next up previous index
Next: The race_names table Up: Database Tables about Households Previous: households_for_estimation ()   Index


The household_characteristics_for_ht table

Bin definitions for the characterizing households used by the Household Transition Model (8.4.9) to produce an N-dimensional partitioning of the households. Thus, the table is only needed if the Household Transition Model is enabled.

The names of the characteristics must match attribute names in the households table (9.11.3). If a characteristic is used in the table annual_household_control_totals (9.11.1), the names in both tables must also match. For example the table can contain the following characteristics:

Characteristic Characteristic Definition Bin Definitions
age_of_head Age, in years, of head of household user-configurable
cars Number of cars in household; must be 0, 1, 2, or 3+ user-configurable
children Number of children in the household user-configurable
income Household income user-configurable
persons Number people in household user-configurable
race_id race_id of head of household user-configurable
workers Number of employed people in household user-configurable

The table has the following structure:

Column Name Data Type Description
characteristic varchar See above for examples
min integer Minimum value for this bin for this characteristic. Values are placed in a bin iff min <= value <= max
max integer Maximum value for this bin for this characteristic; -1 means infinity / no maximum

As an example, this table: defines these bins:
characteristic min max
income 0 4999
income 5000 14999
income 15000 -1
age_of_head 0 -1
children 0 0
children 1 -1
workers 0 0
workers 1 -1
cars 0 0
cars 1 2
cars 3 -1

income:

0..4,999 5,000..14,999 15,000..+infinity

age_of_head:

0..+infinity

children:
0 1..+infinity

workers:
0 1..+infinity

cars:
0 1..2 3..+infinity

The index of these bins within a characteristic is used as a bin number in annual_household_control_totals. This index starts at 0. Thus, using the bins above, a household with two children, a 27 year old head, an income of $6,345, one worker and no cars would be characterized into these bin numbers:

Income: 1
age_of_head: 0
children: 1
workers: 1
cars: 0


next up previous index
Next: The race_names table Up: Database Tables about Households Previous: households_for_estimation ()   Index
info (at) urbansim.org