a=:(0 0, 2 _3 ,: _1 2) a 0 0 2 _3 _1 2 ]b=:1 1,_1 _2,:3 4 1 1 _1 _2 3 4
a(4 :'+/ &.: *:x-y' "1)b NB. Under since Square Root is obverse (inverse) of Square 1.41421 3.16228 4.47214 a((+/ &.: *:)@: -) "1 b NB. in a tacit way 1.41421 3.16228 4.47214 a([: (+/ &.: *:) -) "1 b 1.41421 3.16228 4.47214 a([: +/ &.: *: -) "1 b 1.41421 3.16228 4.47214 a(+/ &.: *:@: -) "1 b 1.41421 3.16228 4.47214 ((+/ &.: *:)@: -) "1 NB. Parentheses help readability but are not needed +/&.:*:@:-"1 a(+/ &.: *:@: - "1 )b 1.41421 3.16228 4.47214 Le 2017-10-27 à 22:48, 'Skip Cave' via Programming a écrit : > Raul, > > Yes, rank was the problem. It hit me while I was eating dinner > but your solution was different than what I expected (they usually are): > > Raul: > > dis =.4 :'%:+/*:x-y' "1 > > (0 0, 2 _3 ,: _1 2) dis 1 1,_1 _2,:3 4 > > 1.41421 3.16228 4.47214 > > > 0 0 dis 1 1,_1 _2,:3 4 > > 1.41421 2.23607 5 > > > I need to study this more. My solution was: > > dis =. 4 :'%:+/"1 *:x-y' > > > (0 0, 2 _3 ,: _1 2) dis 1 1,_1 _2,:3 4 > > 1.41421 3.16228 4.47214 > > > 0 0 dis 1 1,_1 _2,:3 4 > > |length error: dis > > | %:+/"1*:x -y > > > So my scheme doesn't work for one-to-many. It just works on one-to-one > > & many-to-many (both nouns must be the same size). > > I had no idea you could put the rank operator outside the quotes! > > Where does the language description doc discuss this trick? > > > Skip > > Skip Cave > Cave Consulting LLC > > On Fri, Oct 27, 2017 at 7:03 PM, Raul Miller <rauldmil...@gmail.com> wrote: > >> The items that dis is expecting are rank 1 vectors. So it might make >> sense to include a rank 1 specification in its definition: >> >> dis =: 4 :'%:+/*:x-y'"1 >> >> Does that work for this example? >> >> 0 0 dis 1 1,_1 _2,:3 4 >> 1.41421 2.23607 5 >> >> ... seems so ... >> >> Thanks, >> >> -- >> Raul >> >> >> On Fri, Oct 27, 2017 at 7:11 PM, 'Skip Cave' via Programming >> <programm...@jsoftware.com> wrote: >>> In the 2014-11-11 NYCJUG meeting >>> <http://code.jsoftware.com/wiki/NYCJUG/2014-11-11> there was a >> discussion >>> on Euclidean Distance. The verb 'dis' was used to demonstrate how to to >>> calculate the Euclidean distance between two vectors. >>> >>> 0 0 dis 1 1 NB. Euclidean distance 1.41421 1 1,_1 _2,:3 4 NB. Table of >> 2-D >>> points 1 1 _1 _2 3 4 0 0 dis 1 1,_1 _2,:3 4 NB. Distances from origin >>> 1.41421 2.23607 5 0 0 0 dis 1 1 1 NB. Handles higher dimensions 1.73205 >>> I have a NLP project that needs to calculate the >>> Euclidean distance between points in a multi-dimensional >>> space. I now the basic formula - square the differences, >>> sum the squares, take the square root of the sum: >>> >>> dis =. 4 :'%:+/*:x-y' >>> >>> 0 0 dis 1 1 >>> >>> 1.41421 >>> 0 0 0 dis 1 1 1 >>> >>> 1.73205 >>> >>> Looking good.... >>> >>> 0 0 dis 1 1,_1 _2,:3 4 >>> >>> |length error: dis >>> >>> | %:+/*:x -y >>> >>> Ooops! >>> >>> How can I make dis handle multiple pairs of vectors? >>> >>> like: >>> >>> (0 0, 2 _3 ,: _1 2) dis 1 1,_1 _2,:3 4 >>> >>> 1.41421 3.16228 4.47214 >>> >>> 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
