xStd

Multiplicative scale applied to evaluations.

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Type

• Class: double
• Size: (1,1)

Description

Real valued property with no dimensions and no units.

Discussion

xStd is the multiplicative scale factor in

\[f(x_1,\ldots,x_d) = x_{\mathrm{Mean}} + x_{\mathrm{Std}} \sum_{j_1,\ldots,j_d} \xi_{j_1,\ldots,j_d} \prod_{k=1}^{d} B_{j_k,S_k}(x_k;\tau_k).\]

It is useful when the fitted field has large or very small amplitude: the stored coefficient array can remain close to order one while evaluations and derivatives are rescaled back to physical units.