Changed nested samplers to allow any logpdf as a loglikelihood.

Author: MichaelClerx

pints/_nested/__init__.py

@@ -27,7 +27,8 @@ class NestedSampler(object):
     def __init__(self, log_likelihood, log_prior):
 
         # Store log_likelihood and log_prior
-        if not isinstance(log_likelihood, pints.LogLikelihood):
+        #if not isinstance(log_likelihood, pints.LogLikelihood):
+        if not isinstance(log_likelihood, pints.LogPDF):
             raise ValueError(
                 'Given log_likelihood must extend pints.LogLikelihood')
         self._log_likelihood = log_likelihood

pints/tests/test_nested_sampling.py

@@ -77,7 +77,7 @@ def test_construction_errors(self):
         # First arg must be a log likelihood
         self.assertRaisesRegex(
             ValueError, 'must extend pints.LogLikelihood',
-            pints.NestedRejectionSampler, self.log_prior, self.log_prior)
+            pints.NestedRejectionSampler, 'hello', self.log_prior)
 
         # First arg must be a log prior
         self.assertRaisesRegex(
@@ -234,7 +234,7 @@ def test_construction_errors(self):
         # First arg must be a log likelihood
         self.assertRaisesRegex(
             ValueError, 'must extend pints.LogLikelihood',
-            pints.NestedEllipsoidSampler, self.log_prior, self.log_prior)
+            pints.NestedEllipsoidSampler, 'hiya', self.log_prior)
 
         # First arg must be a log prior
         self.assertRaisesRegex(