more symbol additions for sympy conversion

src/finesse/symbols.pyx

@@ -43,6 +43,7 @@ PYFUNCTION_MAP = {
     "abs": operator.abs,
     "neg": operator.neg,
     "pos": operator.pos,
+    "pow": operator.pow,
     "conj": np.conj,
     "real": np.real,
     "imag": np.imag,
@@ -69,6 +70,7 @@ FUNCTIONS = {
     "abs": lambda x: Operation("abs", operator.abs, x),
     "neg": lambda x: Operation("neg", operator.neg, x),
     "pos": lambda x: Operation("pos", operator.pos, x),
+    "pow": lambda x: Operation("pow", operator.pow, x),
     "conj": lambda x: Operation("conj", np.conj, x),
     "real": lambda x: Operation("real", np.real, x),
     "imag": lambda x: Operation("imag", np.imag, x),
@@ -108,7 +110,15 @@ op_repr = {
 
 
 def finesse2sympy(expr, iter_num=0):
-    """"""
+    """
+    Notes
+    -----
+    It might be common for this this function to throw a NotImplementedError.
+    This function maps, by hand, various operator and numpy functions to sympy.
+    If you come across this error, you'll need to update the if-statement to
+    include the missing operations. Over time this should get fixed for most
+    use cases.
+    """
     import sympy
     from finesse.parameter import ParameterRef
     iter_num += 1
@@ -122,6 +132,10 @@ def finesse2sympy(expr, iter_num=0):
             op = sympy.Mul
         elif expr.op == operator.add:
             op = sympy.Add
+        elif expr.op == operator.truediv:
+            op = lambda a, b: sympy.Mul(a, sympy.Pow(b, -1))
+        elif expr.op == operator.pow:
+            op = sympy.Pow
         elif expr.op == operator.sub:
             op = lambda x,y: sympy.Add(x,-y)
         elif expr.op == np.conj:
@@ -132,13 +146,15 @@ def finesse2sympy(expr, iter_num=0):
             op = sympy.exp
         elif expr.op == np.sqrt:
             op = sympy.sqrt
+        elif expr.op == operator.abs:
+            op = sympy.Abs
         elif expr.op == operator.neg:
             op = lambda x: sympy.Mul(-1, x)
         else:
-            raise Exception(f"undefined Operation {expr.op} in {expr}")
+            raise NotImplementedError(f"undefined Operation {expr.op} in {expr}")
         return op(*sympy_args)
     else:
-        raise Exception(f'{expr} undefined')
+        raise NotImplementedError(f'{expr} undefined')
 
 def sympy2finesse(expr, symbol_dict={}, iter_num=0):
     import sympy