Fix in call to np.exp in the Numpy backend.

PiperOrigin-RevId: 456577290

Author: emilyfertig

tensorflow_probability/python/internal/backend/numpy/_utils.py

@@ -46,7 +46,7 @@ def _find_method_from_name(scope, name):
     child = scope[method[0]]
   else:
     child = getattr(scope, method[0])
-  if len(method) == 1 or (len(method) == 2 and method[0] == 'np'):
+  if len(method) == 1:
     return child
   return _find_method_from_name(child, method[1])
 

tensorflow_probability/python/internal/backend/numpy/numpy_math.py

@@ -363,8 +363,8 @@ def _alt_reduce_logsumexp(input_tensor, axis=None, keepdims=False):
   """Alternative to SP logsumexp."""
   m = _max_mask_non_finite(input_tensor, axis=axis, keepdims=True)
   y = input_tensor - m
-  y = np.exp(y, out=y)
-  if not keepdims:
+  y = np.exp(y)
+  if not keepdims and y.size > 0:
     m = np.squeeze(m, axis=_astuple(axis))
   return m + np.log(np.sum(y, axis=_astuple(axis), keepdims=keepdims))