qml.resource.SpectralNormError

class SpectralNormError(error)

Bases: AlgorithmicError

Class representing the spectral norm error.

The spectral norm error is defined as the distance, in spectral norm, between the true unitary we intend to apply and the approximate unitary that is actually applied.

Parameters:

error (float) – The numerical value of the error

Example

>>> s1 = SpectralNormError(0.01)
>>> s2 = SpectralNormError(0.02)
>>> s1.combine(s2)
SpectralNormError(0.03)

Methods

combine(other)	Combine two spectral norm errors.
get_error(approximate_op, exact_op)	Compute spectral norm error between two operators.

combine(other)

Combine two spectral norm errors.

Parameters:

other (SpectralNormError) – The other instance of error being combined.

Returns:

The total error after combination.

Return type:

SpectralNormError

Example

>>> s1 = SpectralNormError(0.01)
>>> s2 = SpectralNormError(0.02)
>>> s1.combine(s2)
SpectralNormError(0.03)

static get_error(approximate_op, exact_op)

Compute spectral norm error between two operators.

Parameters:

• approximate_op (Operator) – The approximate operator.

• exact_op (Operator) – The exact operator.

Returns:

The error between the exact operator and its approximation.

Return type:

float

Example

>>> Op1 = qml.RY(0.40, 0)
>>> Op2 = qml.RY(0.41, 0)
>>> SpectralNormError.get_error(Op1, Op2)
0.004999994791668309

code/api/pennylane.resource.SpectralNormError

 

Download Python script

 

Download Notebook

 

View on GitHub