Thanks for the reply!
Sorry for my poor understanding but if they are drawn from a multinomial does that mean that there is a random chance a sample will be drawn from a low probability region (like MCMC) or does the method stick to orderly sampling from highest to lowest probability?
Also is there any point in sampling without replacement if it will sample all of the input objects anyway, despite the probabilities, just in a selected order?
I could try num_samples …the only problem then is the overhead time in calculating the number of extra object samples to allow for.