Merge pull request #8788 from eric-wieser/poly1d-fixes-fixes

BUG: Fix scipy incompatibility with cleanup to poly1d

1 files changed, 11 insertions, 1 deletions

diff --git a/numpy/lib/polynomial.py b/numpy/lib/polynomial.py
index 50e6d8db2..e18bbc8bc 100644
--- a/numpy/lib/polynomial.py
+++ b/numpy/lib/polynomial.py
@@ -1041,7 +1041,7 @@ class poly1d(object):
     @property
     def coeffs(self):
         """ The polynomial coefficients """
-        return self._coeffs
+        return self._coeffs.copy()
 
     @property
     def variable(self):
@@ -1059,6 +1059,16 @@ class poly1d(object):
         """ The roots of the polynomial, where self(x) == 0 """
         return roots(self._coeffs)
 
+    # our internal _coeffs property need to be backed by __dict__['coeffs'] for
+    # scipy to work correctly. Note that as a result, the getter for .coeffs
+    # does not run unless accessed through one of its aliases.
+    @property
+    def _coeffs(self):
+        return self.__dict__['coeffs']
+    @_coeffs.setter
+    def _coeffs(self, coeffs):
+        self.__dict__['coeffs'] = coeffs
+
     # alias attributes
     r = roots
     c = coef = coefficients = coeffs