nsdiffsAuto function
Automatic nsdiffs selection: evaluate OCSB and CH together
Implementation
int nsdiffsAuto(List<double> x, int s){
final r1=ocsb(x, s);
final r2=canovaHansen(x, s);
// Simple rule: recommend D=1 if OCSB t < -1.645 or CH > critical ~ 0.269
final ocWant = (!r1.stat.isNaN) && (r1.stat < -1.645);
final chWant = (!r2.stat.isNaN) && (r2.stat > 0.269);
return (ocWant || chWant) ? 1 : 0;
}