Using attributes to calculate density
Sometimes points represent
populations or the number of occurrences at a particular location. For example,
the number of people in a village or the number of thefts at
convenience stores are attributes that are assigned to points. Instead
of calculating the density of the points, you can also calculate the density of
the populations or events that those points represent.
The cell values for a
kernel density surface are determined by finding the sum of attribute values in
overlapping kernels. In this case, a math function is applied that goes from
the attribute value at the location of the point to 0 at the neighborhood
boundary.
In both situations, the
population, not the number of occurrences, is distributed throughout the
surface.