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Test for the is_ordered.R gist.
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| # Verification of the is_ordered.R solution. | |
| library(testthat) | |
| test.generate.random.sequences = function() { | |
| # generate some random sequence | |
| # | |
| # first: a random walk with a drift of unit increases or stagnation | |
| n = 1000 | |
| root.sequence = c(1, 1 + cumsum(sample(c(0, 1), n, replace = TRUE))) | |
| root.range = range(root.sequence) | |
| # make it still ordered, but no longer increasing | |
| transform.map = sample(1:max(root.sequence)) | |
| sorted.seq = transform.map[root.sequence] | |
| # also create a flawed series: duplicate a value | |
| unsorted.seq = | |
| sample(c(min(root.sequence):(max(root.sequence) - 1), | |
| root.sequence[n %/% 2])) | |
| return(list(sorted = sorted.seq, unsorted = unsorted.seq)) | |
| } | |
| test = function() { | |
| # demo tests | |
| # be reproducible/re-runnable | |
| set.seed(1000) | |
| # easy-to-debug test cases | |
| expect_true(is.ordered.sequence(1)) | |
| expect_true(is.ordered.sequence(1:2)) | |
| expect_false(is.ordered.sequence(c(1, 3, 1))) | |
| expect_true(is.ordered.sequence(1:4)) | |
| expect_true(is.ordered.sequence(rep(1:4, each = 3))) | |
| # tests with more sizeable and trickier input | |
| gen.seq.list = test.generate.random.sequences() | |
| expect_true(is.ordered.sequence(gen.seq.list$sorted)) | |
| expect_false(is.ordered.sequence(gen.seq.list$unsorted)) | |
| } | |
| test() |
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