sklearn.metrics.pairwise
.polynomial_kernel¶
- sklearn.metrics.pairwise.polynomial_kernel(X, Y=None, degree=3, gamma=None, coef0=1)[source]¶
Compute the polynomial kernel between X and Y.
\(K(X, Y) = (gamma <X, Y> + coef0)^degree\)
Read more in the User Guide.
- Parameters:
- Xndarray of shape (n_samples_X, n_features)
A feature array.
- Yndarray of shape (n_samples_Y, n_features), default=None
An optional second feature array. If
None
, usesY=X
.- degreeint, default=3
Kernel degree.
- gammafloat, default=None
Coefficient of the vector inner product. If None, defaults to 1.0 / n_features.
- coef0float, default=1
Constant offset added to scaled inner product.
- Returns:
- Gram matrixndarray of shape (n_samples_X, n_samples_Y)
The polynomial kernel.