jack_mannwhitney: Compute Mann-Whitney log-odds estimates.
In drord: Doubly-Robust Estimators for Ordinal Outcomes

Compute Mann-Whitney log-odds estimates.

jack_mannwhitney(
  treat,
  covar,
  out,
  treat_form,
  out_levels,
  out_form,
  out_model
)

`treat`	A `numeric` vector containing treatment status. Missing values are not allowed unless the corresponding entry in `out` is also missing. Only values of 0 or 1 are treated as actual treatment levels. Any other value is assumed to encode a value for which the outcome is missing and the corresponding outcome value is ignored.
`covar`	A `data.frame` containing the covariates to include in the working proportional odds model.
`out`	A `numeric` vector containing the outcomes. Missing outcomes are allowed.
`treat_form`	The right-hand side of a regression formula for the working model of treatment probability as a function of covariates
`out_levels`	A `numeric` vector containing all ordered levels of the outcome.
`out_form`	The right-hand side of a regression formula for the working proportional odds model. NOTE: THIS FORMULA MUST NOT SUPPRESS THE INTERCEPT.
`out_model`	Which R function should be used to fit the proportional odds model. Options are `"polr"` (from the `MASS` package), "vglm" (from the `VGAM` package), or `"clm"` (from the `ordinal` package).