1. A method of assessing a signal, the method comprising: sampling the signal from at least two tap points to retrieve a sample set, the at least two tap points adapted to retrieve distinct samples from the signal; retrieving a plurality of such sample sets over time; building an at least two dimensional histogram of the joint probability distribution of the plurality of sample sets; and passing the at least two dimensional histogram to a machine learning algorithm trained to predict a value of at least one characteristic of the signal.