options(digits = 2)

nums1 <- sample(rep(0:10, time = 5))

nums2 <-
  c(
    rep(1, 7),
    rep(2, 3),
    rep(3, 4),
    rep(4, 5),
    rep(5, 9),
    rep(6, 10),
    rep(7, 8),
    rep(8, 1),
    rep(9, 9),
    rep(10, 4)
  )


# interval
d <- discretize(nums1, method = "interval", breaks = 2)
expect_equal(attr(d, "discretized:breaks"), c(0, 5, 10))

d <- discretize(nums2, method = "interval", breaks = 2)
expect_equal(attr(d, "discretized:breaks"), c(1, 5.5, 10))
expect_equal(as.numeric(table(d)), c(28, 32))

d <- discretize(nums2, method = "interval", breaks = 9)
expect_equal(attr(d, "discretized:breaks"), as.numeric(1:10))

# fixed
expect_error(discretize(nums2, method = "fixed", breaks = 1))
### needs at least 2 values for breaks
d <- discretize(nums2, method = "fixed", breaks = c(0, 5, 10))
expect_equal(length(levels(d)), 2L)
expect_equal(as.numeric(table(d)), c(19, 41))

# frequency
d <- discretize(nums1, method = "frequency", breaks = 2)
expect_equal(length(levels(d)), 2L)
expect_equal(as.numeric(table(d)), c(25, 30))

d <- discretize(nums1, method = "frequency", breaks = 11)
expect_equal(as.numeric(table(d)), rep(5, 11))

d <- discretize(nums2, method = "frequency", breaks = 2)
expect_equal(length(levels(d)), 2L)
expect_equal(as.numeric(table(d)), c(28, 32))

d <- discretize(nums2, method = "frequency", breaks = 6)
expect_equal(as.numeric(table(d)), c(10, 9, 9, 10, 9, 13))

# missing values
nums1[3:5] <- NA
d <- discretize(nums1, method = "interval")
expect_equal(sum(is.na(d)), 3L)
d <- discretize(nums1, method = "frequency")
expect_equal(sum(is.na(d)), 3L)
d <- discretize(nums1, method = "cluster")
expect_equal(sum(is.na(d)), 3L)