diff --git a/feplot/entities.py b/feplot/entities.py
deleted file mode 100644
index 243da95..0000000
--- a/feplot/entities.py
+++ /dev/null
@@ -1,61 +0,0 @@
-
-"""
-    FEPlot
-    Created November 2022
-    Copyright (C) Mohamed ZAARAOUI
-
-    This program is free software; you can redistribute it and/or
-    modify it under the terms of the GNU General Public License
-    as published by the Free Software Foundation; either version 2
-    of the License, or (at your option) any later version.
-
-    This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with this program; if not, write to the Free Software
-    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-"""
-
-import numpy as np
-
-
-def arrow_3d(_ax, length=1, width=0.05, head=0.2, headwidth=2,
-             theta_x=0, theta_z=0, offset=(0, 0, 0), **kwargs):  # stackoverflow
-    """Add 3D arrow"""
-    _w = width
-    _h = head
-    _hw = headwidth
-    theta_x = np.deg2rad(theta_x)
-    theta_z = np.deg2rad(theta_z)
-
-    _a = np.array([[0, 0], [_w, 0], [_w, (1-_h)*length],
-                   [_hw*_w, (1-_h)*length], [0, length]])
-
-    _r, theta = np.meshgrid(_a[:, 0], np.linspace(0, 2*np.pi, 30))
-    _z = np.tile(_a[:, 1], _r.shape[0]).reshape(_r.shape)
-    _x = _r*np.sin(theta)
-    _y = _r*np.cos(theta)
-
-    rot_x = np.array([[1, 0, 0], [0, np.cos(theta_x), -np.sin(theta_x)],
-                      [0, np.sin(theta_x), np.cos(theta_x)]])
-    rot_z = np.array([[np.cos(theta_z), -np.sin(theta_z), 0],
-                      [np.sin(theta_z), np.cos(theta_z), 0], [0, 0, 1]])
-
-    b_1 = np.dot(rot_x, np.c_[_x.flatten(), _y.flatten(), _z.flatten()].T)
-    b_2 = np.dot(rot_z, b_1)
-    b_2 = b_2.T+np.array(offset)
-    _x = b_2[:, 0].reshape(_r.shape)
-    _y = b_2[:, 1].reshape(_r.shape)
-    _z = b_2[:, 2].reshape(_r.shape)
-    _ax.plot_surface(_x, _y, _z, **kwargs)
-    
-def sphere(_ax, origin=[0,0,0], radius=1, **kwargs):
-    """Plot a sphere defined by its radius"""
-    u, v = np.mgrid[0:2*np.pi:50j, 0:np.pi:50j]
-    x = origin[0] + radius*np.cos(u)*np.sin(v)
-    y = origin[1] + radius*np.sin(u)*np.sin(v)
-    z = origin[2] + radius*np.cos(v)
-    _ax.plot_surface(x, y, z, **kwargs)