feat: #318 highlight difference between setvaluesto and keepsourcevars

vignettes/programming_strategy.Rmd

@@ -223,9 +223,9 @@ Arguments which only expect one value or variable name must be a singular versio
 | `start_dtc`      | (Partial) start date/datetime in ISO 8601 format.                                                                  |
 | `dtc`            | (Partial) date/datetime in ISO 8601 format.                                                                        |
 | `date`           | Date of an event / interval. Expects a date object.                                                                |
-| `set_values_to`  | List of variable name-value pairs. Use `process_set_values_to()` for processing the value and providing user friendly error messages. |
-| `subject_keys`   | Variables to uniquely identify a subject, defaults to `exprs(STUDYID, USUBJID)`. In function formals, use `subject_keys = get_admiral_option("subject_keys")`                                     |
-| `keep_source_vars` | Specifies which variables from the selected observations should be kept. The default of the argument should be `everything()`.                                          |
+| `subject_keys`   | Variables to uniquely identify a subject, defaults to `exprs(STUDYID, USUBJID)`. In function formals, use `subject_keys = get_admiral_option("subject_keys")`      
+| `set_values_to`  | List of variable name-value pairs. Use `process_set_values_to()` for processing the value and providing user friendly error messages. |                               |
+| `keep_source_vars` | Specifies which variables from the selected observations should be kept. The default of the argument should be `everything()`. The primary difference between `set_values_to` and `keep_source_vars` is that `keep_source_vars` only selects and retains the variables from a source dataset, so e.g. `keep_source_vars = exprs(DOMAIN)` would join + keep the `DOMAIN` variable, whereas `set_values_to` can make renaming and inline function changes such as `set_values_to = exprs(LALVDOM = DOMAIN)`                       |
 | `missing_value`    | A singular value to be entered if the data is missing.                                  |
 | `missing_values`   | A named list of expressions where the names are variables in the dataset and the values are a value to be entered if the data is missing, e.g., `exprs(BASEC = "MISSING", BASE = -1)`.      |