The codispersion map: a graphical tool to visualize the association between two spatial variables

The codispersion coefficient quantifies the association between two spatial processes for a particular direction (spatial lag) on a two‐dimensional space. When this coefficient is computed for many directions, it is useful to display those values on a single graph. In this article, we suggest a graphical tool called a codispersion map to visualize the spatial correlation between two sequences on a plane. We describe how to construct a codispersion map for regular and non‐regular lattices, providing algorithms in both cases. Three numerical examples are given to illustrate how useful this map can be to detect those directions for which the codispersion coefficient attains its maximum and minimum values. We also provide the R code to construct the codispersion map in practice.