def test_gf2m_modmulinv__neg(self):
""" Negative tests for gf2m_modmulinv(a,f) """
# Not meant to be called with other values than int or long
self.failUnlessRaises(AttributeError, ar.gf2m_modmulinv, 0.0, 0b10011)
self.failUnlessRaises(TypeError, ar.gf2m_modmulinv, "asdf", 0b10011)
self.failUnlessEqual(ar.gf2m_modmulinv(-0b1010011,0b100011011),0b11001010)
self.failUnlessEqual(ar.gf2m_modmulinv(0b1010011,-0b100011011),0b11001010)
self.failUnlessEqual(ar.gf2m_modmulinv(-0b1010011,-0b100011011),0b11001010)
def test_gf2m_modmulinv__pos(self):
""" Positive tests for gf2m_modmulinv(a,f)
Sage test calculations::
sage: F.<y> = GF(2)[]
sage: a = y^6 + y^4 + y + 1 # a = 0b1010011
sage: b = y^7 + y^6 + y^3 + y # b = 0b11001010
sage: p = y^8 + y^4 + y^3 + y + 1 # f = 0b100011011
sage: ai = a.inverse_mod(p); ai
y^7 + y^6 + y^3 + y
sage: inverse_mod(a,p)
y^7 + y^6 + y^3 + y
sage: b == ai
True
"""
self.failUnlessEqual(ar.gf2m_modmulinv(0b1010011,0b100011011),0b11001010)
