Henry Rich wrote: > More than one post in this thread has conflated 1r_1 with 1j_1 > and I wonder if everyone who is interested (which doesn't > include me) is getting the right meaning out of it. >
The conflation is encouraged by the easiest way to get the angle to (x,y) (or equivalently atan2) in J. arctan=:_3&o. angle =:12&o. For real y, arctan y is the angle between _1r2p1 and 1r2p1 whose tangent is y. For real x and y, angle x+j.y is the angle from the x-axis to (x,y), between _1p1 and 1p1. If x>0, arctan y%x is the same as angle x+j.y, but not if x<:0. When Eldon talks about arctan _1r1 he means angle _1j1. This really has nothing to do with rational numbers, adding to the confusion. Best wishes, John ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
