Added safe_exp and tests

GPy/likelihoods/likelihood.py

@@ -5,7 +5,7 @@ import numpy as np
 from scipy import stats,special
 import scipy as sp
 import link_functions
-from ..util.misc import chain_1, chain_2, chain_3, blockify_dhess_dtheta, blockify_third, blockify_hessian
+from ..util.misc import chain_1, chain_2, chain_3, blockify_dhess_dtheta, blockify_third, blockify_hessian, safe_exp
 from scipy.integrate import quad
 import warnings
 from ..core.parameterization import Parameterized

GPy/testing/misc_tests.py

@@ -0,0 +1,18 @@
+import numpy as np
+import scipy as sp
+import GPy
+
+class MiscTests(np.testing.TestCase):
+    """
+    Testing some utilities of misc
+    """
+    def setUp(self):
+        self._lim_val = np.finfo(np.float64).max
+        self._lim_val_exp = np.log(self._lim_val)
+
+    def test_safe_exp_upper(self):
+        assert np.exp(self._lim_val_exp + 1) == np.inf
+        assert GPy.util.misc.safe_exp(self._lim_val_exp + 1) < np.inf
+
+    def test_safe_exp_lower(self):
+        assert GPy.util.misc.safe_exp(1e-10) < np.inf