: >> >>> I guess this is worth mentioning here: >>> >>> https://code.jsoftware.com/wiki/Vocabulary/SpecialCombinations#Assignments_In_Place_.28AIP.29 >>> >>> Assignments are done in place if you use a specific form recognised by the >>> interpreter. >>> >>> If you do not assign the result, or use it in a longer sentence, it will >>> not be recognised, copying over the entire array, rather than updating a >>> single element. >>> >>> Best regards, >>> >>> Jan-Pieter >>> >>> >>> -- >> (B=) >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm > > > -- > This email has been checked for viruses by AVG. > https://www.avg.com > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
