Character containing a regular expression pattern that
describes the parameters that should be included (for keep
) or excluded
(for drop
) in the returned data frame. keep
may also be a
named list of regular expressions. All non-matching parameters will be
removed from the output. If keep
is a character vector, every parameter
name in the "Parameter" column that matches the regular expression in
keep
will be selected from the returned data frame (and vice versa,
all parameter names matching drop
will be excluded). Furthermore, if
keep
has more than one element, these will be merged with an OR
operator into a regular expression pattern like this: "(one|two|three)"
.
If keep
is a named list of regular expression patterns, the names of the
list-element should equal the column name where selection should be
applied. This is useful for model objects where model_parameters()
returns multiple columns with parameter components, like in
model_parameters.lavaan()
. Note that the regular expression pattern
should match the parameter names as they are stored in the returned data
frame, which can be different from how they are printed. Inspect the
$Parameter
column of the parameters table to get the exact parameter
names.