Esempio n. 1
0
        public void TestSpace()
        {
            const double eps        = 0.001;
            const double confidence = 0.999;

            const int space  = 2000;
            const int points = 100000;

            const bool randomized = true;

            var random = new Random();
            var spec   = new CountMinSketchSpecHashes(eps, confidence, 123456);
            var state  = CountMinSketchStateHashes.MakeState(spec);

            var sent = new Dictionary <Blob, long?>();

            for (var i = 0; i < points; i++)
            {
                Blob bytes;
                if (randomized)
                {
                    bytes = TestCountMinSketchStateTopK.GenerateBytesRandom(random, space);
                }
                else
                {
                    bytes = TestCountMinSketchStateTopK.GenerateBytesModulo(i, space);
                }
                state.Add(bytes.Data, 1);

                var count = sent.Get(bytes);
                if (count == null)
                {
                    sent.Put(bytes, 1L);
                }
                else
                {
                    sent.Put(bytes, count + 1);
                }

                if (i > 0 && i % 100000 == 0)
                {
                    Console.WriteLine("Completed {0}", i);
                }
            }

            // compare
            var errors = 0;

            foreach (var entry in sent)
            {
                var frequency = state.EstimateCount(entry.Key.Data);
                if (frequency != entry.Value)
                {
                    Console.WriteLine("Expected {0} received {1}", entry.Value, frequency);
                    errors++;
                }
            }
            Console.WriteLine("Found {0} errors at space {1} sent {2}", errors, space, points);
            Assert.IsTrue(eps * points > errors);
        }
Esempio n. 2
0
        public static CountMinSketchState MakeState(CountMinSketchSpec spec)
        {
            CountMinSketchStateHashes hashes = CountMinSketchStateHashes.MakeState(spec.HashesSpec);
            CountMinSketchStateTopk   topk   = null;

            if (spec.TopkSpec != null && spec.TopkSpec > 0)
            {
                topk = new CountMinSketchStateTopk(spec.TopkSpec.Value);
            }
            return(new CountMinSketchState(hashes, topk));
        }
Esempio n. 3
0
        public void TestSimpleFlow()
        {
            var state = CountMinSketchStateHashes.MakeState(GetDefaultSpec());

            Add(state, "hello", 100);
            Assert.AreEqual(100, EstimateCount(state, "hello"));

            Add(state, "text", 1);
            Assert.AreEqual(1, EstimateCount(state, "text"));

            Add(state, "hello", 3);
            Assert.AreEqual(103, EstimateCount(state, "hello"));
            Assert.AreEqual(1, EstimateCount(state, "text"));
        }
Esempio n. 4
0
 private static void Add(CountMinSketchStateHashes state, string item, long count)
 {
     state.Add(GetBytes(item), count);
 }
Esempio n. 5
0
 private static long EstimateCount(CountMinSketchStateHashes state, string item)
 {
     return(state.EstimateCount(GetBytes(item)));
 }
Esempio n. 6
0
 public CountMinSketchState(CountMinSketchStateHashes hashes, CountMinSketchStateTopk topk)
 {
     Hashes = hashes;
     Topk   = topk;
 }