code for visibility grahps, basically a Matlab version of what is proposed here http://www.maths.qmul.ac.uk/~lacasa/Software.html
you should compile the cpp file with mex
then the program is called with
[AD K] = Visibility (timeseries, Vis_type)
where the output is AD = adjacency matrix according to the visibility criterion K = node degree (this is the quantity that is used to compute mutual information)
and the input is timeseries = the time series Vis_type = 1 for Horizontal Visibility and 2 for Natural Visibility