splancs (version 2.01-21)

tribble: Diggle-Rowlingson Raised Incidence Model

Description

Fits the Diggle-Rowlingson Raised Incidence Model.

Usage

tribble(ccflag, vars=NULL, alphas=NULL, betas=NULL, rho, 
 which=1:length(alphas), covars=NULL, thetas=NULL, 
 steps=NULL, reqmin=0.001, icount=50, hessian=NULL)

Arguments

ccflag

Case-control flag : a vector of ones and zeroes.

vars

A matrix where vars[i,j] is the distance squared from point i to source j.

alphas

Initial value of the alpha parameters.

betas

Initial value of the beta parameters.

rho

Initial value of the rho parameter.

which

Defines the mapping from sources to parameters.

covars

A matrix of covariates to be modelled as log-linear terms. The element covars[i,j] is the value of covariate j for case/control i.

thetas

Initial values of covariate parameters.

steps

Step sizes for the Nelder-Mead simplex algorithm.

reqmin

Tolerance for simplex algorithm

icount

Iteration count for simplex algorithm

hessian

by default NULL, any other value causes hessian to be computed and returned

Value

• The return value is a list with many components, and class ribfit.
• alphas
  A vector of the alpha parameters at the maximum
• betas
  A vector of the beta values at the maximum
• rho
  The value of rho at the maximum
• logl
  The maximised log-likelihood
• null.logl
  The null log-likelihood
• call
  The function call to tribble
• For further information see Diggle and Rowlingson (1993).

References

Rowlingson, B. and Diggle, P. 1993 Splancs: spatial point pattern analysis code in S-Plus. Computers and Geosciences, 19, 627-655; the original sources can be accessed at: http://www.maths.lancs.ac.uk/~rowlings/Splancs/. See also Bivand, R. and Gebhardt, A. 2000 Implementing functions for spatial statistical analysis using the R language. Journal of Geographical Systems, 2, 307-317.

See Also

triblik, dsquare