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Confidence intervals for squared partial correlation coefficients are generated using the PCorNB() function from the betaNB package. In this example, we use the data set and the model used in betaNB: Example Using the BetaNB Function.

df <- betaNB::nas1982

Regression

Fit the regression model using the lm() function.

object <- lm(QUALITY ~ NARTIC + PCTGRT + PCTSUPP, data = df)

Nonparametric Bootstrap

nb <- NB(object)

Squared Partial Correlation Coefficients

Normal-Theory Approach

out <- PCorNB(nb, alpha = 0.05)

Methods

summary

Summary of the results of PCorNB().

Percentile Confidence Intervals

summary(out, type = "pc")
#> Call:
#> PCorNB(object = nb, alpha = 0.05)
#> 
#> Squared partial correlations
#> type = "pc"
#>            est     se    R   2.5%  97.5%
#> NARTIC  0.4874 0.0975 5000 0.2831 0.6711
#> PCTGRT  0.3757 0.1072 5000 0.1673 0.5832
#> PCTSUPP 0.2254 0.1165 5000 0.0396 0.4868

Bias Corrected Confidence Intervals

summary(out, type = "bc")
#> Call:
#> PCorNB(object = nb, alpha = 0.05)
#> 
#> Squared partial correlations
#> type = "bc"
#>            est     se    R   2.5%  97.5%
#> NARTIC  0.4874 0.0975 5000 0.2645 0.6536
#> PCTGRT  0.3757 0.1072 5000 0.1528 0.5739
#> PCTSUPP 0.2254 0.1165 5000 0.0380 0.4833

Bias Corrected and Accelerated Confidence Intervals

summary(out, type = "bca")
#> Call:
#> PCorNB(object = nb, alpha = 0.05)
#> 
#> Squared partial correlations
#> type = "bca"
#>            est     se    R   2.5%  97.5%
#> NARTIC  0.4874 0.0975 5000 0.2647 0.6539
#> PCTGRT  0.3757 0.1072 5000 0.1595 0.5761
#> PCTSUPP 0.2254 0.1165 5000 0.0249 0.4566

coef

Return the vector of estimates.

coef(out)
#>    NARTIC    PCTGRT   PCTSUPP 
#> 0.4874382 0.3757383 0.2253739

vcov

Return the sampling covariance matrix.

vcov(out)
#>              NARTIC       PCTGRT      PCTSUPP
#> NARTIC  0.009501545 0.0017829824 0.0019363288
#> PCTGRT  0.001782982 0.0114957825 0.0008931868
#> PCTSUPP 0.001936329 0.0008931868 0.0135608335

confint

Return confidence intervals.

Percentile Confidence Intervals

confint(out, level = 0.95, type = "pc")
#>              2.5 %    97.5 %
#> NARTIC  0.28312605 0.6710505
#> PCTGRT  0.16732226 0.5832476
#> PCTSUPP 0.03959784 0.4867931

Bias Corrected Confidence Intervals

confint(out, level = 0.95, type = "bc")
#>              2.5 %    97.5 %
#> NARTIC  0.26449231 0.6536167
#> PCTGRT  0.15276457 0.5738520
#> PCTSUPP 0.03801282 0.4833138

Bias Corrected and Accelerated Confidence Intervals

confint(out, level = 0.95, type = "bca")
#>              2.5 %    97.5 %
#> NARTIC  0.26469919 0.6538725
#> PCTGRT  0.15952219 0.5760846
#> PCTSUPP 0.02485843 0.4565859

References