Multiple outputs model with Gaussian noise

GPy/models/gp_multioutput_regression.py

@@ -0,0 +1,59 @@
+# Copyright (c) 2013, Ricardo Andrade
+# Licensed under the BSD 3-clause license (see LICENSE.txt)
+
+
+import numpy as np
+from ..core import GP
+from .. import likelihoods
+from .. import kern
+from ..util import multioutput
+
+class GPMultioutputRegression(GP):
+    """
+    Multiple output Gaussian process with Gaussian noise
+
+    This is a wrapper around the models.GP class, with a set of sensible defaults
+
+    :param X_list: input observations
+    :type X_list: list of numpy arrays (num_data_output_i x input_dim), one array per output
+    :param Y_list: observed values
+    :type Y_list: list of numpy arrays (num_data_output_i x 1), one array per output
+    :param kernel_list: GPy kernels, defaults to rbf
+    :type kernel_list: list of GPy kernels
+    :param noise_variance_list: noise parameters per output, defaults to 1.0 for every output
+    :type noise_variance_list: list of floats
+    :param normalize_X:  whether to normalize the input data before computing (predictions will be in original scales)
+    :type normalize_X: False|True
+    :param normalize_Y:  whether to normalize the input data before computing (predictions will be in original scales)
+    :type normalize_Y: False|True
+    :param W_columns: number tuples of the corregionalization parameters 'coregion_W' (see coregionalize kernel documentation)
+    :type W_columns: integer
+    """
+
+    def __init__(self,X_list,Y_list,kernel_list=None,noise_variance_list=None,normalize_X=False,normalize_Y=False,W_columns=1):
+
+        self.num_outputs = len(Y_list)
+        assert len(X_list) == self.num_outputs, 'Number of outputs do not match length of inputs list.'
+
+        #Inputs indexing
+        i = 0
+        index = []
+        for x,y in zip(X_list,Y_list):
+            assert x.shape[0] == y.shape[0]
+            index.append(np.repeat(i,x.size)[:,None])
+            i += 1
+        index = np.vstack(index)
+        X = np.hstack([np.vstack(X_list),index])
+        original_dim = X.shape[1] - 1
+
+        #Mixed noise likelihood definition
+        likelihood = likelihoods.Gaussian_Mixed_Noise(Y_list,noise_params=noise_variance_list,normalize=normalize_Y)
+
+        #Coregionalization kernel definition
+        if kernel_list is None:
+            kernel_list = [[kern.rbf(original_dim)],[]]
+        mkernel = multioutput.build_lcm(input_dim=original_dim, num_outputs=self.num_outputs, CK = kernel_list[0], NC = kernel_list[1], W_columns=W_columns)
+
+        self.multioutput = True
+        GP.__init__(self, X, likelihood, mkernel, normalize_X=normalize_X)
+        self.ensure_default_constraints()