public void GaussianOpMean()
        {
            Gaussian result     = new Gaussian();
            Gaussian X0         = Gaussian.FromMeanAndVariance(7, 1.0 / 3);
            Gaussian Mean0      = Gaussian.FromMeanAndVariance(3, 0.5);
            Gamma    Precision0 = Gamma.FromShapeAndScale(3, 3);

            // Unknown precision
            Gamma    Precision = Gamma.FromShapeAndScale(3, 3);
            Gaussian X         = X0;
            Gaussian Mean      = Mean0;

            // in matlab: test_t_msg
            result = GaussianOp.MeanAverageConditional_slow(X, Mean, Precision);
            Console.WriteLine(result);
            Assert.True(GaussianOp.MeanAverageConditional_slow(X, Mean, Precision).MaxDiff(new Gaussian(-9.9121, -4.5998)) < 1e-0);

            X         = Gaussian.FromMeanAndVariance(1, 2);
            Mean      = Gaussian.PointMass(0);
            Precision = Gamma.FromShapeAndRate(3, 1);
            Gaussian xPostExpected = Gaussian.FromMeanAndVariance(0.178378819440295, 0.365796599498963);

            Console.WriteLine(GaussianOp.SampleAverageConditional_slow(X, Mean, Precision) * X);
            Assert.True(GaussianOp.SampleAverageConditional_slow(X, Mean, Precision).MaxDiff(xPostExpected / X) < 5e-7);
            Console.WriteLine(GaussianOp_Slow.SampleAverageConditional(X, Mean, Precision) * X);
            Assert.True(GaussianOp_Slow.SampleAverageConditional(X, Mean, Precision).MaxDiff(xPostExpected / X) < 5e-7);
        }
        private void GaussianOpX2(Gaussian mean, Gamma precision)
        {
            Gaussian sample, result, result2;

            sample  = Gaussian.PointMass(2);
            result  = GaussianOp.SampleAverageConditional_slow(sample, mean, precision);
            result2 = GaussianOp_Slow.SampleAverageConditional(sample, mean, precision);
            Console.WriteLine("{0}: {1} {2}", sample, result, result2);
            Assert.True(result.MaxDiff(result2) < 1e-8);
            double prevDiff = double.PositiveInfinity;

            for (int i = 8; i < 30; i++)
            {
                double v = System.Math.Pow(0.1, i);
                sample  = Gaussian.FromMeanAndVariance(2, v);
                result2 = GaussianOp_Slow.SampleAverageConditional(sample, mean, precision);
                double diff = result.MaxDiff(result2);
                Console.WriteLine("{0}: {1} diff={2}", sample, result2, diff.ToString("g4"));
                Assert.True(diff <= prevDiff || diff < 1e-6);
                result2 = GaussianOp.SampleAverageConditional_slow(sample, mean, precision);
                diff    = result.MaxDiff(result2);
                Console.WriteLine("{0}: {1} diff={2}", sample, result2, diff.ToString("g4"));
                Assert.True(diff <= prevDiff || diff < 1e-6);
                prevDiff = diff;
            }
        }
示例#3
0
        internal void StudentIsPositiveTest3()
        {
            double shape     = 1;
            Gamma  precPrior = Gamma.FromShapeAndRate(shape, shape);

            Gaussian meanPrior = Gaussian.PointMass(0);
            Gaussian xB        = Gaussian.Uniform();
            Gaussian xF        = GaussianOp.SampleAverageConditional_slow(xB, meanPrior, precPrior);

            for (int iter = 0; iter < 100; iter++)
            {
                xB = IsPositiveOp.XAverageConditional(true, xF);
                xF = GetConstrainedMessage(xB, meanPrior, precPrior, xF);
            }
            Console.WriteLine("xF = {0} x = {1}", xF, xB * xF);
        }
示例#4
0
        private static Gaussian GetConstrainedMessage1(Gaussian sample, Gaussian mean, Gamma precision, Gaussian to_sample)
        {
            Gaussian sampleMarginal = sample * to_sample;
            double   m1, v1;

            to_sample.GetMeanAndVariance(out m1, out v1);
            double m, v;

            sampleMarginal.GetMeanAndVariance(out m, out v);
            double moment2 = m * m + v;
            // vq < moment2 implies 1/vq > 1/moment2
            // implies 1/v2 > 1/moment2 - to_sample.Precision
            double v2max = 1 / (1 / moment2 - to_sample.Precision);
            double v2min = 1e-2;

            double[] v2s   = EpTests.linspace(v2min, v2max, 100);
            double   p2min = 1 / moment2 - to_sample.Precision;

            if (p2min < 0.0)
            {
                return(to_sample);
            }
            double p2max = sample.Precision * 10;

            double[] p2s        = EpTests.linspace(p2min, p2max, 100);
            Gaussian bestResult = to_sample;
            double   bestScore  = double.PositiveInfinity;

