diff --git a/wafo/containers.py b/wafo/containers.py
index fe3d65c..661b165 100644
--- a/wafo/containers.py
+++ b/wafo/containers.py
@@ -198,7 +198,7 @@ class PlotData(object):
         if return_ci:
             res_ci = [child.integrate(a, b, method=method)
                       for child in self.children]
-            return np.hstack((res, res_ci))
+            return np.hstack((res, np.ravel(res_ci)))
         return res
 
     def plot(self, *args, **kwds):
@@ -601,8 +601,8 @@ def test_plotdata():
     x = np.linspace(0, np.pi, 9)
     xi = np.linspace(0, np.pi, 4*9)
 
-    d = PlotData(np.sin(x)/2, x, dataCI=[], xlab='x', ylab='sin', title='sinus',
-                 plot_args=['r.'])
+    d = PlotData(np.sin(x)/2, x, dataCI=[], xlab='x', ylab='sin',
+                 title='sinus', plot_args=['r.'])
     di = PlotData(d.eval_points(xi, method='cubic'), xi)
     unused_hi = di.plot()
     unused_h = d.plot()
@@ -620,5 +620,5 @@ def test_docstrings():
 
 
 if __name__ == '__main__':
-    # test_docstrings()
-    test_plotdata()
+    test_docstrings()
+    # test_plotdata()
diff --git a/wafo/interpolate.py b/wafo/interpolate.py
index b456593..b3526e0 100644
--- a/wafo/interpolate.py
+++ b/wafo/interpolate.py
@@ -222,7 +222,7 @@ def sgolay2d(z, window_size, order, derivative=None):
     exps = [(k - n, n) for k in range(order + 1) for n in range(k + 1)]
 
     # coordinates of points
-    ind = np.arange(-half_size, half_size + 1, dtype=np.float64)
+    ind = np.arange(-half_size, half_size + 1, dtype=np.float)
     dx = np.repeat(ind, window_size)
     dy = np.tile(ind, [window_size, 1]).reshape(window_size ** 2,)
 
diff --git a/wafo/sg_filter.py b/wafo/sg_filter.py
index 22a6533..999c4cd 100644
--- a/wafo/sg_filter.py
+++ b/wafo/sg_filter.py
@@ -132,7 +132,7 @@ class SavitzkyGolay(object):
 
     def smooth_last(self, signal, k=0):
         coeff = self._coeff
-        n = np.size((coeff - 1) // 2
+        n = (np.size(coeff) - 1) // 2
         y = np.squeeze(signal)
         if n == 0:
             return y