Matrix

>>> import perceval as pcvl
>>> M = pcvl.Matrix("1 2 3\n4 5 6\n7 8 9")
>>> print(M.pdisplay())
⎡1  2  3⎤
⎢4  5  6⎥
⎣7  8  9⎦
>>> M.is_unitary()
False

Parameter

class perceval.utils.parameter.Parameter(name, value=None, min_v=None, max_v=None, periodic=True)

A Parameter is a used as a variable in a circuit definition

Parameters are a simple way to introduce named variables in a circuit. They take floating number values. When non defined they are associated to sympy symbols and will be used to perform symbolic calculations.

Parameters:

name (str) – name of the parameter
value (Optional[float]) – optional value, when the value is provided at initialization, the parameter is considered as fixed
min_v (Optional[float]) – minimal value that the parameter can take, is used in circuit optimization
max_v (Optional[float]) – maximal value that the parameter can take, is used in circuit optimization
periodic (bool) – True if the parameter is periodic, False otherwise (default True)

property bounds: tuple[float, float]: Minimal and maximal values for the parameter

property defined: bool: Return True if the parameter has a value (fixed or non fixed)

evalf(subs=None)

Convert the parameter to float, will fail if the parameter has no defined value

Return type:: float

fix_value(v)

Fix the value of a non-fixed Parameter. The Parameter is not variable afterwards.

Parameters:: v (float) – the numerical value

property fixed: bool: Return True if the parameter is fixed

property is_periodic: bool: Return True if the parameter is defined as a period parameter

property is_variable: bool: Returns True for a non-fixed parameter

property max: float: The maximal value of the parameter

property min: The minimal value of the parameter

property pid: Unique identifier for the parameter

reset(): Reset the value of a non-fixed parameter

set_periodic(periodic): set periodic flag

set_value(v, force=False)

Define the numerical value of a Parameter

Parameters:

v (float) – the numerical value
force (bool) – enable to change the value of a fixed parameter

Raise:

RuntimeError if the parameter is fixed

property spv: Expr: The current value of the parameter defined as a sympy expression

Expression

class perceval.utils.parameter.Expression(name, parameters)

Symbolic math expression This class allows arithmetic manipulation of the Parameter class.

Example:

>>> p_a = Parameter("A")
>>> p_b = Parameter("B")
>>> sum_ab = Expression("A**2 + B", {p_a, p_b})
>>> p_a.set_value(2)
>>> p_b.set_value(3)
>>> print(float(sum_ab))  # Prints 7.0

Parameters:

name (str) – string specifying equation, acts as name of Expression parameter.
parameters (set[Parameter]) – set of sub parameter instances used in the expression

property defined: bool: Return True if the parameter has a value (fixed or non fixed)

property is_periodic: bool: Expressions are not considered periodic

property parameters: list[perceval.utils.parameter.Parameter]: Returns list of sub parameters in alphabetical order