Check that the levels of two factors are the same — vec_check

Checks if object and expected have the same levels. If the levels differ

vec_check_levels() returns a list describing the problem
vec_grade_levels() returns a failing grade and informative message with gradethis::fail()

Usage

vec_check_levels(object = .result, expected = .solution, env = parent.frame())

vec_grade_levels(
  object = .result,
  expected = .solution,
  max_diffs = 3,
  env = parent.frame(),
  ...
)

Arguments

object

An object to be compared to expected.

expected

An object containing the expected result.

env

The environment in which to find .result and .solution.

max_diffs

[numeric(1)]
The maximum number of missing and/or unexpected names to include in an informative failure message. Defaults to 3.

...

Arguments passed on to gradethis::fail

hint: Include a code feedback hint with the failing message? This argument only applies to fail() and fail_if_equal() and the message is added using the default options of give_code_feedback() and maybe_code_feedback(). The default value of hint can be set using gradethis_setup() or the gradethis.fail.hint option.
encourage: Include a random encouraging phrase with random_encouragement()? The default value of encourage can be set using gradethis_setup() or the gradethis.fail.encourage option.

Value

If there are any issues, a list from vec_check_levels() or a gradethis::fail() message from vec_grade_levels(). Otherwise, invisibly returns NULL.

Problems

levels_n: object and expected have a different number of levels.
levels: The object has levels that are not expected, or is missing levels that are expected.
levels_reversed: The levels of object are in the opposite order of expected.
level_order: The levels of object are not in the same order as expected.

Examples

.result <- as.factor(rep_len(letters[1:3], 6))
.solution <- as.factor(rep_len(letters[1:2], 6))
vec_check_levels()
#> <tblcheck problem>
#> Your result should have 2 levels, but it has 3 levels.
#> $ type    : chr "levels_n"
#> $ expected: int 2
#> $ actual  : int 3
vec_grade_levels()
#> <gradethis_graded: [Incorrect]
#>   Your result should have 2 levels, but it has 3 levels.
#> >

.result <- as.factor(letters[1:6])
.solution <- as.factor(letters[21:26])
vec_check_levels()
#> <tblcheck problem>
#> Your result should have levels named `u`, `v`, `w`, and 3 more. Your result should not have levels named `a`, `b`, `c`, or 3 more.
#> $ type      : chr "levels"
#> $ missing   : chr [1:6] "u" "v" "w" "x" ...
#> $ unexpected: chr [1:6] "a" "b" "c" "d" ...
vec_grade_levels()
#> <gradethis_graded: [Incorrect]
#>   Your result should have levels named `u`, `v`, `w`, and 3 more.
#>   Your result should not have levels named `a`, `b`, `c`, or 3
#>   more.
#> >
vec_grade_levels(max_diffs = 5)
#> <gradethis_graded: [Incorrect]
#>   Your result should have levels named `u`, `v`, `w`, `x`, `y`,
#>   and 1 more. Your result should not have levels named `a`, `b`,
#>   `c`, `d`, `e`, or 1 more.
#> >
vec_grade_levels(max_diffs = Inf)
#> <gradethis_graded: [Incorrect]
#>   Your result should have levels named `u`, `v`, `w`, `x`, `y`,
#>   and `z`. Your result should not have levels named `a`, `b`,
#>   `c`, `d`, `e`, or `f`.
#> >