I can reproduce this problem. Defining DP=:40 and then defining ln, under j902 beta-h: 0j4":ln 2 0.6931 0j4":ln 3 1.0986 0j4":ln 2 3 0.6931 43.0000
Doing the same under j807: 0j4":ln 2 0.6931 0j4":ln 3 1.0986 0j4":ln 2 3 0.6931 1.0986 Thanks, -- Raul On Sat, Oct 10, 2020 at 4:39 PM Don Guinn <[email protected]> wrote: > > Playing with Roger's page for calculating extended precision > transcendental functions, "Essays/Extended_Precision_Functions", I found an > error in Beta J, not his definitions. There appears to be an error in the > handling of $: as to the rank of monadic "ln". Probably other functions in > the essay have the same problem. In trying to better isolate the problem I > had a J crash and a stack error. Hopefully the miscalculation and the stack > error are sufficient to isolate the error; however, I can send the J crash > if necessary. > > In J6 it treats the modac rank of ln as 0, but it is unclear what the > monadic rank of ln is. > > This is the original problem: > > ln=: DP&$: : (4 : 0) " 0 > assert. 0<y > m=. <.0.5+2^.y > t=. (<:%>:) (x:!.0 y)%2x^m > if. x<-:#":t do. t=. (1+x) round t end. > ln2=. 2*+/1r3 (^%]) 1+2*i.>.0.5*(%3)^.0.5*0.1^x+>.10^.1>.m > lnr=. 2*+/t (^%]) 1+2*i.>.0.5*(|t)^.0.5*0.1^x > lnr + m * ln2 > ) > > 0j20":ln 2 3 > > 0.69314718055994530942 43.00000000000000000000 > > > Obviously not the ln of 3. This gives the correct answer in J8.07 but is > also wrong in J9.01 . > > > This results in a stack error: > > > add=:(4 : 0)"0 > > echo 'Running add ',":x,y > > x+y > > ) > > p=:DP&$: : (4 : 0) " 0 > > x add y > > ) > > p 2 3 > > |stack error: p > > | p 2 3 > > |[-9] > > JVERSION > > Engine: j902/j64avx2/windows > > Beta-h: commercial/2020-10-03T19:50:26 > > Library: 9.02.06 > > Qt IDE: 1.8.7/5.12.7(5.12.7) > > Platform: Win 64 > > Installer: J902 install > > InstallPath: c:/j902 > > Contact: www.jsoftware.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
