예제 #1
0
        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);
        }
예제 #2
0
        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;
            }
        }
예제 #3
0
        public static Gaussian FindxB(Gaussian xB, Gaussian meanPrior, Gamma precPrior, Gaussian xF)
        {
            Gaussian xB3 = IsPositiveOp.XAverageConditional(true, xF);
            Func <Vector, double> func = delegate(Vector x2)
            {
                Gaussian xB2 = Gaussian.FromMeanAndPrecision(x2[0], System.Math.Exp(x2[1]));
                //Gaussian xF2 = GaussianOp.SampleAverageConditional_slow(xB2, meanPrior, precPrior);
                Gaussian xF2 = GaussianOp_Slow.SampleAverageConditional(xB2, meanPrior, precPrior);
                //Assert.True(xF2.MaxDiff(xF3) < 1e-10);
                //return Math.Pow((xF*xB2).GetMean() - (xF2*xB2).GetMean(), 2) + Math.Pow((xF*xB2).GetVariance() - (xF2*xB2).GetVariance(), 2);
                //return KlDiv(xF2*xB2, xF*xB2) + KlDiv(xF*xB3, xF*xB2);
                //return KlDiv(xF2*xB2, xF*xB2) + Math.Pow((xF*xB3).GetMean() - (xF*xB2).GetMean(),2);
                return(MeanError(xF2 * xB2, xF * xB2) + KlDiv(xF * xB3, xF * xB2));
                //return xF.MaxDiff(xF2);
                //Gaussian q = new Gaussian(0, 0.1);
                //return Math.Pow((xF*q).GetMean() - (xF2*q).GetMean(), 2) + Math.Pow((xF*q).GetVariance() - (xF2*q).GetVariance(), 2);
            };

            double m = xB.GetMean();
            double p = xB.Precision;
            Vector x = Vector.FromArray(m, System.Math.Log(p));

            Minimize2(func, x);
            return(Gaussian.FromMeanAndPrecision(x[0], System.Math.Exp(x[1])));
        }
예제 #4
0
        public static Gaussian FindxF2(Gaussian meanPrior, Gamma precPrior, Gaussian xF)
        {
            Func <Vector, double> func = delegate(Vector x2)
            {
                Gaussian xFt = Gaussian.FromMeanAndPrecision(x2[0], System.Math.Exp(x2[1]));
                Gaussian xB  = IsPositiveOp.XAverageConditional(true, xFt);
                Gaussian xF2 = GaussianOp_Slow.SampleAverageConditional(xB, meanPrior, precPrior);
                return(xFt.MaxDiff(xF2));
            };

            double m = xF.GetMean();
            double p = xF.Precision;
            Vector x = Vector.FromArray(m, System.Math.Log(p));

            Minimize2(func, x);
            return(Gaussian.FromMeanAndPrecision(x[0], System.Math.Exp(x[1])));
        }
예제 #5
0
        public static Gaussian FindxF(Gaussian xB, Gaussian meanPrior, Gamma precPrior, Gaussian xF)
        {
            Gaussian xF3 = GaussianOp_Slow.SampleAverageConditional(xB, meanPrior, precPrior);
            Func <Vector, double> func = delegate(Vector x2)
            {
                Gaussian xF2 = Gaussian.FromMeanAndPrecision(x2[0], System.Math.Exp(x2[1]));
                Gaussian xB2 = IsPositiveOp.XAverageConditional(true, xF2);
                //return (xF2*xB2).MaxDiff(xF2*xB) + (xF3*xB).MaxDiff(xF2*xB);
                //return KlDiv(xF2*xB2, xF2*xB) + KlDiv(xF3*xB, xF2*xB);
                //return KlDiv(xF3*xB, xF2*xB) + Math.Pow((xF2*xB2).GetMean() - (xF2*xB).GetMean(),2);
                return(KlDiv(xF2 * xB2, xF2 * xB) + MeanError(xF3 * xB, xF2 * xB));
            };

            double m = xF.GetMean();
            double p = xF.Precision;
            Vector x = Vector.FromArray(m, System.Math.Log(p));

