quantum-computing

Several katas could have better error messaging:

• Superposition : the test harness could log the actual state of the system after prep vs the expected state before asserting that they are the same (the change would add state prep and logging using DumpMachine to AssertEqualOnZeroState)
• BasicGates : a similar improvement, but a bit more extra code to write a unified test wrapper

Here are some examples:

• Root README is missing machine learning category of samples
• README in algorithms is missing repeat-until-success and sudoku-grover
• [README in diagnostics](https://github.com/microsoft/Quantum/blob/main/samples/diagnostics/RE

What is the expected enhancement?

when reading source code that is related to some circuits, it is often useful to be able to see the circuit.

examples are transpiler tests (which claim two pre-/post-transpile circuits are equivalent), and circuit equivalence libraries.

Examples of files that have this already:
https://github.com/Qiskit/qiskit-terra/blob/main/test/python/transpiler/te

Is your feature request related to a use case or problem? Please describe.

Describe the solution you'd like
Heatmaps are often useful to visualize error metrics for qubits and couplers on the google devices. When selecting a subset of qubits to run an experiment on; it's useful to consult heatmaps of error metrics. We should add an option to the cirq.Heatmap and `cirq.TwoQubitInter

To get this codebase up to standard, we need to add type hints. At the very least, perhaps we should start insisting that all new code has type hints added, but moreover we need to add typing to the code that currently exists.

This is a pretty large project, but luckily it can be done incrementally - I believe at this point it's a stretch goal for v1, if anyone wants to help it would be much ap

Is your feature request related to a problem? Please describe.
I would like to check the behavior of the parameter index in the function QubitCircuit.add_gate()

In qutip.qip.QubitCircuit.add_gate(), there is a optional list type attribute called index.
This seems to be used to insert gates in the middle of the gate list (qutip.qip.QubitCircuit.gates).
The corresponding code is

Expected behavior

import pennylane as qml
dev = qml.device("default.qubit", wires=5, shots=5)


@qml.qnode(dev)
def circuit():
    return qml.sample()


def main():
    print(circuit())
    print(qml.draw(circuit, show_all_wires=True)())
    return


if __name__ == "__main__":
    main()

Expect something like this:

[[0 0 0 0 0]
 [0 0 0 0 0]
 [0 0 0 0 0

For example, pylint would have caught ProjectQ-Framework/ProjectQ#19 via an undefined variable warning.

The grammar was extended with some built-in math functions that were out of the specification. TSC decided that the functions included in Qiskit/openqasm#275 should be part of the specification.

Describe the issue

The implementation of the modulo gate used in the Shor's algorithm section is the following:

def c_amod15(a, power):
    """Controlled multiplication by a mod 15"""
    if a not in [2,7,8,11,13]:
        raise ValueError("'a' must be 2,7,8,11 or 13")
    U = QuantumCircuit(4)        
    for iteration in range(power):
        if a in [2,13]:
            U.s

The formulas at API page for https://docs.microsoft.com/en-us/qsharp/api/qsharp/microsoft.quantum.preparation.purifiedmixedstatewithdata are also broken, but I couldn't figure out what caused it at a glance.

Originally posted by @tcNickolas in microsoft/QuantumLibraries#484 (comment)

right now, absolute jumps are conflated in the label object here. I'd prefer we instead introduce a new object called absolute-program-location or something like that. (I don't want to use "address" only because it feels too dishonest.) If we do this, then we'd change patch-labels to not overwrite these label objects, and we'