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mvpa2.kernels.np.RationalQuadraticKernel

class mvpa2.kernels.np.RationalQuadraticKernel(length_scale=1.0, sigma_f=1.0, alpha=0.5, **kwargs)

The Rational Quadratic (RQ) kernel class.

Note that it can handle a length scale for each dimension for Automtic Relevance Determination.

Initialize a Squared Exponential kernel instance.

Parameters :

length_scale : float or numpy.ndarray

the characteristic length-scale (or length-scales) of the phenomenon under investigation. (Defaults to 1.0)

sigma_f : float

Signal standard deviation. (Defaults to 1.0)

alpha : float

The parameter of the RQ functions family. (Defaults to 2.0)

enable_ca : None or list of str

Names of the conditional attributes which should be enabled in addition to the default ones

disable_ca : None or list of str

Names of the conditional attributes which should be disabled

gradient(data1, data2)

Compute gradient of the kernel matrix. A must for fast model selection with high-dimensional data.

set_hyperparameters(hyperparameter)

Set hyperaparmeters from a vector.

Used by model selection. Note: ‘alpha’ is not considered as an hyperparameter.