ContinuousWavelet: add tests for dtype and remove unused **kwargs

doc/source/ref/wavelets.rst

@@ -260,13 +260,14 @@ from plain Python lists of filter coefficients and a *filter bank-like* object.
 ``ContinuousWavelet`` object
 ----------------------------
 
-.. class:: ContinuousWavelet(name)
+.. class:: ContinuousWavelet(name, dtype=np.float64)
 
   Describes properties of a continuous wavelet identified by the specified wavelet ``name``.
   In order to use a built-in wavelet the ``name`` parameter must be a valid
   wavelet name from the :func:`pywt.wavelist` list.
 
   :param name: Wavelet name
+  :param dtype: numpy.dtype to use for the wavelet. Can be numpy.float64 or numpy.float32.
 
   **Example:**
 

pywt/_extensions/_pywt.pyx

@@ -677,23 +677,24 @@ cdef public class Wavelet [type WaveletType, object WaveletObject]:
 
 cdef public class ContinuousWavelet [type ContinuousWaveletType, object ContinuousWaveletObject]:
     """
-    ContinuousWavelet(name) object describe properties of
+    ContinuousWavelet(name, dtype) object describe properties of
     a continuous wavelet identified by name.
 
     In order to use a built-in wavelet the parameter name must be
     a valid name from the wavelist() list.
 
     """
     #cdef readonly properties
-    def __cinit__(self, name=u"", dtype = None, **kwargs):
+    def __cinit__(self, name=u"", dtype=np.float64):
         cdef object family_code, family_number
 
         # builtin wavelet
         self.name = name.lower()
-        if (dtype is None):
-            self.dt = np.float64
-        else:
-            self.dt = dtype
+        self.dt = dtype
+        if np.dtype(self.dt) not in [np.float32, np.float64]:
+            raise ValueError(
+                "Only np.float32 and np.float64 dtype are supported for "
+                "ContinuousWavelet objects.")
         if len(self.name) >= 4 and self.name[:4] in ['cmor', 'shan', 'fbsp']:
             base_name = self.name[:4]
             if base_name == self.name:

pywt/tests/test_cwt_wavelets.py

@@ -115,6 +115,21 @@ def test_gaus():
         assert_allclose(X, x)
 
 
+@pytest.mark.parametrize('dtype', [np.float32, np.float64])
+def test_continuous_wavelet_dtype(dtype):
+    wavelet = pywt.ContinuousWavelet('cmor1.5-1.0', dtype)
+    int_psi, x = pywt.integrate_wavelet(wavelet)
+    assert int_psi.real.dtype == dtype
+    assert x.dtype == dtype
+
+
+def test_continuous_wavelet_invalid_dtype():
+    with pytest.raises(ValueError):
+        pywt.ContinuousWavelet('gaus5', np.complex64)
+    with pytest.raises(ValueError):
+        pywt.ContinuousWavelet('gaus5', np.int)
+
+
 def test_cgau():
     LB = -5
     UB = 5