public void TestCYK01() {
var productions = new List<Production> {
new Production(
Nonterminal.Of("S"),
new Sentence { Nonterminal.Of("X"), Nonterminal.Of("X") },
2
),
new Production(
Nonterminal.Of("X"),
new Sentence { Nonterminal.Of("X"), Nonterminal.Of("X") },
2
),
new Production(
Nonterminal.Of("S"),
new Sentence { Terminal.Of("a") },
8
),
new Production(
Nonterminal.Of("X"),
new Sentence { Terminal.Of("a") },
8
)
};
var g = new CNFGrammar(productions, Nonterminal.Of("S"));
Helpers.AssertNear(0.8, g.Cyk(Sentence.FromLetters("a")));
Helpers.AssertNear(0.128, g.Cyk(Sentence.FromLetters("aa")));
Helpers.AssertNear(0.04096, g.Cyk(Sentence.FromLetters("aaa")));
Helpers.AssertNear(0.016384, g.Cyk(Sentence.FromLetters("aaaa")));
Helpers.AssertNear(0.007340032, g.Cyk(Sentence.FromLetters("aaaaa")));
}
public void TestHugeWeights() {
var productions = new List<Production> {
CFGParser.Production(@"<S> -> <A> <B> [3000000000]"),
CFGParser.Production(@"<S> -> <C> <A> [3000000000]"),
CFGParser.Production(@"<S> -> ε [3000000000]"),
CFGParser.Production(@"<A> -> 'a'"),
CFGParser.Production(@"<B> -> 'b'"),
CFGParser.Production(@"<C> -> 'c'"),
};
var g = new CNFGrammar(productions, Nonterminal.Of("S"));
Helpers.AssertNear(1.0 / 3.0, g.Cyk(Sentence.FromLetters("")));
Helpers.AssertNear(1.0 / 3.0, g.Cyk(Sentence.FromLetters("ab")));
Helpers.AssertNear(1.0 / 3.0, g.Cyk(Sentence.FromLetters("ca")));
}
public void TestMissingStart02() {
var productions = new List<Production> {
CFGParser.Production(@"<X_0> -> 'a'"),
};
CNFGrammar h = new CNFGrammar(productions, Nonterminal.Of("S"));
Helpers.IsNear(0.0, h.Cyk(Sentence.FromLetters("a")));
}
private static void TestGrammar(CNFGrammar rg)
{
Console.WriteLine("=====================");
for (int i = 0; i < 5; i++)
{
var swps = rg.ProduceToDepth(i);
Console.WriteLine("------Depth {0}------", i);
foreach (var swp in swps)
{
var actual = rg.Cyk(swp.Value);
var expected = swp.Probability;
if (actual < expected)
{
Console.WriteLine("{0}, {1}", actual, expected);
Console.WriteLine(rg);
Console.WriteLine(swp);
}
// Console.WriteLine(swp.Sentence.AsTerminals());
// Console.WriteLine(sentence);
}
}
}
private static void TestGrammar(CNFGrammar rg) {
Console.WriteLine("=====================");
for (int i = 0; i < 5; i++) {
var swps = rg.ProduceToDepth(i);
Console.WriteLine("------Depth {0}------", i);
foreach (var swp in swps) {
var actual = rg.Cyk(swp.Value);
var expected = swp.Probability;
if (actual < expected) {
Console.WriteLine("{0}, {1}", actual, expected);
Console.WriteLine(rg);
Console.WriteLine(swp);
}
// Console.WriteLine(swp.Sentence.AsTerminals());
// Console.WriteLine(sentence);
}
}
}