bladex.ndinterpolator.RBF.beckert_wendland_c2_basis¶

static RBF.beckert_wendland_c2_basis(X, r)[source]¶

It implements the following formula:

$\varphi(\| \boldsymbol{x} \|) = \left( 1 - \frac{\| \boldsymbol{x} \|}{r} \right)^4 + \left( 4 \frac{\| \boldsymbol{x} \|}{r} + 1 \right)$

Parameters:	X (numpy.ndarray) – l2-norm between given inputs of a function and the locations to perform rbf approximation to that function. r (float) – smoothing length, also called the cut-off radius.
Returns:	result: the result of the formula above.
Return type:	float