This function produces a collection of diagnostic plots for ps objects.
Usage
## S3 method for class 'mnps'
plot(x, plots = "optimize", pairwiseMax = TRUE, figureRows = NULL,
color = TRUE, subset = NULL, treatments = NULL, singlePlot = NULL,
multiPage = FALSE, time = NULL, print = TRUE, ...)
Arguments
x
An mnps 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.
pairwiseMax
If FALSE, the plots for the underlying ps fits
will be returned. Otherwise, pairwise maxima will be returned.
figureRows
The number of rows of figures that should be used. If left as NULL, twang
tries to find a reasonable value.
color
If color = FALSE figures will be gray scale.
subset
Used to restrict which of the stop.methods will be used
in the figure. For example subset = c(1,3) would indicate that the
first and third stop.methods (in alphabetical order of those specified
in the original call to mnps) should be included in the figure.
treatments
Only applicable when pairwiseMax is FALSE and plots 3, 4, and 5.
If left at NULL, panels for all treatment pairs are created. If one level of the treatment
variable is specified, plots comparing that treatment to all others are produced. If two levels are
specified, a comparison for that single pair is produced.
singlePlot
For plot calls that produce multiple plots, specifying an integer value of singlePlot will
return only the corresponding plot. E.g., specifying singlePlot = 2 will return the second plot.
multiPage
When multiple frames of a figure are produced, multiPage = TRUE will print each frame on a different page. This is intended for situations where the graphical output is being saved to a file.
time
For use with iptw.
print
If FALSE, the figure is returned but not printed.
...
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.