QasmModule Circuit Drawer

pyproject.toml

@@ -32,7 +32,7 @@ classifiers = [
     "Operating System :: Unix",
     "Operating System :: MacOS",
 ]
-dependencies = ["numpy", "openqasm3[parser]>=1.0.0,<2.0.0"]
+dependencies = ["numpy", "matplotlib", "openqasm3[parser]>=1.0.0,<2.0.0"]
 
 [project.urls]
 "Source Code" = "https://github.com/qBraid/pyqasm"

src/pyqasm/maps.py

@@ -1236,6 +1236,21 @@ def map_qasm_inv_op_to_callable(op_name: str):
     raise ValidationError(f"Unsupported / undeclared QASM operation: {op_name}")
 
 
+REV_CTRL_GATE_MAP = {
+    "cx": "x",
+    "cy": "y",
+    "cz": "z",
+    "crx": "rx",
+    "cry": "ry",
+    "crz": "rz",
+    "cp": "p",
+    "ch": "h",
+    "cu": "u",
+    "cswap": "swap",
+    "ccx": "cx",
+}
+
+
 # pylint: disable=inconsistent-return-statements
 def qasm_variable_type_cast(openqasm_type, var_name, base_size, rhs_value):
     """Cast the variable type to the type to match, if possible.

src/pyqasm/modules/base.py

@@ -551,3 +551,7 @@ def accept(self, visitor):
         Args:
             visitor (QasmVisitor): The visitor to accept
         """
+
+    @abstractmethod
+    def draw(self):
+        """Draw the module"""

src/pyqasm/modules/qasm2.py

@@ -23,6 +23,7 @@
 from pyqasm.exceptions import ValidationError
 from pyqasm.modules.base import QasmModule
 from pyqasm.modules.qasm3 import Qasm3Module
+from pyqasm.printer import draw
 
 
 class Qasm2Module(QasmModule):
@@ -105,3 +106,7 @@ def accept(self, visitor):
         final_stmt_list = visitor.finalize(unrolled_stmt_list)
 
         self.unrolled_ast.statements = final_stmt_list
+
+    def draw(self):
+        """Draw the module"""
+        return draw(self.to_qasm3())

src/pyqasm/modules/qasm3.py

@@ -16,6 +16,7 @@
 from openqasm3.printer import dumps
 
 from pyqasm.modules.base import QasmModule
+from pyqasm.printer import draw
 
 
 class Qasm3Module(QasmModule):
@@ -48,3 +49,7 @@ def accept(self, visitor):
         final_stmt_list = visitor.finalize(unrolled_stmt_list)
 
         self._unrolled_ast.statements = final_stmt_list
+
+    def draw(self):
+        """Draw the module"""
+        return draw(self)

