From ea5fe5ff9cf941ea13fdf4f5d7578fea64d6a335 Mon Sep 17 00:00:00 2001
From: Tim Sheerman-Chase <t.sheerman-chase@surrey.ac.uk>
Date: Sat, 1 Sep 2012 12:38:25 +0100
Subject: [PATCH] Setting _matrix to None, because the transform is not of this
 form

---
 skimage/transform/_geometric.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/skimage/transform/_geometric.py b/skimage/transform/_geometric.py
index 9869fd87..030197da 100644
--- a/skimage/transform/_geometric.py
+++ b/skimage/transform/_geometric.py
@@ -597,6 +597,7 @@ class PiecewiseAffineTransform(ProjectiveTransform):
     def __init__(self):
         self.tess = None
         self.triAffines = []
+        self._matrix = None
 
     def estimate(self, src, dst):
         """Set the control points with which to perform the piecewise affine mapping.