From c22d63b93f6b4bce55bc7060f6b044073f6c6231 Mon Sep 17 00:00:00 2001
From: "Per.Andreas.Brodtkorb"
 <Per.Andreas.Brodtkorb@96a810ac-173e-11df-b9d6-e102a254d9bb>
Date: Mon, 29 Nov 2010 16:04:48 +0000
Subject: [PATCH] Fixed a bug in kde.eval_grid_fast + updated tests

---
 pywafo/src/wafo/kdetools.py           | 22 ++++++++++++----------
 pywafo/src/wafo/test/test_kdetools.py | 25 +++++++++++++++++++++++++
 2 files changed, 37 insertions(+), 10 deletions(-)

diff --git a/pywafo/src/wafo/kdetools.py b/pywafo/src/wafo/kdetools.py
index ea86ad6..a289a81 100644
--- a/pywafo/src/wafo/kdetools.py
+++ b/pywafo/src/wafo/kdetools.py
@@ -119,8 +119,8 @@ class TKDE(object):
             0.20717946,  0.15907684,  0.1201074 ,  0.08941027,  0.06574882])
             
     >>> kde.eval_grid_fast(x)
-    array([ 0.        ,  1.16200356,  0.99256178,  0.81930973,  0.65479862,
-            0.51021576,  0.3896221 ,  0.29266142,  0.        ,  0.        ])
+    array([ 0.        ,  0.4614821 ,  0.39554839,  0.32764086,  0.26275681,
+            0.20543731,  0.15741056,  0.11863464,  0.        ,  0.        ])
             
     import pylab as plb          
     h1 = plb.plot(x, f) #  1D probability density plot
@@ -377,8 +377,8 @@ class KDE(object):
     
     >>> f = kde0.eval_grid_fast()
     >>> np.interp(x, kde0.args[0], f)
-    array([ 0.54344   ,  1.04793706,  1.38047458,  1.28324876,  0.943131  ,
-            0.63570524,  0.39404219,  0.19450807,  0.08505344,  0.08505344])
+    array([ 0.21165996,  0.41218257,  0.54961961,  0.51713209,  0.38292245,
+            0.25864661,  0.16113184,  0.08055992,  0.03576856,  0.03576856])
             
     import pylab as plb          
     h1 = plb.plot(x, f) #  1D probability density plot
@@ -473,6 +473,7 @@ class KDE(object):
         self.args = args
         return self._eval_grid_fast(*args)
     def _eval_grid_fast(self, *args):
+        # TODO: This does not work correctly yet! Check it.
         X = np.vstack(args)
         d, inc = X.shape
         dx = X[:,1]-X[:,0]
@@ -480,9 +481,9 @@ class KDE(object):
         Xn = []
         nfft0 = 2*inc
         nfft = (nfft0,)*d
-        x0 = np.linspace(-inc, inc, nfft0)
+        x0 = np.linspace(-inc, inc, nfft0+1)
         for i in range(d):
-            Xn.append(x0*dx[i])
+            Xn.append(x0[:-1]*dx[i])
         
         Xnc = meshgrid(*Xn) if d>1 else Xn
         
@@ -493,7 +494,7 @@ class KDE(object):
         Xn = np.dot(self.inv_hs, np.vstack(Xnc))
         
         # Obtain the kernel weights.        
-        kw = self.kernel(Xn)/self._norm_factor
+        kw = self.kernel(Xn)/(self._norm_factor * self.kernel.norm_factor(d, self.n))
         kw.shape = shape0
         kw = np.fft.ifftshift(kw)
         fftn = np.fft.fftn
@@ -1302,11 +1303,12 @@ def bitget(int_type, offset):
     
     Example
     -------
-    >>> bitget(5, np.r_[0:4])
+    >>> bitget(5, np.r_[0:4])   
     array([1, 0, 1, 0])
     '''
-    mask = (1 << offset)
-    return (int_type & mask) != 0
+    
+    return np.bitwise_and(int_type, 1 << offset) >> offset
+    
 
 def gridcount(data, X):
     '''
diff --git a/pywafo/src/wafo/test/test_kdetools.py b/pywafo/src/wafo/test/test_kdetools.py
index c092c94..a850a45 100644
--- a/pywafo/src/wafo/test/test_kdetools.py
+++ b/pywafo/src/wafo/test/test_kdetools.py
@@ -9,6 +9,31 @@ from numpy import array
 import wafo.kdetools as wk
 import pylab as plb
 
+def test0_KDE1D():
+    '''
+    >>> data = array([ 0.75355792,  0.72779194,  0.94149169,  0.07841119,  2.32291887,
+    ...        1.10419995,  0.77055114,  0.60288273,  1.36883635,  1.74754326,
+    ...        1.09547561,  1.01671133,  0.73211143,  0.61891719,  0.75903487,
+    ...        1.8919469 ,  0.72433808,  1.92973094,  0.44749838,  1.36508452])
+
+    >>> x = np.linspace(0, max(data.ravel()) + 1, 10) 
+    >>> import wafo.kdetools as wk 
+    >>> kde = wk.KDE(data, hs=0.5, alpha=0.5)
+   
+    >>> kde0 = wk.KDE(data, hs=0.5, alpha=0.0, inc=16)
+    
+    >>> kde0.eval_grid(x)
+    array([ 0.2039735 ,  0.40252503,  0.54595078,  0.52219649,  0.3906213 ,
+            0.26381501,  0.16407362,  0.08270612,  0.02991145,  0.00720821])       
+    
+    >>> f = kde0.eval_grid_fast(); f
+    array([ 0.07264948,  0.14135253,  0.24141397,  0.36045498,  0.46962192,
+            0.53604004,  0.5427015 ,  0.49767387,  0.42419428,  0.34349993,
+            0.26650289,  0.19666903,  0.13569857,  0.0857818 ,  0.04868357,
+            0.02432961])
+    >>> np.trapz(f,kde0.args)
+    array([ 0.97384215])
+    '''
 def test1_TKDE1D():
     '''
     N = 20