Draw circuit without passing circuit arguments

Feature details

Currently, to draw a circuit, we need to pass the inputs which are then used in the circuit drawing. I suggest having a general circuit drawing function that can draw the circuit without those inputs. Instead of showing the angles of rotation, for example, it can simply say which type of rotation gate it is. We can then have a general circuit. Not a parameterized one.

Implementation

Drawing capability is already there. Just need to modify it such that circuit.draw() will draw a general circuit if no parameters have been passed, instead of raising an error. If parameters are given, circuit.draw() will function as it does now and circuit.draw(parametric=False) will draw the general circuit.

How important would you say this feature is?

1: Not important. Would be nice to have.

Additional information

#1484 is somewhat related. It enables drawing of mpl circuits. Not sure if will draw general circuits or not. If not, this issue can also be added for that. Parameterized circuits are good but general circuits are also needed.

[ankit27kh]

Hello @albi3ro! Thanks for this! And also for the wonderful mpl drawer! Great addition!

[albi3ro]

@ankit27kh

As long as the values don’t have any classical processing (like x+y or if x), then strings can be used in place of numbers in the current circuit drawer.

@qml.qnode(qml.device('default.qubit', wires=1))
def circ(x):
    qml.RX(x, wires=0)
    return qml.expval(qml.PauliZ(0))

print(qml.draw(circ)('x'))

0: ──RX(x)─┤  <Z>

Does this provide what you wanted? It won’t work in all situations, but hopefully will be useful enough for most.