qandle.config module

qandle.config.DEFAULT_MAPPING(x: Tensor) → Tensor

Default weight remapping function for quantum gates. This function limits the weights of the variational quantum circuit’s gates. qw_map.tanh is the default value, yielding better results in practice. For higher performance or naive usage, set DEFAULT_MAPPING = lambda x: x or DEFAULT_MAPPING = qw_map.none. For more information, see the arxiv paper 1 and arxiv paper 2.

qandle.config.DRAW_CROSS_BETWEEN_CNOT = True

Whether to draw a cross ┼ on the qubits between the CNOT control and target

>>> qandle.config.DRAW_CROSS_BETWEEN_CNOT = True
>>> print(circuit.draw())
q0─RZ─RY─RZ─■─────X─RZ─RY─RZ─■───X───
q1─RZ─RY─RZ─X─■───┼─RZ─RY─RZ─┼─■─┼─X─
q2─RZ─RY─RZ───X─■─┼─RZ─RY─RZ─X─┼─■─┼─
q3─RZ─RY─RZ─────X─■─RZ─RY─RZ───X───■─

>>> qandle.config.DRAW_CROSS_BETWEEN_CNOT = False
>>> print(circuit.draw())
q0─RZ─RY─RZ─■─────X─RZ─RY─RZ─■───X───
q1─RZ─RY─RZ─X─■─────RZ─RY─RZ───■───X─
q2─RZ─RY─RZ───X─■───RZ─RY─RZ─X───■───
q3─RZ─RY─RZ─────X─■─RZ─RY─RZ───X───■─

qandle.config.DRAW_DASH = '─'

Character used for drawing qubits, can be changed to the normal dash ‘-’, depending on font, where ─── often looks better than ---

>>> qandle.config.DRAW_DASH = "─"
>>> print(circuit.draw())
q0─RZ─RY─RZ─■─────X─RZ─RY─RZ─■───X───
q1─RZ─RY─RZ─X─■───┼─RZ─RY─RZ─┼─■─┼─X─
q2─RZ─RY─RZ───X─■─┼─RZ─RY─RZ─X─┼─■─┼─
q3─RZ─RY─RZ─────X─■─RZ─RY─RZ───X───■─

>>> qandle.config.DRAW_DASH = "-"
>>> print(circuit.draw())
q0-RZ-RY-RZ-■-----X-RZ-RY-RZ-■---X---
q1-RZ-RY-RZ-X-■---┼-RZ-RY-RZ-┼-■-┼-X-
q2-RZ-RY-RZ---X-■-┼-RZ-RY-RZ-X-┼-■-┼-
q3-RZ-RY-RZ-----X-■-RZ-RY-RZ---X---■-

qandle.config.DRAW_SHIFT_LEFT = False

Whether to shift the gates to the left if possible for a more compact drawing.

>>> qandle.config.DRAW_SHIFT_LEFT = False
>>> print(circuit.draw())
q0─RZ─RY─RZ───────────────────■───X─RZ─RY─RZ───────────────────■─X───
q1──────────RZ─RY─RZ──────────X─■─┼──────────RZ─RY─RZ──────────┼─■─X─
q2───────────────────RZ─RY─RZ───X─■───────────────────RZ─RY─RZ─X───■─

>>> qandle.config.DRAW_SHIFT_LEFT = True
>>> print(circuit.draw())
q0─RZ─RY─RZ─■───X─RZ─RY─RZ─■─X───
q1─RZ─RY─RZ─X─■─┼─RZ─RY─RZ─┼─■─X─
q2─RZ─RY─RZ───X─■─RZ─RY─RZ─X───■─

qandle.config.DRAW_SHOW_VALUES = True

Whether to show the values of the gates in the drawer. If not, only the gate positions are shown, reducing clutter.

qandle.config.DRAW_SPLITTED_PAD = 7

Number of spaces between columns in the drawer for splitted circuits.