[R] Separating out data values

[Mark Carter]

I'm not very good at statistics, but I know enough to be dangerous. I'm completely new to R, having just discovered it yesterday. Now that the introductions are out of the way ...

I have a table with three columns, only two of which are relevant to the discussion: roe0 and roe1. Plotting roe0 against roe1 shows that there is a convincing correlation between them, and is confirmed by the correlation coefficient. So far, so good. What I'd like to do is answer the question: what is the probability that roe1 is above the median (of roe1) given that roe0 is above the median (of roe0). Is there a simple way of doing this in R?