qpandalite.circuit_builder.parameter module

Symbolic parameters for parametric quantum circuits.

This module provides: - Parameter: Named symbolic parameter for parametric gates - Parameters: Array of named parameters with indexing support

These classes enable symbolic expressions for gate parameters that can be bound to concrete values at execution time.

Example usage:

theta = Parameter("theta") phi = Parameter("phi")

# Arithmetic operations create symbolic expressions expr = theta + phi / 2

# Bind values and evaluate theta.bind(1.0) phi.bind(2.0) result = expr.evalf() # 2.0

class qpandalite.circuit_builder.parameter.Parameter(name)

基类：object

Named symbolic parameter for parametric quantum circuits.

Parameter supports arithmetic operations that create symbolic expressions using sympy. The parameter can be bound to a concrete value or evaluated with a provided values dictionary.

参数:

name (str)

name

Parameter name

symbol

Underlying sympy Symbol

示例

>>> theta = Parameter("theta")
>>> phi = Parameter("phi")
>>> expr = theta * 2 + phi
>>> # Evaluate with concrete values
>>> float(expr.subs({theta.symbol: 1.0, phi.symbol: 0.5}))
2.5

bind(value)

Bind a concrete value to this parameter.

参数:

value (float) -- The numeric value to bind

返回类型:

None

evaluate(values=None)

Evaluate the parameter.

If the parameter is bound, returns the bound value. Otherwise, looks up the value in the provided dictionary.

参数:

values (dict[str, float] | None) -- Optional dictionary mapping parameter names to values

返回:

The evaluated numeric value

抛出:

ValueError -- If parameter is not bound and not in values dict

返回类型:

float

property is_bound: bool

Check if the parameter has a bound value.

property name: str

property symbol: Symbol

class qpandalite.circuit_builder.parameter.Parameters(name, size)

基类：object

Array of named parameters with indexing support.

Creates multiple Parameter objects with names "{name}_{index}".

参数:

• name (str)

• size (int)

name

Base name for the parameter array

示例

>>> alphas = Parameters("alpha", size=4)
>>> alphas[0]
Parameter('alpha_0')
>>> alphas.names
['alpha_0', 'alpha_1', 'alpha_2', 'alpha_3']
>>> alphas.bind([0.1, 0.2, 0.3, 0.4])
>>> alphas[0].evaluate()
0.1

bind(values)

Bind values to all parameters.

参数:

values (list[float]) -- List of values (must match array size)

抛出:

ValueError -- If values length doesn't match array size

返回类型:

None

evaluate(values=None)

Evaluate all parameters.

参数:

values (list[float] | None) -- Optional list of values to use (must match array size)

返回:

List of evaluated values

返回类型:

list[float]

property name: str

property names: list[str]

Return list of all parameter names.

property symbols: list[Symbol]

Return list of all sympy symbols.