Comparing to zero

[Litvak Vladimir]

Dear Robert and Eric,

Maybe I should explain what I really want to do and then you'll be able to
suggest another solution for me.

I want to compare power between two conditions A and B (dependent
samples). I already tried comparing it the usual way but I want to also
try comparing relative increase (A-B)/B.  This way I have only one dataset
that needs to be compared to zero. If I apply the same transformation to B
I'll get of course just an array of zeros and it doesn't seem right to me
to compare it with the normalized A.

Any ideas? Maybe I should just normalize both by the average 2A/(A+B) and
2B/(A+B) and the compare?

Thanks,

Vladimir