Currently, J's implementation of | for complex numbers is inconsistent with the implementation for reals. Compare:
5 | 0 1 2 3 4 0 1 2 3 4 }: 5 | 0 1 2 3 4,1j1 0 1 2 _2 _1
The definition of complex remainder is in jz.c:
ZF2(jtzrem){D a,b,d;Z q;
if(ZEZ(u))R v;
ZASSERT(!ZINF(v),EVNAN);
if(INF(u.re)&&!u.im&&!v.im){
if(u.re==inf )R 0<=v.re?v:u;
if(u.re==infm)R 0>=v.re?v:u;
}
ZASSERT(!ZINF(u),EVNONCE);
d=u.re*u.re+u.im*u.im;
a=u.re*v.re+u.im*v.im; q.re=tfloor(0.5+a/d);
b=u.re*v.im-u.im*v.re; q.im=tfloor(0.5+b/d);
R zminus(v,ztymes(u,q));
}Changing q.re=tfloor(0.5+a/d); and q.im=tfloor(0.5+b/d) to q.re=tfloor(a/d) and q.im=tfloor(b/d) fixes this behavior.
Note that since complex #: calls complex |, this effects similar changes to antibase.
Contributed by MarshallLochbaum.