unstr {brms} | R Documentation |
Set up an unstructured (UNSTR) correlation term in brms. The function does not evaluate its arguments – it exists purely to help set up a model with UNSTR terms.
unstr(time, gr)
time |
An optional time variable specifying the time ordering of the observations. By default, the existing order of the observations in the data is used. |
gr |
An optional grouping variable. If specified, the correlation structure is assumed to apply only to observations within the same grouping level. |
An object of class 'unstr_term'
, which is a list
of arguments to be interpreted by the formula
parsing functions of brms.
## Not run:
# add an unstructured correlation matrix for visits within the same patient
fit <- brm(count ~ Trt + unstr(visit, patient), data = epilepsy)
summary(fit)
## End(Not run)