src/pyqasm/printer.py

@@ -0,0 +1,297 @@
+# Copyright (C) 2024 qBraid
+#
+# This file is part of pyqasm
+#
+# Pyqasm is free software released under the GNU General Public License v3
+# or later. You can redistribute and/or modify it under the terms of the GPL v3.
+# See the LICENSE file in the project root or <https://www.gnu.org/licenses/gpl-3.0.html>.
+#
+# THERE IS NO WARRANTY for pyqasm, as per Section 15 of the GPL v3.
+
+"""
+Module with analysis functions for QASM visitor
+
+"""
+from __future__ import annotations
+
+from typing import TYPE_CHECKING, Any, Optional, Union
+
+import matplotlib as mpl
+import openqasm3.ast as ast
+from matplotlib import pyplot as plt
+
+from pyqasm.expressions import Qasm3ExprEvaluator
+from pyqasm.maps import (
+    FIVE_QUBIT_OP_MAP,
+    FOUR_QUBIT_OP_MAP,
+    ONE_QUBIT_OP_MAP,
+    ONE_QUBIT_ROTATION_MAP,
+    REV_CTRL_GATE_MAP,
+    THREE_QUBIT_OP_MAP,
+    TWO_QUBIT_OP_MAP,
+)
+
+if TYPE_CHECKING:
+    from pyqasm.modules.base import Qasm3Module
+
+DEFAULT_GATE_COLOR = "#d4b6e8"
+HADAMARD_GATE_COLOR = "#f0a6a6"
+
+GATE_BOX_WIDTH, GATE_BOX_HEIGHT = 0.6, 0.6
+GATE_SPACING = 0.2
+LINE_SPACING = 0.6
+TEXT_MARGIN = 0.6
+FRAME_PADDING = 0.2
+
+
+def draw(module: Qasm3Module, output="mpl"):
+    if output == "mpl":
+        return _draw_mpl(module)
+    else:
+        raise NotImplementedError(f"{output} drawing for Qasm3Module is unsupported")
+
+
+def _draw_mpl(module: Qasm3Module) -> plt.Figure:
+    module.unroll()
+    module.remove_includes()
+    module.remove_barriers()
+
+    n_lines = module._num_qubits + module._num_clbits
+    statements = module._statements
+
+    # compute line numbers per qubit + max depth
+    line_nums = dict()
+    line_num = -1
+    max_depth = 0
+
+    for clbit_reg in module._classical_registers.keys():
+        size = module._classical_registers[clbit_reg]
+        line_num += size
+        for i in range(size):
+            line_nums[(clbit_reg, i)] = line_num
+            line_num -= 1
+        line_num += size
+
+    for qubit_reg in module._qubit_registers.keys():
+        size = module._qubit_registers[qubit_reg]
+        line_num += size
+        for i in range(size):
+            line_nums[(qubit_reg, i)] = line_num
+            depth = module._qubit_depths[(qubit_reg, i)]._total_ops()
+            max_depth = max(max_depth, depth)
+            line_num -= 1
+        line_num += size
+
+    # compute moments
+    depths = dict()
+    for k in line_nums.keys():
+        depths[k] = -1
+
+    moments = []
+    for statement in statements:
+        if "Declaration" in str(type(statement)):
+            continue
+        if isinstance(statement, ast.QuantumGate):
+            qubits = [_identifier_to_key(q) for q in statement.qubits]
+            depth = 1 + max([depths[q] for q in qubits])
+            for q in qubits:
+                depths[q] = depth
+        elif isinstance(statement, ast.QuantumMeasurementStatement):
+            qubit_key = _identifier_to_key(statement.measure.qubit)
+            target_key = _identifier_to_key(statement.target)
+            depth = 1 + max(depths[qubit_key], depths[target_key])
+            for k in [qubit_key, target_key]:
+                depths[k] = depth
+        elif isinstance(statement, ast.QuantumBarrier):
+            pass
+        elif isinstance(statement, ast.QuantumReset):
+            pass
+        else:
+            raise NotImplementedError(f"Unsupported statement: {statement}")
+
+        if depth >= len(moments):
+            moments.append([])
+        moments[depth].append(statement)
+
+    width = 0
+    for moment in moments:
+        width += _mpl_get_moment_width(moment)
+    width += TEXT_MARGIN
+
+    fig, ax = plt.subplots(
+        figsize=(width, n_lines * GATE_BOX_HEIGHT + LINE_SPACING * (n_lines - 1))
+    )
+    ax.set_ylim(
+        -GATE_BOX_HEIGHT / 2 - FRAME_PADDING / 2,
+        n_lines * GATE_BOX_HEIGHT
+        + LINE_SPACING * (n_lines - 1)
+        - GATE_BOX_HEIGHT / 2
+        + FRAME_PADDING / 2,
+    )
+    ax.set_xlim(-FRAME_PADDING / 2, width)
+    ax.axis("off")
+    # ax.set_aspect('equal')
+    # plt.tight_layout()
+
+    x = 0
+    for k in module._qubit_registers.keys():
+        for i in range(module._qubit_registers[k]):
+            line_num = line_nums[(k, i)]
+            _mpl_draw_qubit_label((k, i), line_num, ax, x)
+    for k in module._classical_registers.keys():
+        for i in range(module._classical_registers[k]):
+            line_num = line_nums[(k, i)]
+            _mpl_draw_clbit_label((k, i), line_num, ax, x)
+    x += TEXT_MARGIN
+    x0 = x
+    for moment in moments:
+        dx = _mpl_get_moment_width(moment)
+        _mpl_draw_lines(dx, line_nums, ax, x)
+        x += dx
+    x = x0
+    for moment in moments:
+        dx = _mpl_get_moment_width(moment)
+        for statement in moment:
+            _mpl_draw_statement(statement, line_nums, ax, x)
+        x += dx
+
+    return fig
+
+
+def _identifier_to_key(identifier: ast.Identifier | ast.IndexedIdentifier) -> tuple[str, int]:
