Kernels module (turn off redundant variances)

Author: sdatkinson

structured_gpflow/kernels.py

@@ -0,0 +1,24 @@
+# Kernel functions
+# Steven Atkinson
+# satkinso@nd.edu
+# February 21, 2018
+
+import gpflow.kernels
+
+
+def turn_off_variances(kern_list, from_outside=True):
+    """
+    Ensure that we don't have redundant variance parameters to optimize.
+    THIS DOESN'T WORK VERY WELL!  WATCH OUT IF YOUR KERNELS ARE CRAZY!
+    :param kern_list: list of kernels
+    :param top: whether this is the top layer of the kernel (called from outside)
+    :return: (done by reference)
+    """
+
+    if from_outside:
+        kern_list = kern_list[1:]
+    for kern in kern_list:
+        if isinstance(kern, gpflow.kernels.Combination):
+            turn_off_variances(kern.kern_list, False)
+        elif hasattr(kern, "variance"):
+            kern.variance.set_trainable(False)