
TESTS FOR SHIFT ALTERNATIVES 117
We also can use simulation to determine bands. In contrast to the one-sample case we do not
have a given distribution from which to simulate. Under the hypothesis that the distributions
F and G do not differ for independent observations the joined vector (X
1
, . . . , X
n
, Y
1
, . . . , Y
m
)
is the vector of n + m independent random numbers with identical distribution F = G. Given
a data set, this relation can be used for simulation. Using a permutation π of the indices from
the vector Z = (X
1
, . . . , X
n
, Y
1
, . . . , Y
m
) a new vector Z
0
with Z
0
i
= Z
π(i)
is generated. The
first n components are used as simulated values (X
0
i