+    if isinstance(identifier, ast.Identifier):
+        return identifier.name, -1
+    else:
+        return (
+            identifier.name.name,
+            Qasm3ExprEvaluator.evaluate_expression(identifier.indices[0][0])[0],
+        )
+
+
+def _mpl_line_to_y(line_num: int) -> float:
+    return line_num * (GATE_BOX_HEIGHT + LINE_SPACING)
+
+
+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_clbit_label(clbit: tuple[str, int], line_num: int, ax: plt.Axes, x: float):
+    ax.text(x, _mpl_line_to_y(line_num), f"{clbit[0]}[{clbit[1]}]", ha="right", va="center")
+
+
+def _mpl_draw_lines(width, line_nums: dict[tuple[str, int], int], ax: plt.Axes, x: float):
+    for k in line_nums.keys():
+        y = _mpl_line_to_y(line_nums[k])
+        ax.hlines(
+            xmin=x - width / 2, xmax=x + width / 2, y=y, color="black", linestyle="-", zorder=-10
+        )
+
+
+def _mpl_get_moment_width(moment: list[ast.QuantumStatement]) -> float:
+    return max([_mpl_get_statement_width(s) for s in moment])
+
+
+def _mpl_get_statement_width(statement: ast.QuantumStatement) -> float:
+    return GATE_BOX_WIDTH + GATE_SPACING
+
+
+def _mpl_draw_statement(
+    statement: ast.QuantumStatement, line_nums: dict[tuple[str, int], int], ax: plt.Axes, x: float
+):
+    if isinstance(statement, ast.QuantumGate):
+        args = [Qasm3ExprEvaluator.evaluate_expression(arg)[0] for arg in statement.arguments]
+        lines = [line_nums[_identifier_to_key(q)] for q in statement.qubits]
+        _mpl_draw_gate(statement, args, lines, ax, x)
+    elif isinstance(statement, ast.QuantumMeasurementStatement):
+        qubit_key = _identifier_to_key(statement.measure.qubit)
+        target_key = _identifier_to_key(statement.target)
+        _mpl_draw_measurement(line_nums[qubit_key], line_nums[target_key], ax, x)
+    else:
+        raise NotImplementedError(f"Unsupported statement: {statement}")
+
+
+def _mpl_draw_gate(
+    gate: ast.QuantumGate, args: list[Any], lines: list[int], ax: plt.Axes, x: float
+):
+    name = gate.name.name
+    if name in REV_CTRL_GATE_MAP:
+        i = 0
+        while name in REV_CTRL_GATE_MAP:
+            name = REV_CTRL_GATE_MAP[name]
+            _draw_mpl_control(lines[i], lines[-1], ax, x)
+            i += 1
+        lines = lines[i:]
+        gate.name.name = name
+
+    if name in ONE_QUBIT_OP_MAP or name in ONE_QUBIT_ROTATION_MAP:
+        _draw_mpl_one_qubit_gate(gate, args, lines[0], ax, x)
+    elif name in TWO_QUBIT_OP_MAP:
+        if name == "swap":
+            _draw_mpl_swap(lines[0], lines[1], ax, x)
+        else:
+            raise NotImplementedError(f"Unsupported gate: {name}")
+    else:
+        raise NotImplementedError(f"Unsupported gate: {name}")
+
+
+# TODO: switch to moment based system. go progressively, calculating required width for each moment, center the rest. this makes position calculations not to bad. if we overflow, start a new figure.
+
+
+def _draw_mpl_one_qubit_gate(
+    gate: ast.QuantumGate, args: list[Any], line: int, ax: plt.Axes, x: float
+):
+    color = DEFAULT_GATE_COLOR
+    if gate.name.name == "h":
+        color = HADAMARD_GATE_COLOR
+    text = gate.name.name.upper()
+    if len(args) > 0:
+        text += f"\n({', '.join([f'{a:.3f}' if isinstance(a, float) else str(a) for a in args])})"
+
+    y = _mpl_line_to_y(line)
+    rect = plt.Rectangle(
+        (x - GATE_BOX_WIDTH / 2, y - GATE_BOX_HEIGHT / 2),
+        GATE_BOX_WIDTH,
+        GATE_BOX_HEIGHT,
+        facecolor=color,
+        edgecolor="none",
+    )
+    ax.add_patch(rect)
+    ax.text(x, y, text, ha="center", va="center")
+
+
+def _draw_mpl_control(ctrl_line: int, target_line: int, ax: plt.Axes, x: float):
+    y1 = _mpl_line_to_y(ctrl_line)
+    y2 = _mpl_line_to_y(target_line)
+    ax.vlines(x=x, ymin=min(y1, y2), ymax=max(y1, y2), color="black", linestyle="-", zorder=-1)
+    ax.plot(x, y1, "ko", markersize=8, markerfacecolor="black")
+
+
+def _draw_mpl_swap(line1: int, line2: int, ax: plt.Axes, x: float):
+    y1 = _mpl_line_to_y(line1)
+    y2 = _mpl_line_to_y(line2)
+    ax.vlines(x=x, ymin=min(y1, y2), ymax=max(y1, y2), color="black", linestyle="-")
+    ax.plot(x, y1, "x", markersize=8, color="black")
+    ax.plot(x, y2, "x", markersize=8, color="black")
+
+
+def _mpl_draw_measurement(qbit_line: int, cbit_line: int, ax: plt.Axes, x: float):
+    y1 = _mpl_line_to_y(qbit_line)
+    y2 = _mpl_line_to_y(cbit_line)
+
+    rect = plt.Rectangle(
+        (x - GATE_BOX_WIDTH / 2, y1 - GATE_BOX_HEIGHT / 2),
+        GATE_BOX_WIDTH,
+        GATE_BOX_HEIGHT,
+        facecolor="gray",
+        edgecolor="none",
+    )
+    ax.add_patch(rect)
+    ax.text(x, y1, "M", ha="center", va="center")
+    ax.vlines(
+        x=x - 0.025, ymin=min(y1, y2), ymax=max(y1, y2), color="gray", linestyle="-", zorder=-1
+    )
+    ax.vlines(
+        x=x + 0.025, ymin=min(y1, y2), ymax=max(y1, y2), color="gray", linestyle="-", zorder=-1
+    )
+    ax.plot(x, y2 + 0.1, "v", markersize=16, color="gray")