add sympy support; which can transfer your network into sympy expression;

add visualize in genome;
add related tests.

tensorneat/utils/activation/act_sympy.py

@@ -0,0 +1,191 @@
+from typing import Union
+import sympy as sp
+import numpy as np
+
+
+class SympyClip(sp.Function):
+    @classmethod
+    def eval(cls, val, min_val, max_val):
+        if val.is_Number and min_val.is_Number and max_val.is_Number:
+            return sp.Piecewise(
+                (min_val, val < min_val), (max_val, val > max_val), (val, True)
+            )
+        return None
+
+    @staticmethod
+    def numerical_eval(val, min_val, max_val):
+        return np.clip(val, min_val, max_val)
+
+    def _sympystr(self, printer):
+        return f"clip({self.args[0]}, {self.args[1]}, {self.args[2]})"
+
+    def _latex(self, printer):
+        return rf"\mathrm{{clip}}\left({sp.latex(self.args[0])}, {self.args[1]}, {self.args[2]}\right)"
+
+
+class SympySigmoid(sp.Function):
+    @classmethod
+    def eval(cls, z):
+        if z.is_Number:
+            z = SympyClip(5 * z, -10, 10)
+            return 1 / (1 + sp.exp(-z))
+        return None
+
+    @staticmethod
+    def numerical_eval(z):
+        z = np.clip(5 * z, -10, 10)
+        return 1 / (1 + np.exp(-z))
+
+    def _sympystr(self, printer):
+        return f"sigmoid({self.args[0]})"
+
+    def _latex(self, printer):
+        return rf"\mathrm{{sigmoid}}\left({sp.latex(self.args[0])}\right)"
+
+
+class SympyTanh(sp.Function):
+    @classmethod
+    def eval(cls, z):
+        return sp.tanh(0.6 * z)
+
+    @staticmethod
+    def numerical_eval(z):
+        return np.tanh(0.6 * z)
+
+
+class SympySin(sp.Function):
+    @classmethod
+    def eval(cls, z):
+        return sp.sin(z)
+
+    @staticmethod
+    def numerical_eval(z):
+        return np.sin(z)
+
+
+class SympyRelu(sp.Function):
+    @classmethod
+    def eval(cls, z):
+        if z.is_Number:
+            return sp.Piecewise((z, z > 0), (0, True))
+        return None
+
+    @staticmethod
+    def numerical_eval(z):
+        return np.maximum(z, 0)
+
+    def _sympystr(self, printer):
+        return f"relu({self.args[0]})"
+
+    def _latex(self, printer):
+        return rf"\mathrm{{relu}}\left({sp.latex(self.args[0])}\right)"
+
+
+class SympyLelu(sp.Function):
+    @classmethod
+    def eval(cls, z):
+        if z.is_Number:
+            leaky = 0.005
+            return sp.Piecewise((z, z > 0), (leaky * z, True))
+        return None
+
+    @staticmethod
+    def numerical_eval(z):
+        leaky = 0.005
+        return np.maximum(z, leaky * z)
+
+    def _sympystr(self, printer):
+        return f"lelu({self.args[0]})"
+
+    def _latex(self, printer):
+        return rf"\mathrm{{lelu}}\left({sp.latex(self.args[0])}\right)"
+
+
+class SympyIdentity(sp.Function):
+    @classmethod
+    def eval(cls, z):
+        return z
+
+    @staticmethod
+    def numerical_eval(z):
+        return z
+
+
+class SympyClamped(sp.Function):
+    @classmethod
+    def eval(cls, z):
+        return SympyClip(z, -1, 1)
+
+    @staticmethod
+    def numerical_eval(z):
+        return np.clip(z, -1, 1)
+
+
+class SympyInv(sp.Function):
+    @classmethod
+    def eval(cls, z):
+        if z.is_Number:
+            z = sp.Piecewise((sp.Max(z, 1e-7), z > 0), (sp.Min(z, -1e-7), True))
+            return 1 / z
+        return None
+
+    @staticmethod
+    def numerical_eval(z):
+        z = np.maximum(z, 1e-7)
+        return 1 / z
+
+    def _sympystr(self, printer):
+        return f"1 / {self.args[0]}"
+
+    def _latex(self, printer):
+        return rf"\frac{{1}}{{{sp.latex(self.args[0])}}}"
+
+
+class SympyLog(sp.Function):
+    @classmethod
+    def eval(cls, z):
+        if z.is_Number:
+            z = sp.Max(z, 1e-7)
+            return sp.log(z)
+        return None
+
+    @staticmethod
+    def numerical_eval(z):
+        z = np.maximum(z, 1e-7)
+        return np.log(z)
+
+    def _sympystr(self, printer):
+        return f"log({self.args[0]})"
+
+    def _latex(self, printer):
+        return rf"\mathrm{{log}}\left({sp.latex(self.args[0])}\right)"
+
+
+class SympyExp(sp.Function):
+    @classmethod
+    def eval(cls, z):
+        if z.is_Number:
+            z = SympyClip(z, -10, 10)
+            return sp.exp(z)
+        return None
+
+    @staticmethod
+    def numerical_eval(z):
+        z = np.clip(z, -10, 10)
+        return np.exp(z)
+
+    def _sympystr(self, printer):
+        return f"exp({self.args[0]})"
+
+    def _latex(self, printer):
+        return rf"\mathrm{{exp}}\left({sp.latex(self.args[0])}\right)"
+
+
+class SympyAbs(sp.Function):
+    @classmethod
+    def eval(cls, z):
+        return sp.Abs(z)
+
+    @staticmethod
+    def numerical_eval(z):
+        return np.abs(z)