BUG: copy certain interpolate arguments to ensure we can write to them;

closes #7295.

Author: dsm054

pandas/core/common.py

@@ -1538,6 +1538,14 @@ def _interpolate_scipy_wrapper(x, y, new_x, method, fill_value=None,
         terp = interpolate.UnivariateSpline(x, y, k=order)
         new_y = terp(new_x)
     else:
+        # GH 7295: need to be able to write for some reason
+        # in some circumstances: check all three
+        if not x.flags.writeable:
+            x = x.copy()
+        if not y.flags.writeable:
+            y = y.copy()
+        if not new_x.flags.writeable:
+            new_x = new_x.copy()
         method = alt_methods[method]
         new_y = method(x, y, new_x)
     return new_y