ps_trunc.md
In propensity: A Toolkit for Calculating and Working with Propensity Scores

ps_trunc() errors on invalid usage or .exposure

Code
  expr
Condition <propensity_binary_transform_error>
  Error in `ps_trunc()`:
  ! Don't know how to transform `.exposure` to 0/1 binary variable.
  i Specify `.focal_level` and `.reference_level`.

Code
  expr
Condition <propensity_binary_transform_error>
  Error in `ps_trunc()`:
  ! Don't know how to transform `.exposure` to 0/1 binary variable.
  i Specify `.focal_level` and `.reference_level`.

Code
  expr
Condition <propensity_range_error>
  Error in `ps_trunc()`:
  ! `lower` must be smaller than `upper`
  x `lower` is 0.8 and `upper` is 0.3

ps_trunc warns when combining objects with different parameters

Code
  expr
Condition <propensity_coercion_warning>
  Warning in `vec_ptype2.ps_trunc.ps_trunc()`:
  Converting ps_trunc to numeric: different truncation parameters
  i Metadata cannot be preserved when combining incompatible objects
  i Use identical objects or explicitly cast to numeric to avoid this warning