diff --git a/blobmodel/blob_shape.py b/blobmodel/blob_shape.py
index 4bb2cf1..fa1f1e8 100644
--- a/blobmodel/blob_shape.py
+++ b/blobmodel/blob_shape.py
@@ -20,6 +20,137 @@ def get_blob_shape_perp(self, theta: np.ndarray, **kwargs) -> np.ndarray:
         raise NotImplementedError
 
 
+def _get_exponential_shape(theta: np.ndarray, **kwargs) -> np.ndarray:
+    """Compute the exponential pulse shape.
+
+    Parameters
+    ----------
+    theta : np.ndarray
+        Array of theta values.
+    kwargs
+        Additional keyword arguments.
+
+    Returns
+    -------
+    np.ndarray
+        Array representing the exponential pulse shape.
+    """
+    return np.exp(theta) * np.heaviside(-1.0 * theta, 1)
+
+
+def _get_lorentz_shape(theta: np.ndarray, **kwargs) -> np.ndarray:
+    """Compute the Lorentzian pulse shape.
+
+    Parameters
+    ----------
+    theta : np.ndarray
+        Array of theta values.
+    kwargs
+        Additional keyword arguments.
+
+    Returns
+    -------
+    np.ndarray
+        Array representing the Lorentzian pulse shape.
+    """
+    return 1 / (np.pi * (1 + theta**2))
+
+
+def _get_double_exponential_shape(theta: np.ndarray, **kwargs) -> np.ndarray:
+    """Compute the double-exponential pulse shape.
+
+    Parameters
+    ----------
+    theta : np.ndarray
+        Array of theta values.
+    kwargs
+        Additional keyword arguments.
+        lam : float
+            Asymmetry parameter controlling the shape.
+
+    Returns
+    -------
+    np.ndarray
+        Array representing the double-exponential pulse shape.
+    """
+    lam = kwargs["lam"]
+    assert (lam > 0.0) & (lam < 1.0)
+    kern = np.zeros(shape=np.shape(theta))
+    kern[theta < 0] = np.exp(theta[theta < 0] / lam)
+    kern[theta >= 0] = np.exp(-theta[theta >= 0] / (1 - lam))
+    return kern
+
+
+def _get_gaussian_shape(theta: np.ndarray, **kwargs) -> np.ndarray:
+    """Compute the Gaussian pulse shape.
+
+    Parameters
+    ----------
+    theta : np.ndarray
+        Array of theta values.
+    kwargs
+        Additional keyword arguments.
+
+    Returns
+    -------
+    np.ndarray
+        Array representing the Gaussian pulse shape.
+    """
+    return 1 / np.sqrt(2 * np.pi) * np.exp(-(theta**2) / 2)
+
+
+def _get_rectangle_shape(theta: np.ndarray, **kwargs) -> np.ndarray:
+    """Compute the hard ellipse pulse shape.
+    Parameters
+    ----------
+    theta : np.ndarray
+        Array of theta values.
+    kwargs
+        Additional keyword arguments.
+    Returns
+    -------
+    np.ndarray
+        Array representing the rectangle pulse shape.
+    """
+    return np.abs(theta) < 0.5
+
+
+def _get_secant_shape(theta: np.ndarray, **kwargs) -> np.ndarray:
+    """Compute the secant pulse shape.
+
+    Parameters
+    ----------
+    theta : np.ndarray
+        Array of theta values.
+    kwargs
+        Additional keyword arguments.
+
+    Returns
+    -------
+    np.ndarray
+        Array representing the secant pulse shape.
+    """
+    return 2 / np.pi / (np.exp(theta) + np.exp(-theta))
+
+
+def _get_dipole_shape(theta: np.ndarray, **kwargs) -> np.ndarray:
+    """Compute the diople pulse shape as a derivative of a gaussian pulse shape.
+
+    Parameters
+    ----------
+    theta : np.ndarray
+        Array of theta values.
+    kwargs
+        Additional keyword arguments.
+
+    Returns
+    -------
+    np.ndarray
+        Array representing the dipole pulse shape.
+    """
+    return -2 * theta / np.sqrt(2 * np.pi) * np.exp(-(theta**2) / 2)
+
+
 class BlobShapeImpl(AbstractBlobShape):
     """Implementation of the AbstractPulseShape class."""
 
@@ -77,132 +208,6 @@ def get_blob_shape_perp(self, theta: np.ndarray, **kwargs) -> np.ndarray:
         """
         raise NotImplementedError
 