            for (int i = 0; i < p2s.Length; i++)
            {
                double p2 = p2s[i];
                double vq = 1 / (to_sample.Precision + p2);
                double m2 = (System.Math.Sqrt(moment2 - vq) / vq - to_sample.MeanTimesPrecision) / p2;
                // check
                double mq = vq * (to_sample.MeanTimesPrecision + m2 * p2);
                Assert.True(MMath.AbsDiff(mq * mq + vq, moment2) < 1e-10);
                Gaussian sample2 = Gaussian.FromMeanAndPrecision(m2, p2);
                Gaussian result  = GaussianOp.SampleAverageConditional_slow(sample2, mean, precision);
                double   score   = System.Math.Abs(result.MeanTimesPrecision);
                if (score < bestScore)
                {
                    bestScore  = score;
                    bestResult = result;
                }
            }
            return(bestResult);
        }
        public void GaussianOpX()
        {
            Gaussian uniform = Gaussian.Uniform();
            Gaussian X0 = Gaussian.FromMeanAndVariance(3, 0.5);
            Gaussian Mean0 = Gaussian.FromMeanAndVariance(7, 1.0 / 3);
            double   Precision0 = 3;
            Gaussian X, Mean;
            Gamma    Precision, to_precision;
            Gaussian xActual, xExpected;

            bool testImproper = false;

            if (testImproper)
            {
                // Test the case where precisionIsBetween = false
                X            = Gaussian.FromNatural(1, 2);
                Mean         = Gaussian.FromNatural(3, -1);
                Precision    = Gamma.FromShapeAndRate(4, 5);
                to_precision = Gamma.FromShapeAndRate(6, 7);
                xActual      = GaussianOp.SampleAverageConditional(X, Mean, Precision, to_precision);
            }

            X            = Gaussian.FromNatural(-2.7793306963303595, 0.050822473645365768);
            Mean         = Gaussian.FromNatural(-5.9447032851878134E-09, 3.2975231004586637E-204);
            Precision    = Gamma.FromShapeAndRate(318.50907574398883, 9.6226982361933746E+205);
            to_precision = Gamma.PointMass(0);
            xActual      = GaussianOp.SampleAverageConditional(X, Mean, Precision, to_precision);

            X            = Gaussian.FromNatural(0.1559599323109816, 8.5162535450918462);
            Mean         = Gaussian.PointMass(0.57957597647840942);
            Precision    = Gamma.FromShapeAndRate(7.8308812008325587E+30, 8.2854255911709925E+30);
            to_precision = Gamma.FromShapeAndRate(1.4709139487775529, 0.14968339171493822);
            xActual      = GaussianOp.SampleAverageConditional(X, Mean, Precision, to_precision);

            X            = Gaussian.FromNatural(0.15595993233964134, 8.5162535466550349);
            Mean         = Gaussian.PointMass(0.57957597647840942);
            Precision    = Gamma.FromShapeAndRate(3.9206259406339067E+20, 4.1481991194547565E+20);
            to_precision = Gamma.FromShapeAndRate(1.4709139487806249, 0.14968339171413536);
            xActual      = GaussianOp.SampleAverageConditional(X, Mean, Precision, to_precision);

            X            = Gaussian.FromNatural(0.15595993261634511, 8.5162535617468418);
            Mean         = Gaussian.PointMass(0.57957597647840942);
            Precision    = Gamma.FromShapeAndRate(1.825759224425317E+19, 1.9317356258150703E+19);
            to_precision = Gamma.FromShapeAndRate(1.4709139487887679, 0.14968339176002607);
            xActual      = GaussianOp.SampleAverageConditional(X, Mean, Precision, to_precision);

            X            = Gaussian.FromNatural(0.16501264432785923, 9.01);
            Mean         = Gaussian.PointMass(0.57957597647840942);
            Precision    = Gamma.FromShapeAndRate(1.6965139612477539E+21, 1.6965139612889427E+21);
            to_precision = Gamma.FromShapeAndRate(1.4695136363119978, 0.14707291154227081);
            xActual      = GaussianOp.SampleAverageConditional(X, Mean, Precision, to_precision);

            // initialized in a bad place, gets stuck in a flat region
            X            = Gaussian.FromNatural(3.9112579392580757, 11.631097473681082);
            Mean         = Gaussian.FromNatural(10.449696977834144, 5.5617978202886995);
            Precision    = Gamma.FromShapeAndRate(1.0112702817305146, 0.026480506235719053);
            to_precision = Gamma.FromShapeAndRate(1, 0.029622790537514355);
            xActual      = GaussianOp.SampleAverageConditional(X, Mean, Precision, to_precision);

            X         = Gaussian.FromNatural(57788.170908674481, 50207.150004827061);
            Mean      = Gaussian.PointMass(0);
            Precision = Gamma.FromShapeAndRate(19764.051194189466, 0.97190264412377791);
            xActual   = GaussianOp.SampleAverageConditional_slow(X, Mean, Precision);

