Thanks. It makes sense, however differences to the order of 2e_14 and smaller usually don't affect my work (money and finance), although here it did. :-)
On Tue, Aug 10, 2021 at 10:25 AM Raul Miller <[email protected]> wrote: > Basically, you're looking at floating point inaccuracy for fractions. > > J uses IEEE754 64 bit binary floating point numbers. > https://en.wikipedia.org/wiki/IEEE_754#. These numbers can represent > fractional powers of 2 exactly, but cannot represent fractional powers > of 5 exactly. > > So, 5^-1 2 3 4 are all represented inexactly, and, thus, 10^-1 2 3 4 > are all represented inexactly. > > You can see this here: > > (*!.0)_0.5+10*1|0.05+i. 10 10 > 0 1 _1 _1 _1 _1 _1 _1 1 1 > 1 1 1 1 1 1 1 1 1 1 > 1 1 1 1 1 1 1 1 1 1 > 1 1 _1 _1 _1 _1 _1 _1 _1 _1 > _1 _1 _1 _1 _1 _1 _1 _1 _1 _1 > _1 _1 _1 _1 _1 _1 _1 _1 _1 _1 > _1 _1 _1 _1 _1 _1 _1 _1 _1 _1 > _1 _1 _1 _1 _1 _1 _1 _1 _1 _1 > _1 _1 _1 _1 _1 _1 _1 _1 _1 _1 > _1 _1 _1 _1 _1 _1 _1 _1 _1 _1 > > I hope this makes sense, > > -- > Raul > > > On Tue, Aug 10, 2021 at 3:34 AM Pablo Landherr <[email protected]> > wrote: > > > > I just came across this result: > > > > 0j1":0.05+i. 10 10 > > > > 0.1 1.1 2.0 3.0 4.0 5.0 6.0 7.0 8.1 9.1 > > > > 10.1 11.1 12.1 13.1 14.1 15.1 16.1 17.1 18.1 19.1 > > > > 20.1 21.1 22.1 23.1 24.1 25.1 26.1 27.1 28.1 29.1 > > > > 30.1 31.1 32.0 33.0 34.0 35.0 36.0 37.0 38.0 39.0 > > > > 40.0 41.0 42.0 43.0 44.0 45.0 46.0 47.0 48.0 49.0 > > > > 50.0 51.0 52.0 53.0 54.0 55.0 56.0 57.0 58.0 59.0 > > > > 60.0 61.0 62.0 63.0 64.0 65.0 66.0 67.0 68.0 69.0 > > > > 70.0 71.0 72.0 73.0 74.0 75.0 76.0 77.0 78.0 79.0 > > > > 80.0 81.0 82.0 83.0 84.0 85.0 86.0 87.0 88.0 89.0 > > > > 90.0 91.0 92.0 93.0 94.0 95.0 96.0 97.0 98.0 99.0 > > > > JVERSION > > > > Engine: j807/j64/darwin > > > > Release-d: commercial/2019-03-18T16:07:14 > > > > Library: 8.07.26 > > > > Qt IDE: 1.7.10/5.9.8 > > > > Platform: Darwin 64 > > > > Installer: J807 install > > > > InstallPath: /applications/j64-807 > > > > Contact: www.jsoftware.com > > > > > > My question: is there a simple explanation to which numbers are rounded > up > > and which are rounded down using ": > > > > > > Kind regards, > > > > Pablo > > ---------------------------------------------------------------------- > > 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
