Confidence Interval for Delta_Med in a 'delta_med'-Class Object
Confidence Interval for Delta_Med in a 'delta_med'-Class Object
Return the confidence interval of the Delta_Med in the output of delta_med().
## S3 method for class 'delta_med'confint(object, parm, level =NULL, boot_type,...)
Arguments
object: The output of delta_med().
parm: Not used because only one parameter, the Delta_Med, is allowed.
level: The level of confidence, default is NULL and the level used when the object was created will be used.
boot_type: If bootstrap confidence interval is to be formed, the type of bootstrap confidence interval. The supported types are "perc" (percentile bootstrap confidence interval, the recommended method) and "bc"
(bias-corrected, or BC, bootstrap confidence interval). If not supplied, the stored boot_type will be used.
...: Optional arguments. Ignored.
Returns
A one-row matrix of the confidence interval. All values are NA if bootstrap confidence interval was not requested when calling delta_med().
Details
It returns the nonparametric bootstrap percentile confidence interval of Delta_Med, proposed byLiu, Yuan, and Li (2023). The object must be the output of delta_med(), with bootstrap confidence interval requested when calling delta_med(). However, the level of confidence can be different from that used when call delta_med().
Examples
library(lavaan)dat <- data_med
mod <-"
m ~ x
y ~ m + x
"
fit <- sem(mod, dat)# Call do_boot() to generate# bootstrap estimates# Use 2000 or even 5000 for R in real studies# Set parallel to TRUE in real studies for faster bootstrappingboot_out <- do_boot(fit, R =45, seed =879, parallel =FALSE, progress =FALSE)# Remove 'progress = FALSE' in practicedm_boot <- delta_med(x ="x", y ="y", m ="m", fit = fit, boot_out = boot_out, progress =FALSE)dm_boot
confint(dm_boot)