ip would be best implemented as ip=: * * <.@|
as it would return an integer result. Louis > On 06 Aug 2017, at 12:17, Skip Cave <s...@caveconsulting.com> wrote: > > All, Thanks for the help. > > Here's some real numbers from a problem I'm working on: > Calculate some values from this equation: > v=:2%(3r19-%1 2 3 245 246 247 248) > v > _2.375 _5.84615 _11.4 13.0028 13.0014 13 12.9986 > Raul's first suggestion: > 1|v > 0.625 0.153846 0.6 0.0027933 0.00139082 0 0.998621 > More precision, but signs are wrong on the negative numbers. > > Nolaig's suggestion: > (- <.) v > 0.625 0.153846 0.6 0.0027933 0.00139082 1.77636e_15 0.998621 > Negative signs are still wrong, and the 6th entry should be zero. Looks > like a compare tolerance problem. > > Pascal's solution: > > 1 (| |)v > > 0.375 0.846154 0.4 0.0027933 0.00139082 0 0.998621 > Still has the negatives wrong. > > Martin's solution: > fp=.**1|| > > fp v > > _0.375 _0.846154 _0.4 0.0027933 0.00139082 0 0.998621 > Negatives are right, zeroes are right. This fractional part verb needs to > be in the documentation as part of the numbers chapter. > > Also the integer part verb: ip=.]-**1|| should be included in the > numbers section as well. > ip v > > _2 _5 _11 13 13 13 12 > > Skip > > Skip Cave > Cave Consulting LLC > > On Sun, Aug 6, 2017 at 6:42 AM, Raul Miller <rauldmil...@gmail.com> wrote: > >> 1&| does work, actually. >> >> And, if you want an offset of -1 on that result when the original >> value was negative, you can use (1&| - 0&>) >> >> Thanks, >> >> -- >> Raul >> >> On Sun, Aug 6, 2017 at 3:19 AM, Martin Kreuzer <i...@airkreuzer.com> >> wrote: >>> In easy steps (and for further reference) ... >>> >>> From these test data (two floats, two integers, different signs), to get >> the >>> fractional parts >>> >>> v=. 2.25 _8.11 16 _3 >>> >>> simply taking the Residue (when dividing by 1) doesn't work (error at >>> negative float position) >>> >>> 1|v >>> 0.25 0.89 0 0 >>> >>> So first get Magnitude >>> >>> | v >>> 2.25 8.11 16 3 >>> >>> then take Residue >>> >>> 1 | (| v) >>> 0.25 0.11 0 0 >>> >>> then get the sign right (see Raul's remark below) >>> >>> (*v) * (1 | | v) >>> 0.25 _0.11 0 0 >>> >>> and put it as verb (fp), written as a fork >>> >>> fp=. * * 1|| >>> fp v >>> 0.25 _0.11 0 0 >>> >>> -M >>> >>> >>> At 2017-08-06 02:14, you wrote: >>> >>>> Eh... but that's wrong. You can't add any integer to 0.542857 to get >>>> _0.542857. >>>> >>>> If you want signed fractions, you'd need something like (*@] * (| |)) >>>> >>>> Thanks, >>>> >>>> -- >>>> Raul >>>> >>>> >>>> On Sat, Aug 5, 2017 at 10:01 PM, 'Pascal Jasmin' via Programming >>>> <programm...@jsoftware.com> wrote: >>>>> combining other answers we get the cute: >>>> >>>>> 1 (| |) _0.542857 _1.1875 1.96552 2.92308 4.13043 5.7 7.82353 10.8571 >>>>> 15.5455 23.75 >>>> >>>> >>>> >>>> >>>>> ________________________________ >>>>> From: Bill <bbill....@gmail.com> >>>>> To: "programm...@jsoftware.com" <programm...@jsoftware.com> >>>>> Sent: Saturday, August 5, 2017 8:30 PM >>>>> Subject: Re: [Jprogramming] Fractional parts >>>> >>>> >>>> >>>>> this also depends on what do you expect for negative numbers. >>>> >>>>> Sent from my iPhone >>>> >>>>> On 6 Aug, 2017, at 7:35 AM, Skip Cave <s...@caveconsulting.com> >> wrote: >>>> >>>>>> Oops! i meant: >>>>>> >>>>>> How does one find the fractional parts of a vector of floating point >>>>>> numbers? >>>>>> >>>>>> 0.542857 1.1875 1.96552 2.92308 4.13043 5.7 7.82353 10.8571 15.5455 >>>>>> 23.75 >>>>>> 41.8 114 247 >>>>>> >>>>>> i want: >>>>>> 0.542857 0.1875 0.96552 0.92308 0.13043 0.7 0.82353 0.8571 5.5455 >> 0.75 >>>>>> 0.8 >>>>>> 0 0 >>>>>> >>>>>> (Last two integers have zero fractional part.) >>>>>> >>>>>> >>>>>> Skip Cave >>>>>> Cave Consulting LLC >>>>>> >>>>>> On Sat, Aug 5, 2017 at 6:30 PM, Skip Cave <s...@caveconsulting.com> >>>>>> wrote: >>>>>> >>>>>>> How does one find the fractional parts of a vector of floating point >>>>>>> numbers? >>>>>>> >>>>>>> 0.542857 1.1875 1.96552 2.92308 4.13043 5.7 7.82353 10.8571 15.5455 >>>>>>> 23.75 >>>>>>> 41.8 114 247 >>>>>>> >>>>>>> i want: >>>>>>> 0.542857 0.1875 0.96552 0.92308 0.13043 0.7 0.82353 0.8571 5.5455 >> 0.75 >>>>>>> 0.8 >>>>>>> 114 247 >>>>>>> >>>>>>> Skip >>>>>>> >>>>>>> Skip Cave >>>>>>> Cave Consulting LLC >>>>>> ------------------------------------------------------------ >> ---------- >>>>>> 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 >> ---------------------------------------------------------------------- >> 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
