No: integers do not automatically get converted to extended precision. Integers simply have sufficient precision for this example.
Thanks, -- Raul On Fri, Sep 8, 2017 at 3:02 AM, Erling Hellenäs <erl...@erlinghellenas.se> wrote: > An integer is auto-converted to extended precision, but not to rational. Yet > Residue seems to be defined for rationals. > > n=.14 > > (n^2x) |5729082486784839 > > 147 > > 3!:0 (n^2x) > > 64 > > 3!:0 (n^2x) |5729082486784839 > > 64 > > > /Erling > > > > Den 2017-09-08 kl. 03:19, skrev Don Kelly: >> >> Yet this works >> >> n=:14 >> >> (n^2x) |5729082486784839 >> >> 147 >> >> >> Don Kelly >> >> On 2017-09-07 11:40 AM, Erling Hellenäs wrote: >>> >>> Hi all ! >>> >>> Case 1: >>> 3!:0 [ (n^2) >>> >>> 8 >>> >>> (n^2) | 5729082486784839 >>> >>> 0 >>> >>> It is non-intuitive that an integer raised to an integer is a float, but >>> I think it is normal. It would be possible with a performance penalty to get >>> an integer result. One problem with that is that it would easily overflow. >>> It would also be possible to have a special operation for this case. >>> When the left argument is a float the right argument has to be converted >>> to a float. It must be assumed that this conversion is intentional, even >>> though it is implicit. >>> >>> Case 2: >>> 3!:0 [ (n^2) >>> >>> 8 >>> >>> (n^2) | 5729082486784839x >>> >>> 0 >>> >>> 3!:0 (n^2) | 5729082486784839x >>> >>> 8 >>> >>> Here the rational seems to be converted to a float and the result is >>> float. Shouldn't we have an error instead of converting rationals to float? >>> >>> Case 3: >>> >>> 3!:0 (x: n^2) >>> >>> 128 >>> >>> (x: n^2) | 5729082486784839 >>> >>> 0 >>> >>> 3!:0 (x: n^2) | 5729082486784839 >>> >>> 128 >>> >>> I have a hard time understanding what happens here. This result seems >>> very peculiar. Is the left and right argument converted to float and the >>> float result converted to rational?! >>> Shouldn't we have an error instead of converting rationals to float? >>> We could not have floats auto-converted to rationals? >>> In this case the integer should be converted to rational and we should >>> get a rational result? >>> >>> It is non-intuitive that (*: n) does not give the same result as (n^2). >>> Maybe once this was decided because of performance reasons. >>> >>> Cheers, >>> >>> Erling Hellenäs >>> >>> On 2017-09-05 18:41, Rob B wrote: >>>> >>>> Could someone explain this please? >>>> >>>> n=.14 >>>> n >>>> 14 >>>> (*: n) | 5729082486784839 >>>> 147 >>>> 196 | 5729082486784839 >>>> 147 >>>> (n^2) | 5729082486784839 >>>> 0 >>>> (n^2) | 5729082486784839x >>>> 0 >>>> (x: n^2) | 5729082486784839 >>>> 0 >>>> (x: n^2) | 5729082486784839x >>>> 147 >>>> >>>> >>>> Regards, Rob Burns >>>> ---------------------------------------------------------------------- >>>> 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 > > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
