These functions can be used to change the size of a model's fixed effects, its random effect variance/covariance matrices, or its residual variance. This gives you more control over simulations from the model.
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a fitted model object.
new parameter values.
New values for
VarCorr are interpreted as variances and covariances, not standard deviations and
correlations. New values for
scale are interpreted on the standard deviation scale.
This means that both
object unchanged, as you would expect.
sigma<- will only change the residual standard deviation,
scale<- will affect both
These function can be used to change the value of individual parameters, such as a single fixed effect coefficient, using standard R subsetting commands.
getData if you want to modify the model's data.
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