            Minimize2(func, x);
            //MinimizePowell(func, x);
            return(Gaussian.FromMeanAndPrecision(x[0], System.Math.Exp(x[1])));
        }
예제 #6
0
        public static Gaussian FindxF0(Gaussian xB, Gaussian meanPrior, Gamma precPrior, Gaussian xF)
        {
            Gaussian xF3 = GaussianOp_Slow.SampleAverageConditional(xB, meanPrior, precPrior);
            Func <double, double> func = delegate(double tau2)
            {
                Gaussian xF2 = Gaussian.FromNatural(tau2, 0);
                if (tau2 >= 0)
                {
                    return(double.PositiveInfinity);
                }
                Gaussian xB2 = IsPositiveOp.XAverageConditional(true, xF2);
                //return (xF2*xB2).MaxDiff(xF2*xB) + (xF3*xB).MaxDiff(xF2*xB);
                //return KlDiv(xF2*xB2, xF2*xB) + KlDiv(xF3*xB, xF2*xB);
                //return KlDiv(xF3*xB, xF2*xB) + Math.Pow((xF2*xB2).GetMean() - (xF2*xB).GetMean(), 2);
                return(KlDiv(xF2 * xB2, xF2 * xB) + MeanError(xF3 * xB, xF2 * xB));
            };

            double tau = xF.MeanTimesPrecision;
            double fmin;

            tau = Minimize(func, tau, out fmin);
            //MinimizePowell(func, x);
            return(Gaussian.FromNatural(tau, 0));
        }
예제 #7
0
        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);
        }
예제 #8
0
        internal void StudentIsPositiveTest2()
        {
            GaussianOp.ForceProper = false;
            double   shape     = 1;
            double   mean      = -1;
            Gamma    precPrior = Gamma.FromShapeAndRate(shape, shape);
            Gaussian meanPrior = Gaussian.PointMass(mean);
            double   evExpected;
            Gaussian xExpected = StudentIsPositiveExact(mean, precPrior, out evExpected);

            Gaussian xF2 = Gaussian.FromMeanAndVariance(-1, 1);
            // the energy has a stationary point here (min in both dimensions), even though xF0 is improper
            Gaussian xB0 = new Gaussian(2, 1);

            xF2 = Gaussian.FromMeanAndVariance(-4.552, 6.484);
            //xB0 = new Gaussian(1.832, 0.9502);
            //xB0 = new Gaussian(1.792, 1.558);
            //xB0 = new Gaussian(1.71, 1.558);
            //xB0 = new Gaussian(1.792, 1.5);
            Gaussian xF0 = GaussianOp_Slow.SampleAverageConditional(xB0, meanPrior, precPrior);

            //Console.WriteLine("xB0 = {0} xF0 = {1}", xB0, xF0);
            //Console.WriteLine(xF0*xB0);
            //Console.WriteLine(xF2*xB0);

