For what it's worth, left-handed vs. right-handed is not inherently a property of the numbers, but is instead a statement about how the numbers are mapped onto geometry.
We should use a different bit of terminology to describe the sign parity issue. Thanks, -- Raul On Sat, Feb 8, 2020 at 11:34 AM J. Patrick Harrington <[email protected]> wrote: > > Note that the Complete Tensor formula gives a left-handed result, > i.e., x-axis cross y-axis = negative z-axis > > CT =: C.!.2 @ (#:i.) @ $~ > ip=: +/ .* > crossCT=: [ ip CT@#@[ ip ] > 1 0 0 crossCT 0 1 0 > 0 0 _1 > > while > cross=: ((1: |.[)*(_1: |. ]))-((_1: |.[)*(1:|.])) > 1 0 0 cross 0 1 0 > 0 0 1 > > In the physical sciences, we tend to use right handed coordinates. > > Patrick > > On Sat, 8 Feb 2020, Don Guinn wrote: > > > https://code.jsoftware.com/wiki/Essays/Complete_Tensor#cross_product > > > > On Sat, Feb 8, 2020 at 6:07 AM <[email protected]> wrote: > > > >> Dear list, > >> > >> > >> is there a concise way to calculate a cross product of 2 vectors > >> (in 3D, of course). > >> > >> > >> Thanks > >> Ruda > >> ---------------------------------------------------------------------- > >> 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
