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|
require 'test/unit'
class TestMath < Test::Unit::TestCase
#
# Check a float for approximate equality
#
# FIXME: nuke this or move it to a common location.
def assert_flequal(exp, actual, msg=nil)
assert_in_delta(exp, actual, exp == 0.0 ? 1e-7 : exp.abs/1e7, msg)
end
def test_constants
assert_flequal(3.141592654, Math::PI)
assert_flequal(2.718281828, Math::E)
end
# We're not testing the accuracy here, as much as performing some
# sanity checks
def test_fns
pi = Math::PI
pi_2 = pi / 2.0 # 90 degrees
pi_3 = pi / 3.0 # 60
pi_4 = pi / 4.0 # 45
pi_6 = pi / 6.0 # 30
ten_pi = Math::PI * 10.0
tests = {
:cos =>
[ [ 0.0, 1.0 ],
[ pi_2, 0.0 ],
[ pi_3, 0.5 ],
[ pi_4, 0.707106781 ],
[ pi_6, 0.866025402 ],
[ pi, -1.0 ],
[ 3*pi_2, 0.0 ],
[ ten_pi, 1.0 ],
[ -pi_2, 0.0 ],
[ -pi, -1.0 ],
],
:exp =>
[ [ -1.0, 0.367879441],
[ -0.5, 0.606530659],
[ 0.0, 1.0],
[ 1.0, Math::E],
[ 5.5, 244.6919323],
],
:frexp =>
[ [ 0.0, [ 0.0, 0 ]],
[ 1.0, [ 0.5, 1 ]],
[ 2.0, [ 0.5, 2 ]],
[ 8.0, [ 0.5, 4 ]],
[ 1.3, [ 0.65, 1 ]],
[-1.3, [-0.65, 1 ]],
],
:log =>
[ [ 0.5, -0.69314718],
[ 1.0, 0.0 ],
[ Math::E, 1.0 ],
[ 100, 4.605170186 ],
],
:log10 =>
[ [ 0.5, -0.301029995],
[ 1.0, 0.0 ],
[ Math::E, 0.434294481 ],
[ 100, 2.0 ],
],
:sin =>
[ [ 0.0, 0.0 ],
[ pi_2, 1.0 ],
[ pi_6, 0.5 ],
[ pi_4, 0.707106781 ],
[ pi_3, 0.866025402 ],
[ pi, 0.0 ],
[ 3*pi_2, -1.0 ],
[ ten_pi, 0.0 ],
[ -pi_2, -1.0 ],
[ -pi, 0.0 ],
],
:sqrt =>
[ [ 0.0, 0.0],
[ 1.0, 1.0],
[ 2.0, 1.414213562 ],
[ 100, 10 ],
],
:tan =>
[ [ 0.0, 0.0 ],
[ pi_6, 0.577350269 ],
[ pi_4, 1.0 ],
[ pi_3, 1.732050808 ],
[-pi_3, -1.732050808 ],
]
}
tests.each do |fn, testlist|
testlist.each do | angle, expected |
got = Math.send(fn, angle)
if expected.instance_of? Float
assert_flequal(expected, got, "Math.#{fn}(#{angle})")
else
assert_equal(expected, got, "Math.#{fn}(#{angle})")
end
end
end
assert_flequal(0.0, Math.ldexp(0.0, 20))
assert_flequal(20.0, Math.ldexp(20.0, 0))
assert_flequal(41.0, Math.ldexp(20.5, 1))
assert_flequal(1259.52, Math.ldexp(1.23, 10))
assert_flequal(0.25, Math.ldexp(1, -2))
res = [-2.35619449019234, -0.785398163397448,
2.35619449019234, 0.785398163397448 ]
for x in [ -0.5, 0.5]
for y in [-0.5, 0.5]
assert_flequal(res.shift, Math.atan2(x, y))
end
end
# and some special cases
assert_equal(-1, Math.log(0).infinite?)
assert_equal(-1, Math.log10(0).infinite?)
end
end
|
