plot.ps {twang}

Plots for ps objects

Description

This function produces a collection of diagnostic plots for ps objects.

Usage

## S3 method for class 'ps'
plot(x, plots = "optimize", subset = NULL, color = TRUE, ...)

Arguments

x

A ps object.

plots

An indicator of which type of plot is desired. The options are

• ⁠"optimize" or 1⁠ A plot of the balance criteria as a function of the GBM iteration.

• ⁠"boxplot" or 2⁠ Boxplots of the propensity scores for the treatment and control cases

• ⁠"es" or 3⁠ Plots of the standardized effect size of the pre-treatment variables before and after reweighing

• ⁠"t" or 4⁠ Plots of the p-values from t-statistics comparing means of treated and control subjects for pretreatment variables, before and after weighting.

• ⁠"ks" or 5⁠ Plots of the p-values from Kolmogorov-Smirnov statistics comparing distributions of pretreatment variables of treated and control subjects, before and after weighting.

subset

If multiple stop.method rules were used in the ps() call, subset restricts the plots of a subset of the stopping rules that were employed. This argument expects a subset of the integers from 1 to k, if k stop.methods were used.

color

If color = FALSE, figures will be gray scale. Default: TRUE.

...

Additional arguments.

Details

This function produces lattice-style graphics of diagnostic plots.

References

Dan McCaffrey, G. Ridgeway, Andrew Morral (2004). "Propensity Score Estimation with Boosted Regression for Evaluating Adolescent Substance Abuse Treatment", Psychological Methods 9(4):403-425.

See Also

ps