cherab.phix.inversion._SVDBase.w

_SVDBase.w(beta)Source

Calculate window function using regularization parameter \(\lambda\).

The window function is defined as follows:

\[w(\lambda) \equiv \frac{1}{1 + \lambda / \sigma^2},\]

where \(\sigma\) is the singular value of \(A\). Because \(\sigma\) is a vector, the window function is also a vector.

Parameters:

beta (float) – regularization parameter

Returns:

vector of window function

Return type:

numpy.ndarray (N, )