I am doing some research on food deserts, i.e. those places with little or no access to supermarkets. I have a list of x,y co-ordinates for the location of supermarkets as well as an attribute for their size. I also have an output area level shapefile. I want to produce a thematic map of the boundaries coloured by their level of access to a supermarket taking into account both the distance to, and size of, the supermarkets. I would appreciate any help on how to go about doing this!