def value(self):
        """
        Covariance matrix.

        Returns
        -------
        K : ndarray
            s⋅XXᵀ.
        """
        X = self.X
        return self.scale * (X @ X.T)
def value(self):
        """
        Covariance matrix.

        Returns
        -------
        K : ndarray
            s⋅XXᵀ.
        """
        X = self.X
        return self.scale * (X @ X.T)
def value ( self ) : X = self . X return self . scale * ( X @ X . T )
Covariance matrix.

        Returns
        -------
        K : ndarray
            s⋅XXᵀ.
Covariance matrix .