ReadoutError

class ReadoutError(probabilities, atol=1e-08)

Bases: object

Readout error class for Qiskit Aer noise model.

Create a readout error for a noise model.

For an N-qubit readout error probabilities are entered as vectors:

probabilities[m] = [P(0|m), P(1|m), ..., P(2 ** N - 1|m)]

where P(n|m) is the probability of recording a noisy measurement outcome as n given the true ideal measurement outcome was m, where n and m are integer representations of bit-strings.

Example: 1-qubit

probabilities[0] = [P("0"|"0"), P("1"|"0")]
probabilities[1] = [P("0"|"1"), P("1"|"1")]

Example: 2-qubit

probabilities[0] = [P("00"|"00"), P("01"|"00"), P("10"|"00"), P("11"|"00")]
probabilities[1] = [P("00"|"01"), P("01"|"01"), P("10"|"01"), P("11"|"01")]
probabilities[2] = [P("00"|"10"), P("01"|"10"), P("10"|"10"), P("11"|"10")]
probabilities[3] = [P("00"|"11"), P("01"|"11"), P("10"|"11"), P("11"|"11")]

Parameters

• probabilities (matrix) – List of outcome assignment probabilities.

• atol (double) – Threshold for checking probabilities are normalized (Default: 1e-8).

Methods

compose	Return the composition readout error other * self.
copy	Make a copy of current ReadoutError.
dot	Return the composition readout error self * other.
expand	Return the tensor product readout error self ⊗ other.
ideal	Return True if current error object is an identity
power	Return the compose of the readout error with itself n times.
set_atol	Set the class default absolute tolerance parameter for float comparisons.
set_rtol	Set the class default relative tolerance parameter for float comparisons.
tensor	Return the tensor product readout error self ⊗ other.
to_dict	Return the current error as a dictionary.
to_instruction	Convert the ReadoutError to a circuit Instruction.

Attributes

atol

The default absolute tolerance parameter for float comparisons.

number_of_qubits

Return the number of qubits for the error.

probabilities

Return the readout error probabilities matrix.

rtol

The relative tolerance parameter for float comparisons.