misc.py

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"""
misc.py

Miscellaneous routines
"""
from numpy import sign, fmod

def bound(x, limit):
    assert limit >= 0
    if x > limit:
        return limit
    elif x < -limit:
        return -limit
    else:
        return x
    
def clip(x, low_limit, high_limit):
    assert high_limit >= low_limit
    if x < low_limit:
        return low_limit
    elif x > high_limit:
        return high_limit
    else:
        return x
    
def mod180deg(x):
    if x >= 0:
        retval = fmod(x+180.0, 360.0)-180.0
    else:
        retval = -(fmod(-x+180.0, 360.0)-180.0)
    assert -180.0 <= retval <= 180.0
    return retval
    
def deadband(x, deadband):
    if -deadband < x < deadband:
        return 0.0
    else:
        return x-sign(x)*deadband
    
if __name__ == "__main__":
    assert bound(10, 8) == 8
    assert bound(0.5, 10) == 0.5
    assert deadband(10, 2.0) == 8.0
    assert deadband(1.999, 2.0) == 0.0
    assert deadband(-10, 2.0) == -8.0
    assert deadband(-0.5, 2.0) == 0.0
    assert mod180deg(45.0) == 45.0
    assert mod180deg(179.0) == 179.0
    assert mod180deg(-179.0) == -179.0
    assert mod180deg(182.0) == -178.0
    assert mod180deg(-182.0) == 178.0
    print "all tests passed"