noinfmodel {dyad}R Documentation

Gottman-Murray Marriage model with No Influence

Description

Fit an autoregressive marriage model to husband and wife, with no influence.

Usage

noinfmodel(observations)

Arguments

observations A data frame with two columns, one for the wife (person 1) and one for the husband (person 2) scores for each unit of time

Details

This function fits a model of marriage where input is a series of discrete observations of the wife (W) and the husband (H). The same model can apply to single-sex couples, in which case the wife should be interpreted as partner 1 and the husband as partner 2.

The model is as follows:

W(t+1) = a0 + a1*W(t)

H(t+1) = b0 + b1*H(t)

Value

noinfmodel returns a list consisting of the results (the parameters fit by the model) for the wife (person 1) and the husband (person 2). Each set of results is an object of class noinfmodel. Although variable names (e.g., a0 and a1) are the same for each object, their values correspond to the model fit to the husband or wife (and are generally different for each spouse). Therefore, a0 and a1 for the husband's results should be interpreted as b0 and b1 in the equation for the husband above. An object of class noinfmodel contains the following parameters.

a0 Initial state
a1 Inertia
ss Sum squared residuals
loglik Log likelihood assuming equal variance of residuals across regimes
nparams Number parameters, assuming unequal variance of residuals across regimes
BIC Bayesian Information Criterion
AIC Akaike's Information Criterion
nt Number of observations
score Vector of partner data (from 1 to nt-1)
influence Vector of influence, calculated using a0 and a1 above

Author(s)

Tara Madhyastha and Ellen Hamaker

References

For a general description of the marriage model and influence functions, see Gottman, J. M., Murray, J. D., Swanson, C., Tyson, R., & Swanson, K. R. (2003). The Mathematics of Marriage: Dynamic Nonlinear Models. The MIT Press.

The method of parameter estimation used here is described in Hamaker, E., Zhang, Z., Van der Maas, H.L. Using threshold autoregressive models to study dyadic interactions. Psychometrika, in press.

See Also

linmodel, ojivemodel, combimodel, origmodel,bilinmodel

Examples


require(dyad)
data(couple)
## fit a model with no influence
fit <- noinfmodel(couple)


[Package dyad version 1.0 Index]