gklearn.utils.kernels

Those who are not graph kernels. We can be kernels for nodes or edges! These kernels are defined between pairs of vectors.

chi2_kernel(x, y, gamma=1.0)[source]
cosine_kernel(x, y)[source]
delta_kernel(x, y)[source]
deltakernel(x, y)[source]
exponential_kernel(x, y, gamma=None)[source]
gaussian_kernel(x, y, gamma=None)[source]

Gaussian kernel. Compute the rbf (gaussian) kernel between x and y:

K(x, y) = exp(-gamma ||x-y||^2).

Read more in the User Guide of scikit-learn library.

Parameters

x, y : array

gammafloat, default None

If None, defaults to 1.0 / n_features

Returns

kernel : float

gaussiankernel(x, y, gamma=None)[source]
highest_polynomial_kernel(x, y, d=1, c=0)[source]

Polynomial kernel. Compute the polynomial kernel between x and y:

K(x, y) = <x, y> ^d + c.

Parameters

x, y : array

d : integer, default 1

c : float, default 0

Returns

kernel : float

intersection_kernel(x, y)[source]
inverse_multiquadratic_kernel(x, y, c=0)[source]
kernelproduct(k1, k2, d11, d12, d21=None, d22=None, lamda=1)[source]

Product of a pair of kernels.

k = lamda * k1(d11, d12) * k2(d21, d22)

Parameters

k1, k2function

A pair of kernel functions.

d11, d12:

Inputs of k1. If d21 or d22 is None, apply d11, d12 to both k1 and k2.

d21, d22:

Inputs of k2.

lamda: float

Coefficient of the product.

Return

kernel : integer

kernelsum(k1, k2, d11, d12, d21=None, d22=None, lamda1=1, lamda2=1)[source]

Sum of a pair of kernels.

k = lamda1 * k1(d11, d12) + lamda2 * k2(d21, d22)

Parameters

k1, k2function

A pair of kernel functions.

d11, d12:

Inputs of k1. If d21 or d22 is None, apply d11, d12 to both k1 and k2.

d21, d22:

Inputs of k2.

lamda1, lamda2: float

Coefficients of the product.

Return

kernel : integer

kronecker_delta_kernel(x, y)[source]

Delta kernel. Return 1 if x == y, 0 otherwise.

Parameters

x, yany

Two parts to compare.

Return

kernelinteger

Delta kernel.

References

[1] H. Kashima, K. Tsuda, and A. Inokuchi. Marginalized kernels between labeled graphs. In Proceedings of the 20th International Conference on Machine Learning, Washington, DC, United States, 2003.

laplacian_kernel(x, y, gamma=None)[source]
linear_kernel(x, y)[source]

Polynomial kernel. Compute the polynomial kernel between x and y:

K(x, y) = <x, y>.

Parameters

x, y : array

d : integer, default 1

c : float, default 0

Returns

kernel : float

linearkernel(x, y)[source]
multiquadratic_kernel(x, y, c=0)[source]
polynomial_kernel(x, y, gamma=1, coef0=0, d=1)[source]
polynomialkernel(x, y, d=1, c=0)[source]
sigmoid_kernel(x, y, gamma=None, coef0=1)[source]
tanimoto_kernel(x, y)[source]