This app combines two tasks in a single interface. First, it allows you to explore grocery demand across postcode areas and postcode sectors. Second, it lets you experiment with a chain-based spatial interaction model by adjusting assumptions about distance decay and brand attractiveness.

Please note that the app is hosted on the free tier of the Shinyapps.io service, and I do not pay for additional resources. As a result, computing capacity is limited, and the app may occasionally be slow to load or respond.

If the embedded app does not load properly, you can also open it in a separate tab:

Retail spatial interaction app

Further readings

Related tutorials on this site:

• Introduction to spatial interaction modelling: the core model logic behind the app.
• Part 1: Different distance measures in spatial interaction models: the main options for representing distance and accessibility.
• Part 2: Coordinate systems and Euclidean distance: how straight-line distance is calculated from coordinates.
• Part 3: Network distance, shortest paths, and routing algorithms: how more realistic route-based distance can be understood.

External resources:

• ‘Sorry we do not deliver to your area’: geographical inequalities in online groceries provision: introduces the E-food Desert Index, which is hosted by the HASP data service
• Priority Places for Food Index: another interactive policy-facing map of food access hosted by HASP
• Mapping food access: how neighborhood deprivation shapes healthy food availability in the United Kingdom: recent research linking food access patterns to deprivation and health