tests/testthat/test-functional-kgram_counts.R

In kgrams: Classical k-gram Language Models

test_that("Correct k-gram counts in simple case: 1", {
        txt <- c("a b b a", "b a b b", "b a b a")
        f <- kgram_freqs(txt, 2, verbose = F)
        
        
        unigrams <- c("a", "b", BOS(), EOS(), UNK())
        bigrams <- outer(unigrams, unigrams, paste)
        test <- vector("integer", 1 + length(unigrams) + length(bigrams))
        names(test)[[1]] <- ""
        names(test)[1 + seq_along(unigrams)] <- unigrams
        names(test)[1 + length(unigrams) + seq_along(bigrams)] <- bigrams
        
        test[[1]] <- 15
        test["a"] <- 5
        test["b"] <- 7
        test[BOS()] <- 3 # Stored for a 2-gram model
        test[EOS()] <- 3
        test[UNK()] <- 0
        test[paste("a", "a")] <- 0
        test[paste("a", "b")] <- 3
        test[paste("a", BOS())] <- 0
        test[paste("a", EOS())] <- 2
        test[paste("a", UNK())] <- 0
        test[paste("b", "a")] <- 4
        test[paste("b", "b")] <- 2
        test[paste("b", BOS())] <- 0
        test[paste("b", EOS())] <- 1
        test[paste("b", UNK())] <- 0
        test[paste(BOS(), "a")] <- 1
        test[paste(BOS(), "b")] <- 2
        test[paste(BOS(), BOS())] <- 0 # Only stored if 3-gram model
        test[paste(BOS(), EOS())] <- 0
        test[paste(BOS(), UNK())] <- 0
        test[paste(EOS(), "a")] <- 0
        test[paste(EOS(), "b")] <- 0
        test[paste(EOS(), BOS())] <- 0
        test[paste(EOS(), EOS())] <- 0
        test[paste(EOS(), UNK())] <- 0
        test[paste(UNK(), "a")] <- 0
        test[paste(UNK(), "b")] <- 0
        test[paste(UNK(), BOS())] <- 0
        test[paste(UNK(), EOS())] <- 0
        test[paste(UNK(), UNK())] <- 0
        
        actual <- query(f, names(test))
        expected <- as.integer(test)
        
        expect_identical(actual, expected)
})

test_that("Correct k-gram counts in simple case: 2", {
        txt <- c("a b c a", "b a b c", "b c b a")
        f <- kgram_freqs(txt, 2, dict = c("a", "b"), verbose = F) # 'c' is UNK
        
        unigrams <- c("a", "b", BOS(), EOS(), UNK())
        bigrams <- outer(unigrams, unigrams, paste)
        test <- vector("integer", 1 + length(unigrams) + length(bigrams))
        names(test)[[1]] <- ""
        names(test)[1 + seq_along(unigrams)] <- unigrams
        names(test)[1 + length(unigrams) + seq_along(bigrams)] <- bigrams
        
        test[[1]] <- 15
        test["a"] <- 4
        test["b"] <- 5
        test[BOS()] <- 3 # Stored for a 2-gram model
        test[EOS()] <- 3
        test[UNK()] <- 3
        test[paste("a", "a")] <- 0
        test[paste("a", "b")] <- 2
        test[paste("a", BOS())] <- 0
        test[paste("a", EOS())] <- 2
        test[paste("a", UNK())] <- 0
        test[paste("b", "a")] <- 2
        test[paste("b", "b")] <- 0
        test[paste("b", BOS())] <- 0
        test[paste("b", EOS())] <- 0
        test[paste("b", UNK())] <- 3
        test[paste(BOS(), "a")] <- 1
        test[paste(BOS(), "b")] <- 2
        test[paste(BOS(), BOS())] <- 0 # Only stored if 3-gram model
        test[paste(BOS(), EOS())] <- 0
        test[paste(BOS(), UNK())] <- 0
        test[paste(EOS(), "a")] <- 0
        test[paste(EOS(), "b")] <- 0
        test[paste(EOS(), BOS())] <- 0
        test[paste(EOS(), EOS())] <- 0
        test[paste(EOS(), UNK())] <- 0
        test[paste(UNK(), "a")] <- 1
        test[paste(UNK(), "b")] <- 1
        test[paste(UNK(), BOS())] <- 0
        test[paste(UNK(), EOS())] <- 1
        test[paste(UNK(), UNK())] <- 0
        
        actual <- query(f, names(test))
        expected <- as.integer(test)
        
        expect_identical(actual, expected)
})