From 6197c1a8edafabe4d347e8cce96977f448cc6b8e Mon Sep 17 00:00:00 2001
From: James Hensman <james.hensman@gmail.com>
Date: Thu, 31 Jan 2013 09:02:18 +0000
Subject: [PATCH] robustified the assertion re lengthscales in rbf

---
 GPy/kern/rbf.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/GPy/kern/rbf.py b/GPy/kern/rbf.py
index 7efbbfe9..1506b323 100644
--- a/GPy/kern/rbf.py
+++ b/GPy/kern/rbf.py
@@ -36,13 +36,15 @@ class rbf(kernpart):
         if not ARD:
             self.Nparam = 2
             if lengthscale is not None:
-                assert lengthscale.size == 1
+                lengthscale = np.asarray(lengthscale)
+                assert lengthscale.size == 1, "Only one lengthscale needed for non-ARD kernel"
             else:
                 lengthscale = np.ones(1)
         else:
             self.Nparam = self.D + 1
             if lengthscale is not None:
-                assert lengthscale.size == self.D
+                lengthscale = np.asarray(lengthscale)
+                assert lengthscale.size == self.D, "bad number of lengthscales"
             else:
                 lengthscale = np.ones(self.D)