Discrete Objects

Continuous Fields

Discrete Objects

• Distinct boundaries - can be exactly measured
• Finite - countable

Continuous Fields

• No distinct boundaries - everywhere has a value
• Infinitely divisible - not countable

When is a phenomenon discrete or continuous?

• To an extent, it depends on our perspective and the scale of our analysis.
• Many phenomenon are a bit of both.

• A strike is a discrete object
• A lighting bolt ...?
• Strike frequency is a continuous field

• Continuous field at large scale

• Continuous field at large scale
• Discrete object at small scale

• Continuous field at large scale
• Discrete object at small scale
• Unless you change the time scale

That said, it is a helpful framework as long as we recognize the discrete vs. continuous dichotomy is not a perfect classification.

• Concrete Boundaries
• Countable
• Real Physical Object

• Distinct Boundaries
• Countable
• Not a Physical Object

• Everywhere on Earth
• No "number of elevations"
• A physical property

• Everywhere has this too
• Derived from something countable
• Not a physical property

In Module 1, you used discrete data (deaths) to calculate a continuous field (Kernel Density).

In this Module you calculate:

• Average NDVI value (continuous field)
• Within census areas (discrete objects)