Plot overlapping density curves of the propensity scores for
both the internal and external participants, or plot external IPWs.

```
prop_scr_dens(
x,
variable = c("propensity score", "ps", "inverse probability weight", "ipw"),
...
)
```

## Arguments

- x
Propensity score object

- variable
Variable to plot. It must be either a propensity score
("ps" or "propensity score") or inverse probability weight ("ipw" or
"inverse probability weight")

- ...
Optional arguments for `geom_density`

## Examples

```
library(dplyr)
ps_obj <- calc_prop_scr(internal_df = filter(int_norm_df, trt == 0),
external_df = ex_norm_df,
id_col = subjid,
model = ~ cov1 + cov2 + cov3 + cov4)
# Plotting the Propensity Scores
prop_scr_dens(ps_obj)
# Or plotting the inverse probability weights
prop_scr_dens(ps_obj, variable = "ipw")
```