From 39eb0368d8880b9a0afe058bbbacee981c4af8a9 Mon Sep 17 00:00:00 2001
From: James Hensman <james.hensman@gmail.com>
Date: Tue, 8 Oct 2013 12:30:14 +0100
Subject: [PATCH] changes Nparts for num_parts in kern

---
 GPy/kern/kern.py            | 12 ++++++------
 GPy/testing/kernel_tests.py | 12 ++++++++++--
 2 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/GPy/kern/kern.py b/GPy/kern/kern.py
index 5a8882dd..d6611a51 100644
--- a/GPy/kern/kern.py
+++ b/GPy/kern/kern.py
@@ -31,7 +31,7 @@ class kern(Parameterized):
 
         """
         self.parts = parts
-        self.Nparts = len(parts)
+        self.num_parts = len(parts)
         self.num_params = sum([p.num_params for p in self.parts])
 
         self.input_dim = input_dim
@@ -61,7 +61,7 @@ class kern(Parameterized):
         here just all the indices, rest can get recomputed
         """
         return Parameterized.getstate(self) + [self.parts,
-                self.Nparts,
+                self.num_parts,
                 self.num_params,
                 self.input_dim,
                 self.input_slices,
@@ -73,7 +73,7 @@ class kern(Parameterized):
         self.input_slices = state.pop()
         self.input_dim = state.pop()
         self.num_params = state.pop()
-        self.Nparts = state.pop()
+        self.num_parts = state.pop()
         self.parts = state.pop()
         Parameterized.setstate(self, state)
 
@@ -308,7 +308,7 @@ class kern(Parameterized):
 
     def K(self, X, X2=None, which_parts='all'):
         if which_parts == 'all':
-            which_parts = [True] * self.Nparts
+            which_parts = [True] * self.num_parts
         assert X.shape[1] == self.input_dim
         if X2 is None:
             target = np.zeros((X.shape[0], X.shape[0]))
@@ -359,7 +359,7 @@ class kern(Parameterized):
     def Kdiag(self, X, which_parts='all'):
         """Compute the diagonal of the covariance function for inputs X."""
         if which_parts == 'all':
-            which_parts = [True] * self.Nparts
+            which_parts = [True] * self.num_parts
         assert X.shape[1] == self.input_dim
         target = np.zeros(X.shape[0])
         [p.Kdiag(X[:, i_s], target=target) for p, i_s, part_on in zip(self.parts, self.input_slices, which_parts) if part_on]
@@ -497,7 +497,7 @@ class kern(Parameterized):
 
     def plot(self, x=None, plot_limits=None, which_parts='all', resolution=None, *args, **kwargs):
         if which_parts == 'all':
-            which_parts = [True] * self.Nparts
+            which_parts = [True] * self.num_parts
         if self.input_dim == 1:
             if x is None:
                 x = np.zeros((1, 1))
diff --git a/GPy/testing/kernel_tests.py b/GPy/testing/kernel_tests.py
index 87d4a20e..71daf0e8 100644
--- a/GPy/testing/kernel_tests.py
+++ b/GPy/testing/kernel_tests.py
@@ -7,6 +7,13 @@ import GPy
 
 verbose = False
 
+try:
+    import sympy
+    SYMPY_AVAILABLE=True
+except ImportError:
+    SYMPY_AVAILABLE=False
+
+
 class KernelTests(unittest.TestCase):
     def test_kerneltie(self):
         K = GPy.kern.rbf(5, ARD=True)
@@ -22,8 +29,9 @@ class KernelTests(unittest.TestCase):
         self.assertTrue(GPy.kern.kern_test(kern, verbose=verbose))
 
     def test_rbf_sympykernel(self):
-        kern = GPy.kern.rbf_sympy(5)
-        self.assertTrue(GPy.kern.kern_test(kern, verbose=verbose))
+        if SYMPY_AVAILABLE:
+            kern = GPy.kern.rbf_sympy(5)
+            self.assertTrue(GPy.kern.kern_test(kern, verbose=verbose))
 
     def test_rbf_invkernel(self):
         kern = GPy.kern.rbf_inv(5)