samples = sampler.flatchain

As an AI language model, I do not have access to the context of the code. However, based on my understanding of the term "sampler.flatchain", it is a method used to convert a multi-dimensional array of samples generated by a Monte Carlo sampler into a two-dimensional array. The resulting array contains all the samples from the original array flattened into a single dimension. This can be useful for further analysis and visualization of the samples.