public void ComputeHashTest()
{
int[][] perms = new[] { new[] { 1, 4, 8 }, new[] { 2, 3, 8 }, new[] { 7, 9, 0 } };
permutations.Setup(perm => perm.GetPermutations()).Returns(perms);
byte[] hashed = minHashService.Hash(new TinyFingerprintSchema(10).SetTrueAt(2, 4, 6), perms.Length);
Assert.AreEqual(1, hashed[0]);
Assert.AreEqual(0, hashed[1]);
Assert.AreEqual(255, hashed[2]);
}
public void ComputeHashTest()
{
var perms = new TestPermutations();
var minHashService = new MinHashService(perms);
byte[] hashed = minHashService.Hash(new TinyFingerprintSchema(10).SetTrueAt(2, 4, 6), perms.GetPermutations().Length);
Assert.AreEqual(1, hashed[0]);
Assert.AreEqual(0, hashed[1]);
Assert.AreEqual(255, hashed[2]);
}
public void ComputeHashTest()
{
int[][] perms = new[] { new[] { 1, 4, 8 }, new[] { 2, 3, 8 }, new[] { 7, 9, 0 } };
permutations.Setup(perm => perm.GetPermutations()).Returns(perms);
bool[] fingerprint = new[] { false, false, true, false, true, false, true, false, false, false };
byte[] hashed = minHashService.Hash(fingerprint);
Assert.AreEqual(1, hashed[0]);
Assert.AreEqual(0, hashed[1]);
Assert.AreEqual(255, hashed[2]);
}
public void ShouldNotIdentifyTooManyHashesOnLastPosition()
{
var random = new Random(1);
var permutations = new MaxEntropyPermutations();
var minHash = new MinHashService(permutations);
var counts = new List <int>();
int maxIndex = permutations.GetPermutations().First().Length;
Assert.AreEqual(255, maxIndex);
for (int i = 0; i < 50000; ++i)
{
var schema = TestUtilities.GenerateRandomFingerprint(random, 200, 128, 32);
byte[] hashes = minHash.Hash(schema, 25 * 4);
int count = hashes.Count(last => last == maxIndex);
counts.Add(count);
}
Console.WriteLine($"Avg. Permutations {counts.Average():0.000}");
Console.WriteLine($"Max. {counts.Max()}");
Console.WriteLine($"Min. {counts.Min()}");
Assert.IsTrue(counts.Average() <= 0.25, "On average we expect no more than 0.25 elements in the schema to contain hashes at last position");
}
