From 949f3630203defbfb8cc6700e4d11f511282dc62 Mon Sep 17 00:00:00 2001 From: Nicolas Date: Thu, 21 Feb 2013 10:23:18 +0000 Subject: [PATCH] Tutorial update due to some changes in GPy --- doc/tuto_kernel_overview.rst | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/doc/tuto_kernel_overview.rst b/doc/tuto_kernel_overview.rst index 7d76bfdd..c6e15694 100644 --- a/doc/tuto_kernel_overview.rst +++ b/doc/tuto_kernel_overview.rst @@ -28,9 +28,8 @@ should return:: Name | Value | Constraints | Ties ------------------------------------------------------- - rbf_variance | 1.0000 | | - rbf_lengthscale | 1.0000 | | - + rbf_variance | 0.7500 | | + rbf_lengthscale | 2.0000 | | .. figure:: Figures/tuto_kern_overview_basicdef.png :align: center @@ -50,7 +49,12 @@ On the other hand, it is possible to use the `sympy` package to build new kernel Operations to combine kernel ============================ -In ``GPy``, kernel objects can be combined with the usual ``+`` and ``*`` operators. :: +In ``GPy``, two kernel objects can be added or multiplied. In both cases, two kinds of operations are possible since one can assume that the kernels to add/multiply are defined on the same space or on different subspaces. In other words, it is possible to use two kernels :math:`k_1,\ k_2` over :math:`\mathbb{R} \times \mathbb{R}` to create + + * a kernel over :math:`\mathbb{R} \times \mathbb{R}`: :math:`k(x,y) = k_1(x,y) \times k_2(x,y)` + * a kernel over .. :math:`\mathbb{R}^2 \times \mathbb{R}^2`: :math:`k(x,y) = k_1(x_1,y_1) \times k_2(x_2,y_2)` + + multiplied combined with the usual ``+`` and ``*`` operators. :: k1 = GPy.kern.rbf(1,variance=1., lengthscale=2) k2 = GPy.kern.Matern32(1,variance=1., lengthscale=2)