Wald test
Wald test for testing a linear hypothesis about the parameters of fitted lavaan object.
lavTestWald(object, constraints = NULL, verbose = FALSE)
object |
An object of class |
constraints |
A character string (typically between single quotes) containing one or more equality constraints. See examples for more details. |
verbose |
Logical. If |
The constraints are specified using the "==" operator. Both
the left-hand side and the right-hand side of the equality can contain
a linear combination of model parameters, or a constant (like zero).
The model parameters must be specified by their user-specified labels.
Names of defined parameters (using the ":=" operator) can be
included too.
A list containing three elements: the Wald test statistic (stat), the degrees of freedom (df), and a p-value under the chi-square distribution (p.value).
HS.model <- '
visual =~ x1 + b1*x2 + x3
textual =~ x4 + b2*x5 + x6
speed =~ x7 + b3*x8 + x9
'
fit <- cfa(HS.model, data=HolzingerSwineford1939)
# test 1: test about a single parameter
# this is the 'chi-square' version of the
# z-test from the summary() output
lavTestWald(fit, constraints = "b1 == 0")
# test 2: several constraints
con = '
2*b1 == b3
b2 - b3 == 0
'
lavTestWald(fit, constraints = con)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.