Create dynamical_system.py

dynamical_system.py

@@ -0,0 +1,9 @@
+def invasion_fitness(z, zm, pars):
+    n_res = z / pars
+    return zm - pars * n_res
+
+
+def invasion_fitness2(z, zm, pars):
+    alpha, beta = pars
+    n_res = (z - z**beta) / alpha
+    return zm - zm**beta - alpha * n_res