That's interesting, Don, ,.((_4+i.7)+n^2x)|5729082486784839 135 146 23 39 147 104 171 ,.((_4+i.7)+n^2)|5729082486784839 0 0 0 0 0 0 0 Linda
Sent from AOL Mobile Mail On Thursday, September 7, 2017 Don Kelly <d...@shaw.ca> wrote: 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
