1# ##### BEGIN GPL LICENSE BLOCK #####
2#
3#  This program is free software; you can redistribute it and/or
4#  modify it under the terms of the GNU General Public License
5#  as published by the Free Software Foundation; either version 2
6#  of the License, or (at your option) any later version.
7#
8#  This program is distributed in the hope that it will be useful,
9#  but WITHOUT ANY WARRANTY; without even the implied warranty of
10#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11#  GNU General Public License for more details.
12#
13#  You should have received a copy of the GNU General Public License
14#  along with this program; if not, write to the Free Software Foundation,
15#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
16#
17# ##### END GPL LICENSE BLOCK #####
18
19import numpy as np
20try:
21    from numba import jit
22
23    @jit
24    def numba_reaction_diffusion(n_verts, n_edges, edge_verts, a, b, diff_a, diff_b, f, k, dt, time_steps):
25        arr = np.arange(n_edges)*2
26        id0 = edge_verts[arr]     # first vertex indices for each edge
27        id1 = edge_verts[arr+1]   # second vertex indices for each edge
28        for i in range(time_steps):
29            lap_a = np.zeros(n_verts)
30            lap_b = np.zeros(n_verts)
31            lap_a0 =  a[id1] -  a[id0]   # laplacian increment for first vertex of each edge
32            lap_b0 =  b[id1] -  b[id0]   # laplacian increment for first vertex of each edge
33
34            for i, j, la0, lb0 in zip(id0,id1,lap_a0,lap_b0):
35                lap_a[i] += la0
36                lap_b[i] += lb0
37                lap_a[j] -= la0
38                lap_b[j] -= lb0
39            ab2 = a*b**2
40            #a += eval("(diff_a*lap_a - ab2 + f*(1-a))*dt")
41            #b += eval("(diff_b*lap_b + ab2 - (k+f)*b)*dt")
42            a += (diff_a*lap_a - ab2 + f*(1-a))*dt
43            b += (diff_b*lap_b + ab2 - (k+f)*b)*dt
44        return a, b
45except:
46    pass
47