Problem solved: 9!:18 '' NB. CT is "normal"
5.68434e_14 (62.1-62.15) = (62.15-62.2) 0 62.1-62.15 _0.05 62.15-62.2 _0.05 9!:(11) 18 62.1-62.15 _0.0499999999999971578 62.15-62.2 _0.0500000000000042633 ...So the answer is: Yes, internal representation is my problem. Thanks, On Sat, Aug 21, 2021 at 5:24 AM Devon McCormick <devon...@gmail.com> wrote: > You can use "showNum" - > > https://code.jsoftware.com/wiki/User:Devon_McCormick/Data/JInternalRepresentation > - to look at J's internal representation of an array, here shown 8 bytes > per row: > showNum 0.05 > 227 0 0 0 0 0 0 0 > 8 0 0 0 0 0 0 0 > 1 0 0 0 0 0 0 0 > 0 0 0 0 0 0 0 0 > 154 153 153 153 153 153 169 63 > > > On Fri, Aug 20, 2021 at 10:53 PM bill lam <bbill....@gmail.com> wrote: > > > You can inspect the bit pattern of 0.05 inside data vs that of real 0.05 > > a.i. 2&(3!:5) 0.5 > > 0 0 0 0 0 0 224 63 > > a.i. 2&(3!:5) {.{.countfreq data > > > > similarly check the bit pattern of the two _0.05 > > > > On Thu, Aug 19, 2021 at 7:25 PM Pablo Landherr <pablo.landh...@gmail.com > > > > wrote: > > > > > Have encountered the following unexpected: > > > > > > #data > > > > > > 6226 > > > > > > #~.data > > > > > > 36 > > > > > > 50{.data > > > > > > 0.05 0 0 0 0 0 0.05 0 0 0 0 0 0 0 0 0 0.25 0.05 0 0 0 0.1 0.05 0 0 0 > 0.2 > > > 0.35 0 0 0 0 0 0.1 0 0 0 0 0 0 0 0.05 0.05 0 0 0 0 0 0 0 > > > > > > countfreq > > > > > > 3 : '(~.y),.#/.~y ' > > > > > > 10{.countfreq data > > > > > > 0.05 1161 > > > > > > 0 2886 > > > > > > 0.25 165 > > > > > > 0.1 371 > > > > > > 0.2 145 > > > > > > 0.35 139 > > > > > > _0.05 119 > > > > > > 0.1 100 > > > > > > _0.05 93 > > > > > > 0.15 317 > > > > > > +/0.25=data > > > > > > 165 > > > > > > NB. Looks fine > > > > > > *+/0.05=data* > > > > > > *0* > > > > > > * NB. What is going on?* > > > > > > 9!:18 '' > > > > > > 5.68434e_14 > > > > > > 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 > > > > > > Two observations: > > > > > > 0) I expected +/0.05=data to yield 1161 > > > > > > 1) _0.05 occurs twice in the first column (print precision etc are all > > > default values) > > > > > > > > > What explains this? > > > > > > > > > Kind regards, > > > > > > Pablo Landherr > > > ---------------------------------------------------------------------- > > > For information about J forums see http://www.jsoftware.com/forums.htm > > > > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > > > > > -- > > Devon McCormick, CFA > > Quantitative Consultant > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
