The reason for naming the variables as they are seems to be to keep consistency with Vitter's paper [http://www.ittc.ku.edu/~jsv/Papers/Vit87.RandomSampling.pdf

The reason for naming the variables as they are seems to be to keep consistency with Vitter's paper [http://www.ittc.ku.edu/~jsv/Papers/Vit87.RandomSampling.pdf http://www.ittc.ku.edu/~jsv/Papers/Vit87.RandomSampling.pdf] Since the paper is really the primary documentation of the algorithm this makes perfect sense. Renaming the variables to be more meaningful to you would make it harder to compare to the paper, reducing the effectiveness of the paper as documentation and making it hard to compare the code to its specification.