# PiecewiseLinearPauliRotations

*class *`PiecewiseLinearPauliRotations(num_state_qubits=None, breakpoints=None, slopes=None, offsets=None, basis='Y', name='pw_lin')`

Bases: `qiskit.circuit.library.arithmetic.functional_pauli_rotations.FunctionalPauliRotations`

Piecewise-linearly-controlled Pauli rotations.

For a piecewise linear (not necessarily continuous) function $f(x)$, which is defined through breakpoints, slopes and offsets as follows. Suppose the breakpoints $(x_0, ..., x_J)$ are a subset of $[0, 2^n-1]$, where $n$ is the number of state qubits. Further on, denote the corresponding slopes and offsets by $a_j$ and $b_j$ respectively. Then f(x) is defined as:

$\begin{split}f(x) = \begin{cases} 0, x < x_0 \\ a_j (x - x_j) + b_j, x_j \leq x < x_{j+1} \end{cases}\end{split}$where we implicitly assume $x_{J+1} = 2^n$.

Construct piecewise-linearly-controlled Pauli rotations.

**Parameters**

**num_state_qubits**(`Optional`

[`int`

]) – The number of qubits representing the state.**breakpoints**(`Optional`

[`List`

[`int`

]]) – The breakpoints to define the piecewise-linear function. Defaults to`[0]`

.**slopes**(`Optional`

[`List`

[`float`

]]) – The slopes for different segments of the piecewise-linear function. Defaults to`[1]`

.**offsets**(`Optional`

[`List`

[`float`

]]) – The offsets for different segments of the piecewise-linear function. Defaults to`[0]`

.**basis**(`str`

) – The type of Pauli rotation (`'X'`

,`'Y'`

,`'Z'`

).**name**(`str`

) – The name of the circuit.

## Methods Defined Here

### evaluate

`PiecewiseLinearPauliRotations.evaluate(x)`

Classically evaluate the piecewise linear rotation.

**Parameters**

**x** (`float`

) – Value to be evaluated at.

**Return type**

`float`

**Returns**

Value of piecewise linear function at x.

## Attributes

### ancillas

Returns a list of ancilla bits in the order that the registers were added.

**Return type**

`List`

[`AncillaQubit`

]

### basis

The kind of Pauli rotation to be used.

Set the basis to ‘X’, ‘Y’ or ‘Z’ for controlled-X, -Y, or -Z rotations respectively.

**Return type**

`str`

**Returns**

The kind of Pauli rotation used in controlled rotation.

### breakpoints

The breakpoints of the piecewise linear function.

The function is linear in the intervals `[point_i, point_{i+1}]`

where the last point implicitly is `2**(num_state_qubits + 1)`

.

**Return type**

`List`

[`int`

]

### calibrations

Return calibration dictionary.

The custom pulse definition of a given gate is of the form `{'gate_name': {(qubits, params): schedule}}`

**Return type**

`dict`

### clbits

### contains_zero_breakpoint

Whether 0 is the first breakpoint.

**Return type**

`bool`

**Returns**

True, if 0 is the first breakpoint, otherwise False.

### data

### extension_lib

Default value: `'include "qelib1.inc";'`

### global_phase

### header

Default value: `'OPENQASM 2.0;'`

### instances

Default value: `2591`

### mapped_offsets

The offsets mapped to the internal representation.

**Return type**

`List`

[`float`

]

**Returns**

The mapped offsets.

### mapped_slopes

The slopes mapped to the internal representation.

**Return type**

`List`

[`float`

]

**Returns**

The mapped slopes.

### metadata

The user provided metadata associated with the circuit

The metadata for the circuit is a user provided `dict`

of metadata for the circuit. It will not be used to influence the execution or operation of the circuit, but it is expected to be passed between all transforms of the circuit (ie transpilation) and that providers will associate any circuit metadata with the results it returns from execution of that circuit.

**Return type**

`dict`

### num_ancilla_qubits

The minimum number of ancilla qubits in the circuit.

**Return type**

`int`

**Returns**

The minimal number of ancillas required.

### num_ancillas

Return the number of ancilla qubits.

**Return type**

`int`

### num_clbits

Return number of classical bits.

**Return type**

`int`

### num_parameters

**Return type**

`int`

### num_qubits

Return number of qubits.

**Return type**

`int`

### num_state_qubits

The number of state qubits representing the state $|x\rangle$.

**Return type**

`int`

**Returns**

The number of state qubits.

### offsets

The breakpoints of the piecewise linear function.

The function is linear in the intervals `[point_i, point_{i+1}]`

where the last point implicitly is `2**(num_state_qubits + 1)`

.

**Return type**

`List`

[`float`

]

### op_start_times

Return a list of operation start times.

This attribute is enabled once one of scheduling analysis passes runs on the quantum circuit.

**Return type**

`List`

[`int`

]

**Returns**

List of integers representing instruction start times. The index corresponds to the index of instruction in `QuantumCircuit.data`

.

**Raises**

**AttributeError** – When circuit is not scheduled.

### parameters

**Return type**

`ParameterView`

### prefix

Default value: `'circuit'`

### qregs

A list of the quantum registers associated with the circuit.

### qubits

### slopes

The breakpoints of the piecewise linear function.

The function is linear in the intervals `[point_i, point_{i+1}]`

where the last point implicitly is `2**(num_state_qubits + 1)`

.

**Return type**

`List`

[`int`

]