Added simple_likelihood.py

imagine/likelihoods/simple_likelihood/__init__.py

+# -*- coding: utf-8 -*-
+

imagine/likelihoods/simple_likelihood/simple_likelihood.py

+# -*- coding: utf-8 -*-
+
+import numpy as np
+
+from imagine.likelihoods.likelihood import Likelihood
+
+
+class SimpleLikelihood(Likelihood):
+    def __init__(self, measured_data):
+        self.measured_data = measured_data
+
+    def __call__(self, observable):
+        shape = observable.shape
+        data = self.measured_data.val.get_full_data()
+        obs = observable.val.get_full_data()
+
+        quadratic_diff = ((data - obs).conjugate() * (data - obs)).sum()
+        quadratic_diff /= np.prod(shape)
+
+        return -quadratic_diff