global phase

src/pyqasm/printer.py

@@ -93,6 +93,9 @@ def _draw_mpl(module: Qasm3Module, idle_wires=True) -> plt.Figure:
     depths = dict()
     for k in line_nums.keys():
         depths[k] = -1
+
+    global_phase = sum([Qasm3ExprEvaluator.evaluate_expression(s.argument)[0] for s in statements if isinstance(s, ast.QuantumPhase)])
+    statements = [s for s in statements if not isinstance(s, ast.QuantumPhase)]
 
     moments = []
     for statement in statements:
@@ -109,12 +112,6 @@ def _draw_mpl(module: Qasm3Module, idle_wires=True) -> plt.Figure:
             depth = 1 + max(depths[qubit_key], depths[target_key])
             for k in [qubit_key, target_key]:
                 depths[k] = depth
-        elif isinstance(statement, ast.QuantumPhase):
-            qubits = [_identifier_to_key(q) for q in statement.qubits]
-            if len(qubits) > 0:
-                depth = 1 + max([depths[q] for q in qubits])
-                for q in qubits:
-                    depths[q] = depth
         elif isinstance(statement, ast.QuantumBarrier):
             qubits = [_identifier_to_key(q) for q in statement.qubits]
             depth = 1 + max([depths[q] for q in qubits])
@@ -175,6 +172,7 @@ def _draw_mpl(module: Qasm3Module, idle_wires=True) -> plt.Figure:
         ax = axs[sidx]
         x = 0
         if sidx == 0:
+            if global_phase != 0: _mpl_draw_global_phase(global_phase, ax, x)
             for k in module._qubit_registers.keys():
                 for i in range(module._qubit_registers[k]):
                     if (k, i) in line_nums:
@@ -213,11 +211,11 @@ def _identifier_to_key(identifier: ast.Identifier | ast.IndexedIdentifier) -> tu
 def _mpl_line_to_y(line_num: int) -> float:
     return line_num * (GATE_BOX_HEIGHT + LINE_SPACING)
 
+def _mpl_draw_global_phase(global_phase: float, ax: plt.Axes, x: float):
+    ax.text(x, -0.75, f"Global Phase: {global_phase:.3f}", ha="left", va="center")
 
 def _mpl_draw_qubit_label(qubit: tuple[str, int], line_num: int, ax: plt.Axes, x: float):
     ax.text(x, _mpl_line_to_y(line_num), f"{qubit[0]}[{qubit[1]}]", ha="right", va="center")
-
-
 def _mpl_draw_creg_label(creg: str, size: int, line_num: int, ax: plt.Axes, x: float):
     ax.text(x, _mpl_line_to_y(line_num), f"{creg[0]}", ha="right", va="center")
 
@@ -290,9 +288,6 @@ def _mpl_draw_statement(
         _mpl_draw_measurement(
             line_nums[qubit_key], line_nums[(target_key[0], -1)], target_key[1], ax, x
         )
-    elif isinstance(statement, ast.QuantumPhase):
-        # TODO: draw gphase
-        pass
     elif isinstance(statement, ast.QuantumBarrier):
         lines = [line_nums[_identifier_to_key(q)] for q in statement.qubits]
         _mpl_draw_barrier(lines, ax, x)