def test_pca_variance():
samples = [PointCloud(np.random.randn(10)) for _ in range(10)]
model = PCAModel(samples)
# kept variance must be equal to total variance
assert_equal(model.variance(), model.original_variance())
# kept variance ratio must be 1.0
assert_equal(model.variance_ratio(), 1.0)
# noise variance must be 0.0
assert_equal(model.noise_variance(), 0.0)
# noise variance ratio must be also 0.0
assert_equal(model.noise_variance_ratio(), 0.0)
def test_pca_variance():
samples = [PointCloud(np.random.randn(10)) for _ in range(10)]
model = PCAModel(samples)
# kept variance must be equal to total variance
assert_equal(model.variance(), model.original_variance())
# kept variance ratio must be 1.0
assert_equal(model.variance_ratio(), 1.0)
# noise variance must be 0.0
assert_equal(model.noise_variance(), 0.0)
# noise variance ratio must be also 0.0
assert_equal(model.noise_variance_ratio(), 0.0)
def test_pca_variance_after_trim():
samples = [PointCloud(np.random.randn(10)) for _ in range(10)]
model = PCAModel(samples)
# set number of active components
model.trim_components(5)
# kept variance must be smaller than total variance
assert(model.variance() < model.original_variance())
# kept variance ratio must be smaller than 1.0
assert(model.variance_ratio() < 1.0)
# noise variance must be bigger than 0.0
assert(model.noise_variance() > 0.0)
# noise variance ratio must also be bigger than 0.0
assert(model.noise_variance_ratio() > 0.0)
# inverse noise variance is computable
assert(model.inverse_noise_variance() == 1 / model.noise_variance())
