Calculate probability vector from sample data
Probability vectors are meant for discrete random variables. Your data is drawn from a continuous distribution. In order to get a probability vector from data, you need to bin it into a normalized histogram. This gets you a probability vector. You probably want to make sure though, that bin center and width for samples from both distributions are the same.

I guess you could use the pdf to calculate the probability vectors too, if you knew the pdfs of the distributions. But if you only have access to data, i.e. samples from the distributions, this is not the case.