Draft: Add more WDF adaptors

Closes #257

b_asic/wdf_operations.py

@@ -85,8 +85,11 @@ class SeriesTwoportAdaptor(AbstractOperation):
     .. math::
         \begin{eqnarray}
         y_0 & = & x_0 - \text{value}\times\left(x_0 + x_1\right)\\
-        y_1 & = & x_1 - (2-\text{value})\times\left(x_0 + x_1\right)
+        y_1 & = & x_1 - (2-\text{value})\times\left(x_0 + x_1\right)\\
+            & = & -2x_0 - x_1  + \text{value}\times\left(x_0 + x_1\right)
         \end{eqnarray}
+
+    Port 1 is the dependent port.
     """
     is_linear = True
     is_swappable = True
@@ -120,7 +123,85 @@ class SeriesTwoportAdaptor(AbstractOperation):
     def evaluate(self, a, b):
         s = a + b
         val = self.value
-        return a - val * s, b - (2 - val) * s
+        t = val * a
+        y0 = a - t
+        y1 = -(s + y0)
+        return y0, y1
+
+    @property
+    def value(self) -> Num:
+        """Get the constant value of this operation."""
+        return self.param("value")
+
+    @value.setter
+    def value(self, value: Num) -> None:
+        """Set the constant value of this operation."""
+        if 0 <= value <= 2:
+            self.set_param("value", value)
+        else:
+            raise ValueError('value must be between 0 and 2 (inclusive)')
+
+    def swap_io(self) -> None:
+        # Swap inputs and outputs and, hence, which port is dependent
+        self._input_ports.reverse()
+        for i, p in enumerate(self._input_ports):
+            p._index = i
+        self._output_ports.reverse()
+        for i, p in enumerate(self._output_ports):
+            p._index = i
+        self.set_param("value", 2 - self.value)
+
+
+class ParallelTwoportAdaptor(AbstractOperation):
+    r"""
+    Wave digital filter parallel twoport-adaptor operation.
+
+    .. math::
+        \begin{eqnarray}
+        y_0 & = & - x_0 + \text{value}\times x_0 + (2 - \text{value}) \times x_1\\
+            & = & 2x_1 - x_0 + \text{value}\times \left(x_0 - x_1\right)
+        y_1 & = & - x_1 + \text{value}\times x_0 + (2 - \text{value}) \times x_1\\
+            & = & x_1 + \text{value}\times\left(x_0 - x_1\right)
+        \end{eqnarray}
+
+    Port 1 is the dependent port.
+    """
+    is_linear = True
+    is_swappable = True
+
+    def __init__(
+        self,
+        value: Num = 0,
+        src0: Optional[SignalSourceProvider] = None,
+        src1: Optional[SignalSourceProvider] = None,
+        name: Name = Name(""),
+        latency: Optional[int] = None,
+        latency_offsets: Optional[Dict[str, int]] = None,
+        execution_time: Optional[int] = None,
+    ):
+        """Construct a ParallelTwoportAdaptor operation."""
+        super().__init__(
+            input_count=2,
+            output_count=2,
+            name=Name(name),
+            input_sources=[src0, src1],
+            latency=latency,
+            latency_offsets=latency_offsets,
+            execution_time=execution_time,
+        )
+        self.value = value
+
+    @classmethod
+    def type_name(cls) -> TypeName:
+        return TypeName("par2p")
+
+    def evaluate(self, a, b):
+        s = b - a
+        val = self.value
+        t = val * s
+        y1 = b - t
+        y0 = y1 + s
+        return y0, y1
 
     @property
     def value(self) -> Num:
@@ -196,7 +277,8 @@ class SeriesThreeportAdaptor(AbstractOperation):
         val0, val1 = self.value
         y0 = a - val0 * s
         y1 = b - val1 * s
-        return y0, y1, -(y0 + y1 + s)
+        y2 = -(y0 + y1 + s)
+        return y0, y1, y2
 
     @property
     def value(self) -> Tuple[Num, Num]:
@@ -220,9 +302,12 @@ class ReflectionFreeSeriesThreeportAdaptor(AbstractOperation):
 
     .. math::
         \begin{eqnarray}
-        y_0 & = & x_0 + \text{value}\times\left(x_0 - x_1 + x_2\right)\\
+        y_0 & = & x_0 - \text{value}\times\left(x_0 + x_1 + x_2\right)\\
         y_1 & = & -x_0 - x_2\\
-        y_2 & = & -x_0 - x_2 - \text{value}\times\left(x_0 - x_1 + x_2\right)
+        y_2 & = & x_2 - \left(1 - \text{value}\right)\times\left(x_0
+                + x_1 + x_2\right) \\
+            & = & -x_0 - x_1 + \text{value}\times\left(x_0
+                    + x_1 + x_2\right)
         \end{eqnarray}
 
     Port 1 is the reflection-free port and port 2 is the dependent port.
@@ -258,8 +343,9 @@ class ReflectionFreeSeriesThreeportAdaptor(AbstractOperation):
         return TypeName("rfs3p")
 
     def evaluate(self, a, b, c):
-        y1 = -(a + c)
-        y0 = a - self.value * (b + y1)
+        s = a + c
+        y1 = -s
+        y0 = a - self.value * (b + s)
         y2 = -(y0 + b)
         return y0, y1, y2