            xF2 = new Gaussian(0.8651, 1.173);
            xB0 = new Gaussian(-4, 2);
            xB0 = new Gaussian(7, 7);
            if (false)
            {
                xF2 = new Gaussian(mean, 1);
                double[] xs      = EpTests.linspace(0, 100, 1000);
                double[] logTrue = Util.ArrayInit(xs.Length, i => GaussianOp.LogAverageFactor(xs[i], mean, precPrior));
                Normalize(logTrue);
                xF2 = FindxF4(xs, logTrue, xF2);
                xF2 = Gaussian.FromNatural(-0.85, 0);
                xB0 = IsPositiveOp.XAverageConditional(true, xF2);
                Console.WriteLine("xF = {0} xB = {1}", xF2, xB0);
                Console.WriteLine("x = {0} should be {1}", xF2 * xB0, xExpected);
                Console.WriteLine("proj[T*xB] = {0}", GaussianOp_Slow.SampleAverageConditional(xB0, meanPrior, precPrior) * xB0);
                double ev = System.Math.Exp(IsPositiveOp.LogAverageFactor(true, xF2) + GaussianOp_Slow.LogAverageFactor(xB0, meanPrior, precPrior) - xF2.GetLogAverageOf(xB0));
                Console.WriteLine("evidence = {0} should be {1}", ev, evExpected);
                return;
            }
            if (false)
            {
                xF2 = new Gaussian(mean, 1);
                xF2 = FindxF3(xExpected, evExpected, meanPrior, precPrior, xF2);
                xB0 = IsPositiveOp.XAverageConditional(true, xF2);
                Console.WriteLine("xF = {0} xB = {1}", xF2, xB0);
                Console.WriteLine("x = {0} should be {1}", xF2 * xB0, xExpected);
                //double ev = Math.Exp(IsPositiveOp.LogAverageFactor(true, xF2) + GaussianOp.LogAverageFactor_slow(xB0, meanPrior, precPrior) - xF2.GetLogAverageOf(xB0));
                //Console.WriteLine("evidence = {0} should be {1}", ev, evExpected);
                return;
            }
            if (false)
            {
                xF2 = new Gaussian(-2, 10);
                xF2 = FindxF2(meanPrior, precPrior, xF2);
                xB0 = IsPositiveOp.XAverageConditional(true, xF2);
                xF0 = GaussianOp_Slow.SampleAverageConditional(xB0, meanPrior, precPrior);
                Console.WriteLine("xB = {0}", xB0);
                Console.WriteLine("xF = {0} should be {1}", xF0, xF2);
                return;
            }
            if (false)
            {
                xF2 = new Gaussian(-3998, 4000);
                xF2 = new Gaussian(0.8651, 1.173);
                xB0 = new Gaussian(-4, 2);
                xB0 = new Gaussian(2000, 1e-5);
                xB0 = FindxB(xB0, meanPrior, precPrior, xF2);
                xF0 = GaussianOp_Slow.SampleAverageConditional(xB0, meanPrior, precPrior);
                Console.WriteLine("xB = {0}", xB0);
                Console.WriteLine("xF = {0} should be {1}", xF0, xF2);
                return;
            }
            if (false)
            {
                //xF2 = new Gaussian(-7, 10);
                //xF2 = new Gaussian(-50, 52);
                xB0 = new Gaussian(-1.966, 5.506e-08);
                //xF2 = new Gaussian(-3998, 4000);
                xF0 = FindxF(xB0, meanPrior, precPrior, xF2);
                Gaussian xB2 = IsPositiveOp.XAverageConditional(true, xF0);
                Console.WriteLine("xF = {0}", xF0);
                Console.WriteLine("xB = {0} should be {1}", xB2, xB0);
                return;
            }
            if (true)
            {
                xF0 = new Gaussian(-3.397e+08, 5.64e+08);
                xF0 = new Gaussian(-2.373e+04, 2.8e+04);
                xB0 = new Gaussian(2.359, 1.392);
                xF0 = Gaussian.FromNatural(-0.84, 0);
                //xF0 = Gaussian.FromNatural(-0.7, 0);
                for (int iter = 0; iter < 10; iter++)
                {
                    xB0 = FindxB(xB0, meanPrior, precPrior, xF0);
                    Gaussian xFt = GaussianOp_Slow.SampleAverageConditional(xB0, meanPrior, precPrior);
                    Console.WriteLine("xB = {0}", xB0);
                    Console.WriteLine("xF = {0} should be {1}", xFt, xF0);
                    xF0 = FindxF0(xB0, meanPrior, precPrior, xF0);
                    Gaussian xBt = IsPositiveOp.XAverageConditional(true, xF0);
                    Console.WriteLine("xF = {0}", xF0);
                    Console.WriteLine("xB = {0} should be {1}", xBt, xB0);
                }
                Console.WriteLine("x = {0} should be {1}", xF0 * xB0, xExpected);
                double ev = System.Math.Exp(IsPositiveOp.LogAverageFactor(true, xF0) + GaussianOp_Slow.LogAverageFactor(xB0, meanPrior, precPrior) - xF0.GetLogAverageOf(xB0));
                Console.WriteLine("evidence = {0} should be {1}", ev, evExpected);
                return;
            }

            //var precs = EpTests.linspace(1e-6, 1e-5, 200);
            var precs = EpTests.linspace(xB0.Precision / 11, xB0.Precision, 100);

