masque/masque/utils.py
2016-03-15 19:12:39 -07:00

42 lines
965 B
Python

"""
Various helper functions
"""
from typing import Any, Union, Tuple
import numpy
# Type definitions
vector2 = Union[numpy.ndarray, Tuple[float, float]]
def is_scalar(var: Any) -> bool:
"""
Alias for 'not hasattr(var, "__len__")'
:param var: Checks if var has a length.
"""
return not hasattr(var, "__len__")
def get_bit(bit_string: Any, bit_id: int) -> bool:
"""
Returns true iff bit number 'bit_id' from the right of 'bitstring' is 1
:param bit_string: st
:param bit_id:
:return: value of the requested bit (bool)
"""
return bit_string & (1 << bit_id) != 0
def rotation_matrix_2d(theta: float) -> numpy.ndarray:
"""
2D rotation matrix for rotating counterclockwise around the origin.
:param theta: Angle to rotate, in radians
:return: rotation matrix
"""
return numpy.array([[numpy.cos(theta), -numpy.sin(theta)],
[numpy.sin(theta), +numpy.cos(theta)]])