Define CAR neighbours

Define which values of a categorical variable are to be considered neighbours, when used as a CAR-variable (Conditional AutoRegressive variable) in Reca.

Usage

DefineCarNeighbours(
  processData,
  DefinitionMethod = c("ResourceFile", "StratumPolygon"),
  FileName = character(),
  StratumPolygon,
  UseProcessData = F
)

Arguments

processData: CarNeighbours as returned from this function
DefinitionMethod: 'ResourceFile' or 'StratumPolygon'. See details.
FileName: path to file for resource
StratumPolygon: Definition of spatial strata that neighbours should be calculated for (StratumPolygon).
UseProcessData: If TRUE, bypasses execution of function and returns existing 'processData'

Value

Area Neighbour Definition, see: CarNeighbours.

Details

A CAR-variable (condititional autoregressive variable) in Reca is typically a spatial variable reflecting location of a catch. CarNeighbours defines which values (e.g. areas) are to be considered neighbouts in parameterisation. For spatial variables this is typically configured as geographic neighbours, but other definitions are possible. Geomtric neighbour may be calcuated from StratumPolygon if that is defines a spatial variable, by selecting the appropriate 'DefinitionMethod'.

For DefinitionMethod 'ResourceFile': Definitions are read from a tab separated file with headers. Columns defined as:

Column 1: 'CarValue': Value for the CAR-variable (key)
Column 2: 'Neigbhour': Comma-separated list of neighbours (each should occur in Column 1)

The neighbour definition must be symmetric If a is among the neighbours of b, b must also be among the neighbours of a.

For DefinitionMethod 'StratumPolygon': A CarNeighbours table will be calculated from the provided 'StratumPolygon'. Strata that are geographic neighbours (touching each other) will be considered neighbours. runing time and correctness of calcuation may depend on the quality and complexity of the 'StratumPolygon'.

Usage

Arguments

Value

Details

See also