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
