I have got a data set, it represents the time take taken to get between different nodes on a graph, I have a valid X/Y pair for each node location. The cost of getting between each node is asymmetric, i.e. the cost off getting from A to B is different from getting from B to A.
I am trying to find a way of visualising this data set.
I did think of trying to draw a contour map, but the only methods I have found require a set of spot heights at given locations, when my data set is more like a series of gradients at different locations.