Ejemplo n.º 1
0
    def test_2DNormalDist_variance(self):
        # prepare data
        U = dists.J(
            [dists.Normal(2.0, .5, -1, 4),
             dists.Normal(1.0, .5, -1, 3)])
        #         U = dists.J([dists.Normal(0.5, .5, -1, 2),
        #                      dists.Normal(0.5, .4, -1, 2)])

        # define linear transformation
        trans = JointTransformation()
        for a, b in U.getBounds():
            trans.add(LinearTransformation(a, b))

        # get a sparse grid approximation
        grid = Grid.createPolyGrid(U.getDim(), 10)
        grid.getGenerator().regular(5)
        gs = grid.getStorage()

        # now refine adaptively 5 times
        p = DataVector(gs.getDimension())
        nodalValues = np.ndarray(gs.getSize())

        # set function values in alpha
        for i in range(gs.getSize()):
            gs.getPoint(i).getStandardCoordinates(p)
            nodalValues[i] = U.pdf(trans.unitToProbabilistic(p.array()))

        # hierarchize
        alpha = hierarchize(grid, nodalValues)

        #         # make positive
        #         alpha_vec = DataVector(alpha)
        #         createOperationMakePositive().makePositive(grid, alpha_vec)
        #         alpha = alpha_vec.array()

        dist = SGDEdist(grid, alpha, bounds=U.getBounds())

        fig = plt.figure()
        plotDensity2d(U)
        fig.show()

        fig = plt.figure()
        plotSG2d(dist.grid,
                 dist.alpha,
                 addContour=True,
                 show_negative=True,
                 show_grid_points=True)
        fig.show()

        print("2d: mean = %g ~ %g" % (U.mean(), dist.mean()))
        print("2d: var = %g ~ %g" % (U.var(), dist.var()))
        plt.show()
Ejemplo n.º 2
0
    def test_1DNormalDist_variance(self):
        # prepare data
        U = dists.Normal(1, 2, -8, 8)
        #         U = dists.Normal(0.5, .2, 0, 1)

        # define linear transformation
        trans = JointTransformation()
        a, b = U.getBounds()
        trans.add(LinearTransformation(a, b))

        # get a sparse grid approximation
        grid = Grid.createPolyGrid(U.getDim(), 10)
        grid.getGenerator().regular(5)
        gs = grid.getStorage()

        # now refine adaptively 5 times
        p = DataVector(gs.getDimension())
        nodalValues = np.ndarray(gs.getSize())

        # set function values in alpha
        for i in range(gs.getSize()):
            gs.getPoint(i).getStandardCoordinates(p)
            nodalValues[i] = U.pdf(trans.unitToProbabilistic(p.array()))

        # hierarchize
        alpha = hierarchize(grid, nodalValues)
        dist = SGDEdist(grid, alpha, bounds=U.getBounds())

        fig = plt.figure()
        plotDensity1d(U,
                      alpha_value=0.1,
                      mean_label="$\mathbb{E}",
                      interval_label="$\alpha=0.1$")
        fig.show()

        fig = plt.figure()
        plotDensity1d(dist,
                      alpha_value=0.1,
                      mean_label="$\mathbb{E}",
                      interval_label="$\alpha=0.1$")
        fig.show()

        print("1d: mean = %g ~ %g" % (U.mean(), dist.mean()))
        print("1d: var = %g ~ %g" % (U.var(), dist.var()))
        plt.show()