anglr

Planar angle mathematics library for Python.

This library contains many different functions for converting between units, comparing angles, and doing angle arithmetic.

Links:

• PyPI
• GitHub

Quickstart: pip3 install anglr.

Rationale

Consider the following trivial angle comparison code:

import math
heading = get_compass_value() # angle in radians normalized to $[0, 2*pi)$
if target - math.pi / 4 <= heading <= target + math.pi / 4:
    print("Facing the target")
else:
    print("Not facing the target")

Angle code is everywhere. The above is totally, utterly wrong (consider what happens when target is 0), yet this could easily be overlooked while writing and during code review.

With anglr, there is a better way:

import math
from anglr import Angle
heading = Angle(get_compass_value())
if heading.angle_between(target) <= math.pi / 4:
    print("Facing the target")
else:
    print("Not facing the target")

Much better - this will now correctly take modular arithmetic into account when comparing angles.

Examples

Angle creation:

from math import pi
from anglr import Angle
print(Angle())
print(Angle(87 * pi / 2))
print(Angle(pi / 2, "radians"))
print(Angle(Angle(pi / 2, "radians"))) # same as above
print(Angle(64.2, "degrees"))
print(Angle(384.9, "gradians"))
print(Angle(4.5, "hours"))
print(Angle(203.8, "arcminutes"))
print(Angle(42352.7, "arcseconds"))
print(Angle((56, 32), "vector")) # angle in standard position - counterclockwise from positive X-axis

Angle conversion:

from anglr import Angle
x = Angle(58.3)
print([x], str(x), x.radians, x.degrees, x.gradians, x.hours, x.arcminutes, x.arcseconds, x.vector, x.x, x.y)
print(complex(x))
print(float(x))
print(int(x))
x.radians = pi / 2
print(x.dump())
x.degrees = 64.2
print(x.dump())
x.gradians = 384.9
print(x.dump())
x.hours = 4.5
print(x.dump())
x.arcminutes = 203.8
print(x.dump())
x.arcseconds = 42352.7
print(x.dump())
x.vector = (56, 32)
print(x.dump())

Angle arithmetic:

from math import pi
from anglr import Angle
print(Angle(pi / 6) + Angle(2 * pi / 3))
print(x * 2 + Angle(3 * pi / 4) / 4 + 5 * Angle(pi / 3))
print(-abs(+Angle(pi)))
print(round(Angle(-75.87)))
print(Angle(-4.3) <= Angle(pi / 4) > Angle(0.118) == Angle(0.118))

print("0 to 2pi sanity checks")
print(Angle(0).normalized(0,2*pi)) # 0 as provided
print(Angle(pi).normalized(0,2*pi)) # pi as provided
print(Angle(-pi).normalized(0,2*pi)) # wrap to pi
print(Angle(7*pi).normalized(2*pi,0)) # same as above despite range out of order
print("\ndefault args and wrapping")
print(Angle(-7.5*pi).normalized())
print(Angle(-7.5*pi).normalized(0)) # same as above
print(Angle(-7.5*pi).normalized(0,2*pi)) # same as above
print(Angle(-8.25*pi).normalized(0,2*pi)) # wrap beyond above to cross Tau
print(Angle(8.25*pi).normalized(0,2*pi)) # cross over other way
print("\n-pi to pi")
print(Angle(0).normalized(-pi,pi)) #sanity check
print(Angle(-7.5*pi).normalized(-pi,pi))
print(Angle(-8.25*pi).normalized(-pi,pi)) # cross over
print("\n-pi to 0") # not sure why this normalization range is useful or if results are valid:
print(Angle(0).normalized(-pi,0))
print(Angle(-pi/2).normalized(-pi,0))
print(Angle(pi/2).normalized(-pi,0))
print("\nbecause we like gradians?")
print(Angle(-870.3, "gradians").normalized(0, 2 * pi))
print(Angle(-870.3, "gradians").normalized(-pi, pi))
print(Angle(-870.3, "gradians").normalized(-pi, 0))

print(Angle(1, "degrees").angle_between_clockwise(Angle(0, "degrees")))
print(Angle(1, "degrees").angle_between(Angle(0, "degrees")))
print(Angle(0, "degrees").angle_within(Angle(-45, "degrees"), Angle(45, "degrees")))
print(Angle(-1, "degrees").angle_within(Angle(-1, "degrees"), Angle(1, "degrees"), strictly_within=True))
print(Angle(-1, "degrees").angle_to(Angle(180, "degrees")))
print(Angle(0, "degrees").angle_to(Angle(180, "degrees")))

To run all of the above as tests, simply run python3 tests.py in the project directory.

Installing

** THIS VERSION IS NOT AVAILABLE IN PIP YET - IGNORE BELOW ** The easiest way to install this is using pip3 install anglr.

Otherwise, download the source distribution from PyPI, and extract the archive.

In the folder, run python3 setup.py install.

Requirements

This library requires Python 3.2 or higher to run.

Authors

Uberi <azhang9@gmail.com> (Anthony Zhang)
Pondersome <karim@compuguru.com> (Karim Virani)

Please report bugs and suggestions at the issue tracker!

License

Copyright 2014-2015 Anthony Zhang (Uberi).

The source code is available online at GitHub.

This program is made available under the 3-clause BSD license. See LICENSE.txt for more information.