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Doccing and testing for D dimensional input (not multiple dimensional Y yet)
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2 changed files with 37 additions and 28 deletions
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@ -48,9 +48,9 @@ class StudentT(NoiseDistribution):
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\\ln p(y_{i}|f_{i}) = \\ln \\Gamma(\\frac{v+1}{2}) - \\ln \\Gamma(\\frac{v}{2})\\sqrt{v \\pi}\sigma - \\frac{v+1}{2}\\ln (1 + \\frac{1}{v}\\left(\\frac{y_{i} - f_{i}}{\\sigma}\\right)^2
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:param y: data
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:type y: NxD matrix
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:type y: Nx1 matrix
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:param f: latent variables f
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:type f: NxD matrix
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:type f: Nx1 matrix
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:param extra_data: extra_data which is not used in student t distribution - not used
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:returns: likelihood evaluated for this point
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:rtype: float
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@ -73,12 +73,12 @@ class StudentT(NoiseDistribution):
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\\frac{d \\ln p(y_{i}|f_{i})}{df} = \\frac{(v+1)(y_{i}-f_{i})}{(y_{i}-f_{i})^{2} + \\sigma^{2}v}
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:param y: data
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:type y: NxD matrix
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:type y: Nx1 matrix
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:param f: latent variables f
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:type f: NxD matrix
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:type f: Nx1 matrix
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:param extra_data: extra_data which is not used in student t distribution - not used
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:returns: gradient of likelihood evaluated at points
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:rtype: 1xN array
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:rtype: Nx1 array
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"""
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assert y.shape == f.shape
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@ -95,12 +95,12 @@ class StudentT(NoiseDistribution):
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\\frac{d^{2} \\ln p(y_{i}|f_{i})}{d^{2}f} = \\frac{(v+1)((y_{i}-f_{i})^{2} - \\sigma^{2}v)}{((y_{i}-f_{i})^{2} + \\sigma^{2}v)^{2}}
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:param y: data
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:type y: NxD matrix
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:type y: Nx1 matrix
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:param f: latent variables f
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:type f: NxD matrix
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:type f: Nx1 matrix
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:param extra_data: extra_data which is not used in student t distribution - not used
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:returns: Diagonal of hessian matrix (second derivative of likelihood evaluated at points f)
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:rtype: 1xN array
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:rtype: Nx1 array
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.. Note::
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Will return diagonal of hessian, since every where else it is 0, as the likelihood factorizes over cases
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@ -119,12 +119,12 @@ class StudentT(NoiseDistribution):
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\\frac{d^{3} \\ln p(y_{i}|f_{i})}{d^{3}f} = \\frac{-2(v+1)((y_{i} - f_{i})^3 - 3(y_{i} - f_{i}) \\sigma^{2} v))}{((y_{i} - f_{i}) + \\sigma^{2} v)^3}
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:param y: data
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:type y: NxD matrix
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:type y: Nx1 matrix
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:param f: latent variables f
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:type f: NxD matrix
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:type f: Nx1 matrix
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:param extra_data: extra_data which is not used in student t distribution - not used
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:returns: third derivative of likelihood evaluated at points f
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:rtype: 1xN array
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:rtype: Nx1 array
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"""
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assert y.shape == f.shape
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e = y - f
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@ -138,15 +138,17 @@ class StudentT(NoiseDistribution):
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Gradient of the log-likelihood function at y given f, w.r.t variance parameter (t_noise)
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.. math::
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\\frac{d \\ln p(y_{i}|f_{i})}{d\\sigma^{2}} = -\\frac{1}{\\sigma} + \\frac{(1+v)(y_{i}-f_{i})^2}{\\sigma^3 v(1 + \\frac{1}{v}(\\frac{(y_{i} - f_{i})}{\\sigma^2})^2)}
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\\frac{d \\ln p(y_{i}|f_{i})}{d\\sigma^{2}} = \\frac{v((y_{i} - f_{i})^{2} - \\sigma^{2})}{2\\sigma^{2}(\\sigma^{2}v + (y_{i} - f_{i})^{2})}
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-\\frac{1}{\\sigma} + \\frac{(1+v)(y_{i}-f_{i})^2}{\\sigma^3 v(1 + \\frac{1}{v}(\\frac{(y_{i} - f_{i})}{\\sigma^2})^2)}
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:param y: data
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:type y: NxD matrix
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:type y: Nx1 matrix
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:param f: latent variables f
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:type f: NxD matrix
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:type f: Nx1 matrix
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:param extra_data: extra_data which is not used in student t distribution - not used
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:returns: derivative of likelihood evaluated at points f w.r.t variance parameter
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:rtype: 1x1 array
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:rtype: float
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"""
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assert y.shape == f.shape
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e = y - f
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@ -162,12 +164,12 @@ class StudentT(NoiseDistribution):
