Get the cibound output of a bound from
a semlbci object, the output of semlbci().
Usage
get_cibound(x, row_id, which = c("lbound", "ubound"))Arguments
- x
The output of
semlbci().- row_id
The row number in
x. Should be the number on the left, not the actual row number, because some rows may be omitted in the printout ofx.- which
The bound for which the
ci_bound_wn_i()is to be extracted. Either"lbound"`` or"ubound"``.
Details
It returns the original output of ci_bound_wn_i()
for a bound. Usually for diagnosis.
Author
Shu Fai Cheung https://orcid.org/0000-0002-9871-9448
Examples
library(lavaan)
mod <-
"
m ~ a*x
y ~ b*m
ab := a * b
"
fit_med <- sem(mod, simple_med, fixed.x = FALSE)
p_table <- parameterTable(fit_med)
p_table
#> id lhs op rhs user block group free ustart exo label plabel start est
#> 1 1 m ~ x 1 1 1 1 NA 0 a .p1. 1.676 1.676
#> 2 2 y ~ m 1 1 1 2 NA 0 b .p2. 0.535 0.535
#> 3 3 m ~~ m 0 1 1 3 NA 0 .p3. 34.710 34.710
#> 4 4 y ~~ y 0 1 1 4 NA 0 .p4. 40.119 40.119
#> 5 5 x ~~ x 0 1 1 5 NA 0 .p5. 0.935 0.935
#> 6 6 ab := a*b 1 0 0 0 NA 0 ab 0.000 0.897
#> se
#> 1 0.431
#> 2 0.073
#> 3 3.471
#> 4 4.012
#> 5 0.094
#> 6 0.261
lbci_med <- semlbci(fit_med,
pars = c("ab :="))
lbci_med
#>
#> Results:
#> id lhs op rhs label est lbci_lb lbci_ub lb ub cl_lb cl_ub
#> 6 6 ab := a*b ab 0.897 0.427 1.464 0.385 1.409 0.950 0.950
#>
#> Annotation:
#> * lbci_lb, lbci_ub: The lower and upper likelihood-based bounds.
#> * est: The point estimates from the original lavaan output.
#> * lb, ub: The original lower and upper bounds, extracted from the
#> original lavaan output. Usually Wald CIs for free parameters and
#> delta method CIs for user-defined parameters
#> * cl_lb, cl_ub: One minus the p-values of chi-square difference tests
#> at the bounds. Should be close to the requested level of
#> confidence, e.g., .95 for 95% confidence intervals.
#>
#> Call:
#> semlbci(sem_out = fit_med, pars = c("ab :="))
# Get the output of ci_bound_wn_i() of the lower
# bound of the LBCI for the indirect effect:
get_cibound(lbci_med, row_id = 6, which = "lbound")
#> Target Parameter: ab := a*b (group = 0, block = 0)
#> Position: 6
#> Which Bound: Lower Bound
#> Method: Wu-Neale-2012
#> Confidence Level: 0.95
#> Achieved Level: 0.95000000158432
#> Standardized: No
#> Likelihood-Based Bound: 0.42653
#> Wald Bound: 0.38491
#> Point Estimate: 0.89687
#> Ratio to Wald Bound: 0.9187
#>
#> -- Check --
#> Level achieved? Yes (Difference: 1.5843e-09; Tolerance: 5e-04)
#> Solution admissible? Yes
#> Direction valid? Yes
#>
#> -- Optimization Information --
#> Solver Status: 4
#> Convergence Message: NLOPT_XTOL_REACHED: Optimization stopped because xtol_rel or xtol_abs (above) was reached.
#> Iterations: 11
#> Termination Conditions:
#> xtol_rel: 1e-05
#> ftol_rel: 1e-05
#> maxeval: 500
#>
#> -- Parameter Estimates --
#> a b m~~m y~~y x~~x
#> Start 0.77753 0.49504 35.46538 40.17887 0.93513
#> Final 0.86224 0.49467 35.32975 40.17929 0.93513
#> Change 0.08471 -0.00036 -0.13563 0.00042 0.00000
#>
#> Bound before check: 0.42653
#> Status Code: 0
#> Call: ci_bound_wn_i(i = i, npar = 5L, sem_out = sem_out, f_constr = "<not printed>",
#> which = which, standardized = standardized, wald_ci_start = wald_ci_start,
#> ciperc = 0.95, sf = sf, sf2 = sf2, std_method = std_method_i,
#> debug = FALSE)
#>
# Get the output of ci_bound_wn_i() of the upper
# bound of the LBCI for the indirect effect:
get_cibound(lbci_med, row_id = 6, which = "ubound")
#> Target Parameter: ab := a*b (group = 0, block = 0)
#> Position: 6
#> Which Bound: Upper Bound
#> Method: Wu-Neale-2012
#> Confidence Level: 0.95
#> Achieved Level: 0.950000073477164
#> Standardized: No
#> Likelihood-Based Bound: 1.46404
#> Wald Bound: 1.40883
#> Point Estimate: 0.89687
#> Ratio to Wald Bound: 1.10784
#>
#> -- Check --
#> Level achieved? Yes (Difference: 7.3477e-08; Tolerance: 5e-04)
#> Solution admissible? Yes
#> Direction valid? Yes
#>
#> -- Optimization Information --
#> Solver Status: 3
#> Convergence Message: NLOPT_FTOL_REACHED: Optimization stopped because ftol_rel or ftol_abs (above) was reached.
#> Iterations: 6
#> Termination Conditions:
#> xtol_rel: 1e-05
#> ftol_rel: 1e-05
#> maxeval: 500
#>
#> -- Parameter Estimates --
#> a b m~~m y~~y x~~x
#> Start 2.32329 0.60639 35.10196 40.30883 0.93513
#> Final 2.38407 0.61409 35.10928 40.31234 0.93513
#> Change 0.06077 0.00770 0.00732 0.00352 0.00000
#>
#> Bound before check: 1.46404
#> Status Code: 0
#> Call: ci_bound_wn_i(i = i, npar = 5L, sem_out = sem_out, f_constr = "<not printed>",
#> which = which, standardized = standardized, wald_ci_start = wald_ci_start,
#> ciperc = 0.95, sf = sf, sf2 = sf2, std_method = std_method_i,
#> debug = FALSE)
#>