-    def _get_exponential_shape(theta: np.ndarray, **kwargs) -> np.ndarray:
-        """Compute the exponential pulse shape.
-
-        Parameters
-        ----------
-        theta : np.ndarray
-            Array of theta values.
-        kwargs
-            Additional keyword arguments.
-
-        Returns
-        -------
-        np.ndarray
-            Array representing the exponential pulse shape.
-        """
-        return np.exp(theta) * np.heaviside(-1.0 * theta, 1)
-
-    def _get_lorentz_shape(theta: np.ndarray, **kwargs) -> np.ndarray:
-        """Compute the Lorentzian pulse shape.
-
-        Parameters
-        ----------
-        theta : np.ndarray
-            Array of theta values.
-        kwargs
-            Additional keyword arguments.
-
-        Returns
-        -------
-        np.ndarray
-            Array representing the Lorentzian pulse shape.
-        """
-        return 1 / (np.pi * (1 + theta**2))
-
-    def _get_double_exponential_shape(theta: np.ndarray, **kwargs) -> np.ndarray:
-        """Compute the double-exponential pulse shape.
-
-        Parameters
-        ----------
-        theta : np.ndarray
-            Array of theta values.
-        kwargs
-            Additional keyword arguments.
-            lam : float
-                Asymmetry parameter controlling the shape.
-
-        Returns
-        -------
-        np.ndarray
-            Array representing the double-exponential pulse shape.
-        """
-        lam = kwargs["lam"]
-        assert (lam > 0.0) & (lam < 1.0)
-        kern = np.zeros(shape=np.shape(theta))
-        kern[theta < 0] = np.exp(theta[theta < 0] / lam)
-        kern[theta >= 0] = np.exp(-theta[theta >= 0] / (1 - lam))
-        return kern
-
-    def _get_gaussian_shape(theta: np.ndarray, **kwargs) -> np.ndarray:
-        """Compute the Gaussian pulse shape.
-
-        Parameters
-        ----------
-        theta : np.ndarray
-            Array of theta values.
-        kwargs
-            Additional keyword arguments.
-
-        Returns
-        -------
-        np.ndarray
-            Array representing the Gaussian pulse shape.
-        """
-        return 1 / np.sqrt(2 * np.pi) * np.exp(-(theta**2) / 2)
-
-    def _get_secant_shape(theta: np.ndarray, **kwargs) -> np.ndarray:
-        """Compute the secant pulse shape.
-
-        Parameters
-        ----------
-        theta : np.ndarray
-            Array of theta values.
-        kwargs
-            Additional keyword arguments.
-
-        Returns
-        -------
-        np.ndarray
-            Array representing the secant pulse shape.
-        """
-        return 2 / np.pi / (np.exp(theta) + np.exp(-theta))
-
-    def _get_dipole_shape(theta: np.ndarray, **kwargs) -> np.ndarray:
-        """Compute the diople pulse shape as a derivative of a gaussian pulse shape.
-
-        Parameters
-        ----------
-        theta : np.ndarray
-            Array of theta values.
-        kwargs
-            Additional keyword arguments.
-
-        Returns
-        -------
-        np.ndarray
-            Array representing the dipole pulse shape.
-        """
-        return -2 * theta / np.sqrt(2 * np.pi) * np.exp(-(theta**2) / 2)
-
-    def _get_rectangle_shape(theta: np.ndarray, **kwargs) -> np.ndarray:
-        """Compute the hard ellipse pulse shape.
-
-        Parameters
-        ----------
-        theta : np.ndarray
-            Array of theta values.
-        kwargs
-            Additional keyword arguments.
-
-        Returns
-        -------
-        np.ndarray
-            Array representing the rectangle pulse shape.
-        """
-        return np.abs(theta) < 0.5
-
     __GENERATORS = {
         "exp": _get_exponential_shape,
         "gauss": _get_gaussian_shape,
diff --git a/examples/blob_tilting.py b/examples/blob_tilting.py
index 32773e3..e696e25 100644
--- a/examples/blob_tilting.py
+++ b/examples/blob_tilting.py
@@ -2,8 +2,8 @@
 import numpy as np
 
 # velocities
-vx = 0
-vy = 1
+vx = 1
+vy = 0
 
 # sizes
 wx = 3
diff --git a/tests/test_pulse_shape.py b/tests/test_pulse_shape.py
index 688bdcc..1d077ab 100644
--- a/tests/test_pulse_shape.py
+++ b/tests/test_pulse_shape.py
@@ -1,5 +1,5 @@
 import pytest
-from blobmodel import BlobShapeImpl, AbstractBlobShape, BlobShapeImpl
+from blobmodel import AbstractBlobShape, BlobShapeImpl
 import numpy as np
 
 
@@ -47,24 +47,33 @@ def test__get_double_exponential_shape():
     theta = np.array([-1, 0, 1])
     lam = 0.5
     expected_result = np.array([0.13533528, 1.0, 0.13533528])
-    assert np.allclose(
-        BlobShapeImpl._get_double_exponential_shape(theta, lam=lam), expected_result
-    )
+    ps = BlobShapeImpl("2-exp", "2-exp")
+    values = ps.get_blob_shape_perp(theta, lam=lam)
+    assert np.max(np.abs(values - expected_result)) < 1e-5, "Wrong shape"
 
 
 def test__get_secant_shape():
     theta = np.array([1, 2, 3])
     expected_result = np.array([0.20628208, 0.08460748, 0.03161706])
-    assert np.allclose(BlobShapeImpl._get_secant_shape(theta), expected_result)
+
+    ps = BlobShapeImpl("secant", "secant")
+    values = ps.get_blob_shape_perp(theta)
+    assert np.max(np.abs(values - expected_result)) < 1e-5, "Wrong shape"
 
 
 def test__get_lorentz_shape():
     theta = np.array([1, 2, 3])
     expected_result = np.array([0.15915494, 0.06366198, 0.03183099])
-    assert np.allclose(BlobShapeImpl._get_lorentz_shape(theta), expected_result)
+
+    ps = BlobShapeImpl("lorentz", "lorentz")
+    values = ps.get_blob_shape_perp(theta)
+    assert np.max(np.abs(values - expected_result)) < 1e-5, "Wrong shape"
 
 
 def test__get_dipole_shape():
     theta = np.array([1, 2, 3])
     expected_result = np.array([-0.48394145, -0.21596387, -0.02659109])
-    assert np.allclose(BlobShapeImpl._get_dipole_shape(theta), expected_result)
+
+    ps = BlobShapeImpl("dipole", "dipole")
+    values = ps.get_blob_shape_perp(theta)
+    assert np.max(np.abs(values - expected_result)) < 1e-5, "Wrong shape"