def test_kernel_ridge_multi_output():
pred = Ridge(alpha=1, fit_intercept=False).fit(X, Y).predict(X)
pred2 = KernelRidge(kernel="linear", alpha=1).fit(X, Y).predict(X)
assert_array_almost_equal(pred, pred2)
pred3 = KernelRidge(kernel="linear", alpha=1).fit(X, y).predict(X)
pred3 = np.array([pred3, pred3]).T
assert_array_almost_equal(pred2, pred3)
def test_kernel_ridge_singular_kernel():
# alpha=0 causes a LinAlgError in computing the dual coefficients,
# which causes a fallback to a lstsq solver. This is tested here.
pred = Ridge(alpha=0, fit_intercept=False).fit(X, y).predict(X)
kr = KernelRidge(kernel="linear", alpha=0)
ignore_warnings(kr.fit)(X, y)
pred2 = kr.predict(X)
assert_array_almost_equal(pred, pred2)
def test_kernel_ridge_sample_weights():
K = np.dot(X, X.T) # precomputed kernel
sw = np.random.RandomState(0).rand(X.shape[0])
pred = Ridge(alpha=1, fit_intercept=False).fit(X, y,
sample_weight=sw).predict(X)
pred2 = KernelRidge(kernel="linear",
alpha=1).fit(X, y, sample_weight=sw).predict(X)
pred3 = KernelRidge(kernel="precomputed",
alpha=1).fit(K, y, sample_weight=sw).predict(K)
assert_array_almost_equal(pred, pred2)
assert_array_almost_equal(pred, pred3)
# Add noise to targets
y[::5] += 3 * (0.5 - rng.rand(X.shape[0] // 5))
X_plot = np.linspace(0, 5, 100000)[:, None]
# #############################################################################
# Fit regression model
train_size = 100
svr = GridSearchCV(SVR(kernel='rbf', gamma=0.1),
param_grid={
"C": [1e0, 1e1, 1e2, 1e3],
"gamma": np.logspace(-2, 2, 5)
})
kr = GridSearchCV(KernelRidge(kernel='rbf', gamma=0.1),
param_grid={
"alpha": [1e0, 0.1, 1e-2, 1e-3],
"gamma": np.logspace(-2, 2, 5)
})
t0 = time.time()
svr.fit(X[:train_size], y[:train_size])
svr_fit = time.time() - t0
print("SVR complexity and bandwidth selected and model fitted in %.3f s" %
svr_fit)
t0 = time.time()
kr.fit(X[:train_size], y[:train_size])
kr_fit = time.time() - t0
print("KRR complexity and bandwidth selected and model fitted in %.3f s" %
def test_kernel_ridge_precomputed_kernel_unchanged():
K = np.dot(X, X.T)
K2 = K.copy()
KernelRidge(kernel="precomputed").fit(K, y)
assert_array_almost_equal(K, K2)
def test_kernel_ridge_precomputed():
for kernel in ["linear", "rbf", "poly", "cosine"]:
K = pairwise_kernels(X, X, metric=kernel)
pred = KernelRidge(kernel=kernel).fit(X, y).predict(X)
pred2 = KernelRidge(kernel="precomputed").fit(K, y).predict(K)
assert_array_almost_equal(pred, pred2)
def test_kernel_ridge_csc():
pred = Ridge(alpha=1, fit_intercept=False,
solver="cholesky").fit(Xcsc, y).predict(Xcsc)
pred2 = KernelRidge(kernel="linear", alpha=1).fit(Xcsc, y).predict(Xcsc)
assert_array_almost_equal(pred, pred2)
def test_kernel_ridge():
pred = Ridge(alpha=1, fit_intercept=False).fit(X, y).predict(X)
pred2 = KernelRidge(kernel="linear", alpha=1).fit(X, y).predict(X)
assert_array_almost_equal(pred, pred2)
from mrex.gaussian_process import GaussianProcessRegressor
from mrex.gaussian_process.kernels import WhiteKernel, ExpSineSquared
rng = np.random.RandomState(0)
# Generate sample data
X = 15 * rng.rand(100, 1)
y = np.sin(X).ravel()
y += 3 * (0.5 - rng.rand(X.shape[0])) # add noise
# Fit KernelRidge with parameter selection based on 5-fold cross validation
param_grid = {"alpha": [1e0, 1e-1, 1e-2, 1e-3],
"kernel": [ExpSineSquared(l, p)
for l in np.logspace(-2, 2, 10)
for p in np.logspace(0, 2, 10)]}
kr = GridSearchCV(KernelRidge(), param_grid=param_grid)
stime = time.time()
kr.fit(X, y)
print("Time for KRR fitting: %.3f" % (time.time() - stime))
gp_kernel = ExpSineSquared(1.0, 5.0, periodicity_bounds=(1e-2, 1e1)) \
+ WhiteKernel(1e-1)
gpr = GaussianProcessRegressor(kernel=gp_kernel)
stime = time.time()
gpr.fit(X, y)
print("Time for GPR fitting: %.3f" % (time.time() - stime))
# Predict using kernel ridge
X_plot = np.linspace(0, 20, 10000)[:, None]
stime = time.time()
y_kr = kr.predict(X_plot)