Function ref_rbf_kernel

tests/gpflow/kernels/reference.py:17–31

(
    X: AnyNDArray, lengthscales: AnyNDArray, signal_variance: AnyNDArray
)

    "signal_variance: [broadcast D_tuple...]",
)
def ref_rbf_kernel(
    X: AnyNDArray, lengthscales: AnyNDArray, signal_variance: AnyNDArray
) -> AnyNDArray:
    N, _ = X.shape
    kernel = np.zeros((N, N))
    for row_index in range(N):
        for column_index in range(N):
            vecA = X[row_index, :]
            vecB = X[column_index, :]
            delta = vecA - vecB
            distance_squared = np.dot(delta.T, delta)
            kernel[row_index, column_index] = signal_variance * np.exp(
                -0.5 * distance_squared / lengthscales ** 2
            )
    return kernel


@check_shapes(