OptimizationFlag

full name: tenpy.tools.optimization.OptimizationFlag
parent module: tenpy.tools.optimization
type: class

Inheritance Diagram

Methods

`OptimizationFlag.conjugate`	Returns self, the complex conjugate of any int.
`OptimizationFlag.bit_length`()	Number of bits necessary to represent self in binary.
`OptimizationFlag.bit_count`()	Number of ones in the binary representation of the absolute value of self.
`OptimizationFlag.to_bytes`([length, ...])	Like `int.to_bytes`, which has a docstring which sphinx cant parse
`OptimizationFlag.from_bytes`(bytes, byteorder, *)	Like `int.from_bytes`, which has a docstring which sphinx cant parse
`OptimizationFlag.as_integer_ratio`()	Return integer ratio.
`OptimizationFlag.__init__`(args, *kwds)

Class Attributes and Properties

`OptimizationFlag.real`	the real part of a complex number
`OptimizationFlag.imag`	the imaginary part of a complex number
`OptimizationFlag.numerator`	the numerator of a rational number in lowest terms
`OptimizationFlag.denominator`	the denominator of a rational number in lowest terms
`OptimizationFlag.none`
`OptimizationFlag.default`
`OptimizationFlag.safe`
`OptimizationFlag.skip_arg_checks`

class tenpy.tools.optimization.OptimizationFlag(value, names=None, *, module=None, qualname=None, type=None, start=1, boundary=None)[source]

Bases: IntEnum

Options for the global ‘optimization level’ used for dynamical optimizations.

Whether we optimize dynamically is decided by comparison of the global “optimization level” with one of the following flags. A higher level includes all the previous optimizations.

Level	Flag	Description
0	none	Don’t do any optimizations, i.e., run many sanity checks. Used for testing.
1	default	Skip really unnecessary sanity checks, but also don’t try any optional optimizations if they might give an overhead.
2	safe	Activate safe optimizations in algorithms, even if they might give a small overhead. Example: Try to compress the MPO representing the hamiltonian.
3	skip_arg_checks	Unsafe! Skip (some) class sanity tests and (function) argument checks.

Warning

When unsafe optimizations are enabled, errors will not be detected that easily, debugging is much harder, and you might even get segmentation faults in the compiled parts. Use this kind of optimization only for code which you successfully ran before with (very) similar parameters and disabled optimizations! Enable this optimization only during the parts of the code where it is really necessary. Check whether it actually helps - if it doesn’t, keep the optimization disabled!

classmethod from_bytes(bytes, byteorder, *, signed=False)[source]: Like int.from_bytes, which has a docstring which sphinx cant parse

to_bytes(length=1, byteorder='big', *, signed=False)[source]: Like int.to_bytes, which has a docstring which sphinx cant parse

conjugate(): Returns self, the complex conjugate of any int.

bit_length()

Number of bits necessary to represent self in binary.

>>> bin(37)
'0b100101'
>>> (37).bit_length()
6

bit_count()

Number of ones in the binary representation of the absolute value of self.

Also known as the population count.

>>> bin(13)
'0b1101'
>>> (13).bit_count()
3

as_integer_ratio()

Return integer ratio.

Return a pair of integers, whose ratio is exactly equal to the original int and with a positive denominator.

>>> (10).as_integer_ratio()
(10, 1)
>>> (-10).as_integer_ratio()
(-10, 1)
>>> (0).as_integer_ratio()
(0, 1)

real: the real part of a complex number

imag: the imaginary part of a complex number

numerator: the numerator of a rational number in lowest terms

denominator: the denominator of a rational number in lowest terms