            // integration bounds should be [-36,4]
            X         = Gaussian.FromNatural(1.696828485456396, 0.71980672726406147);
            Mean      = Gaussian.PointMass(-1);
            Precision = new Gamma(1, 1);
            xActual   = GaussianOp.SampleAverageConditional_slow(X, Mean, Precision);
            xExpected = GaussianOp_Slow.SampleAverageConditional(X, Mean, Precision);
            Assert.True(xExpected.MaxDiff(xActual) < 1e-4);

            X         = new Gaussian(-1.565, 0.8466);
            Mean      = new Gaussian(0.0682, 0.3629);
            Precision = new Gamma(103.2, 0.009786);
            xActual   = GaussianOp.SampleAverageConditional_slow(X, Mean, Precision);
            xExpected = GaussianOp_Slow.SampleAverageConditional(X, Mean, Precision);
            Assert.True(xExpected.MaxDiff(xActual) < 1e-4);

            // Fixed precision
            X    = X0;
            Mean = uniform;
            Assert.True(GaussianOp.SampleAverageConditional(Mean, Precision0).MaxDiff(uniform) < 1e-10);
            Mean = Mean0;
            Assert.True(GaussianOp.SampleAverageConditional(Mean, Precision0).MaxDiff(new Gaussian(Mean.GetMean(), Mean.GetVariance() + 1 / Precision0)) < 1e-10);
            Mean = Gaussian.PointMass(Mean0.GetMean());
            Assert.True(GaussianOp.SampleAverageConditional(Mean, Precision0).MaxDiff(new Gaussian(Mean.GetMean(), 1 / Precision0)) < 1e-10);

            // Uniform precision
            // the answer should always be uniform
            Precision = Gamma.Uniform();
            Assert.True(GaussianOp.SampleAverageConditional_slow(X, Mean, Precision).MaxDiff(uniform) < 1e-10);

            // Unknown precision
            Precision = Gamma.FromShapeAndScale(3, 3);
            // Known X
            X    = Gaussian.PointMass(X0.GetMean());
            Mean = uniform;
            Assert.True(GaussianOp.SampleAverageConditional_slow(X, Mean, Precision).MaxDiff(uniform) < 1e-10);
            // Unknown X
            X    = X0;
            Mean = uniform;
            //Console.WriteLine(XAverageConditional2(result));
            Assert.True(GaussianOp.SampleAverageConditional_slow(X, Mean, Precision).MaxDiff(uniform) < 1e-10);
            X    = X0;
            Mean = Mean0;
            // converge the precision message.  (only matters if KeepLastMessage is set).
            //for (int i = 0; i < 10; i++) GaussianOp.PrecisionAverageConditional(X, Mean, Precision, precisionMessage);
            // in matlab: test_t_msg
            if (GaussianOp.ForceProper)
            {
                Assert.True(GaussianOp.SampleAverageConditional_slow(X, Mean, Precision).MaxDiff(Gaussian.FromNatural(3.1495, 0)) < 1e-4);
            }
            else
            {
                Assert.True(GaussianOp.SampleAverageConditional_slow(X, Mean, Precision).MaxDiff(new Gaussian(-9.9121, -4.5998)) < 1e-4);
            }
            X    = X0;
            Mean = Gaussian.PointMass(Mean0.GetMean());
            // converge the precision message.  (only matters if KeepLastMessage is set).
            //for (int i = 0; i < 10; i++) GaussianOp.PrecisionAverageConditional(X, Mean, Precision, precisionMessage);
            // in matlab: test_t_msg
            if (GaussianOp.ForceProper)
            {
                Assert.True(GaussianOp.SampleAverageConditional_slow(X, Mean, Precision).MaxDiff(Gaussian.FromNatural(2.443, 0)) < 1e-4);
            }
            else
            {
                Assert.True(GaussianOp.SampleAverageConditional_slow(X, Mean, Precision).MaxDiff(new Gaussian(0.81394, -1.3948)) < 1e-4);
            }
            // Uniform X
            X    = uniform;
            Mean = Mean0;
            // converge the precision message.  (only matters if KeepLastMessage is set).
            //for (int i = 0; i < 10; i++) GaussianOp.PrecisionAverageConditional(X, Mean, Precision, precisionMessage);
            Assert.True(GaussianOp.SampleAverageConditional_slow(X, Mean, Precision).MaxDiff(new Gaussian(7, 0.5)) < 1e-10);
            X    = uniform;
            Mean = Gaussian.PointMass(Mean0.GetMean());
            // converge the precision message.  (only matters if KeepLastMessage is set).
            //for (int i = 0; i < 10; i++) GaussianOp.PrecisionAverageConditional(X, Mean, Precision, precisionMessage);
            Assert.True(GaussianOp.SampleAverageConditional_slow(X, Mean, Precision).MaxDiff(new Gaussian(7, 1.0 / 6)) < 1e-10);
        }