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\\frac{d}{d\\sigma^{2}}(\\frac{d \\ln p(y_{i}|f_{i})}{df}) = \\frac{-2\\sigma v(v + 1)(y_{i}-f_{i})}{(y_{i}-f_{i})^2 + \\sigma^2 v)^2}
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:param y: data
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:type y: NxD matrix
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:type y: Nx1 matrix
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:param f: latent variables f
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:type f: NxD matrix
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:type f: Nx1 matrix
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:param extra_data: extra_data which is not used in student t distribution - not used
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:returns: derivative of likelihood evaluated at points f w.r.t variance parameter
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:rtype: 1xN array
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:rtype: Nx1 array
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"""
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assert y.shape == f.shape
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e = y - f
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@ -178,7 +180,16 @@ class StudentT(NoiseDistribution):
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"""
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Gradient of the hessian (d2lik_d2f) w.r.t sigma parameter (standard deviation)
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$$\frac{d}{d\sigma}(\frac{d^{2}p(y_{i}|f_{i})}{d^{2}f}) = \frac{2\sigma v(v + 1)(\sigma^2 v - 3(y-f)^2)}{((y-f)^2 + \sigma^2 v)^3}$$
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.. math::
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\\frac{d}{d\\sigma^{2}}(\\frac{d^{2} \\ln p(y_{i}|f_{i})}{d^{2}f}) = \\frac{2\\sigma v(v + 1)(\\sigma^2 v - 3(y-f)^2)}{((y-f)^2 + \\sigma^2 v)^3}
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:param y: data
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:type y: Nx1 matrix
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:param f: latent variables f
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:type f: Nx1 matrix
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:param extra_data: extra_data which is not used in student t distribution - not used
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:returns: derivative of hessian evaluated at points f and f_j w.r.t variance parameter
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:rtype: Nx1 array
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"""
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assert y.shape == f.shape
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e = y - f
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@ -216,7 +227,6 @@ class StudentT(NoiseDistribution):
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#However the variance of the student t distribution is not dependent on f, only on sigma and the degrees of freedom
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true_var = sigma**2 + self.variance
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print true_var
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return true_var
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def _predictive_mean_analytical(self, mu, var):
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@ -65,16 +65,16 @@ def dparam_checkgrad(func, dfunc, params, args, constrain_positive=True, randomi
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class LaplaceTests(unittest.TestCase):
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def setUp(self):
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self.N = 5
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self.D = 1
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self.X = np.random.rand(self.N, self.D)
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self.D = 3
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self.X = np.random.rand(self.N, self.D)*10
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self.real_std = 0.1
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noise = np.random.randn(*self.X.shape)*self.real_std
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self.Y = np.sin(self.X*2*np.pi) + noise
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noise = np.random.randn(*self.X[:, 0].shape)*self.real_std
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self.Y = (np.sin(self.X[:, 0]*2*np.pi) + noise)[:, None]
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#self.Y = np.array([[1.0]])#np.sin(self.X*2*np.pi) + noise
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self.var = 0.2
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self.f = np.random.rand(self.N, self.D)
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self.f = np.random.rand(self.N, 1)
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#self.f = np.array([[3.0]])#np.sin(self.X*2*np.pi) + noise
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self.var = np.random.rand(1)
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@ -109,6 +109,8 @@ class LaplaceTests(unittest.TestCase):
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grad.checkgrad(verbose=1)
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self.assertTrue(grad.checkgrad())
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""" Gradchecker fault """
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@unittest.expectedFailure
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def test_gaussian_d2lik_d2f_2(self):
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print "\n{}".format(inspect.stack()[0][3])
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self.Y = None
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@ -174,8 +176,6 @@ class LaplaceTests(unittest.TestCase):
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grad.checkgrad(verbose=1)
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self.assertTrue(grad.checkgrad())
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""" Gradchecker fault """
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@unittest.expectedFailure
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def test_studentt_d2lik_d2f(self):
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print "\n{}".format(inspect.stack()[0][3])
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dlik_df = functools.partial(self.stu_t.dlik_df, self.Y)
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@ -224,7 +224,6 @@ class LaplaceTests(unittest.TestCase):
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kernel = GPy.kern.rbf(self.X.shape[1]) + GPy.kern.white(self.X.shape[1])
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gauss_laplace = GPy.likelihoods.Laplace(self.Y.copy(), self.gauss)
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m = GPy.models.GPRegression(self.X, self.Y.copy(), kernel, likelihood=gauss_laplace)
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import ipdb; ipdb.set_trace() # XXX BREAKPOINT
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m.ensure_default_constraints()
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m.randomize()
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m.checkgrad(verbose=1, step=self.step)
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