Optionalalternative"two.sided" (default), "less" or "greater"; unambiguous abbreviations are accepted.
OptionaldEffect size d, or "small", "medium", "large".
Optionaln1Number of observations in the first group.
Optionaln2Number of observations in the second group.
OptionalpowerPower of the test.
OptionalsigSignificance level. Default 0.05.
Options for pwrT2nTest. The quantity given as
null(or omitted, exceptsigLevel) is solved for.