            //var precs = EpTests.linspace(xF0.Precision/20, xF0.Precision/3, 100);
            precs = EpTests.linspace(1e-9, 1e-5, 100);
            //precs = new double[] { xB0.Precision };
            var ms = EpTests.linspace(xB0.GetMean() - 1, xB0.GetMean() + 1, 100);

            //var ms = EpTests.linspace(xF0.GetMean()-1, xF0.GetMean()+1, 100);
            //precs = EpTests.linspace(1.0/10, 1.0/8, 200);
            ms = EpTests.linspace(2000, 4000, 100);
            //ms = new double[] { xB0.GetMean() };
            Matrix result  = new Matrix(precs.Length, ms.Length);
            Matrix result2 = new Matrix(precs.Length, ms.Length);

            //ms = new double[] { 0.7 };
            for (int j = 0; j < ms.Length; j++)
            {
                double   maxZ  = double.NegativeInfinity;
                double   minZ  = double.PositiveInfinity;
                Gaussian maxxF = Gaussian.Uniform();
                Gaussian minxF = Gaussian.Uniform();
                Gaussian maxxB = Gaussian.Uniform();
                Gaussian minxB = Gaussian.Uniform();
                Vector   v     = Vector.Zero(3);
                for (int i = 0; i < precs.Length; i++)
                {
                    Gaussian xF = Gaussian.FromMeanAndPrecision(ms[j], precs[i]);
                    xF = xF2;
                    Gaussian xB = IsPositiveOp.XAverageConditional(true, xF);
                    xB = Gaussian.FromMeanAndPrecision(ms[j], precs[i]);
                    //xB = xB0;
                    v[0] = IsPositiveOp.LogAverageFactor(true, xF);
                    v[1] = GaussianOp.LogAverageFactor_slow(xB, meanPrior, precPrior);
                    //v[1] = GaussianOp_Slow.LogAverageFactor(xB, meanPrior, precPrior);
                    v[2] = -xF.GetLogAverageOf(xB);
                    double logZ = v.Sum();
                    double Z    = logZ;
                    if (Z > maxZ)
                    {
                        maxZ  = Z;
                        maxxF = xF;
                        maxxB = xB;
                    }
                    if (Z < minZ)
                    {
                        minZ  = Z;
                        minxF = xF;
                        minxB = xB;
                    }
                    result[i, j]  = Z;
                    result2[i, j] = IsPositiveOp.LogAverageFactor(true, xF) + xF0.GetLogAverageOf(xB) - xF.GetLogAverageOf(xB);
                    //Gaussian xF3 = GaussianOp.SampleAverageConditional_slower(xB, meanPrior, precPrior);
                    //result[i, j] = Math.Pow(xF3.Precision - xF.Precision, 2);
                    //result2[i, j] = Math.Pow((xF2*xB).Precision - (xF*xB).Precision, 2);
                    //result2[i, j] = -xF.GetLogAverageOf(xB);
                    //Gaussian xF2 = GaussianOp.SampleAverageConditional_slow(xB, Gaussian.PointMass(0), precPrior);
                    Gaussian xMarginal = xF * xB;
                    //Console.WriteLine("xF = {0} Z = {1} x = {2}", xF, Z.ToString("g4"), xMarginal);
                }
                double delta = v[1] - v[2];
                //Console.WriteLine("xF = {0} xB = {1} maxZ = {2} x = {3}", maxxF, maxxB, maxZ.ToString("g4"), maxxF*maxxB);
                //Console.WriteLine("xF = {0} maxZ = {1} delta = {2}", maxxF, maxZ.ToString("g4"), delta.ToString("g4"));
                Console.WriteLine("xF = {0} xB = {1} minZ = {2} x = {3}", minxF, minxB, minZ.ToString("g4"), minxF * minxB);
            }
            //TODO: change path for cross platform using
            using (var writer = new MatlabWriter(@"..\..\..\Tests\student.mat"))
            {
                writer.Write("z", result);
                writer.Write("z2", result2);
                writer.Write("precs", precs);
                writer.Write("ms", ms);
            }
        }