xMean

Mean added back to zero-order spline evaluations.

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Type

• Class: double
• Size: (1,1)

Description

Real valued property with no dimensions and no units.

Discussion

xMean is an output offset used in the stored spline model

\[f(t) = x_{\mathrm{Mean}} + x_{\mathrm{Std}} \sum_{j=1}^{M} \xi_j B_{j,S}(t;\tau).\]

This affine output normalization is useful for numerical work: large means can be removed before solving for the coefficient vector, then added back only at evaluation time. That keeps the fitted coefficients closer to order one and reduces the need to represent a large constant level directly in xi.

xMean contributes only to zero-order evaluation. Derivatives are unaffected because constants differentiate to zero.

  spline = BSpline(S=3, knotPoints=knotPoints, xi=xi, xMean=12.4, xStd=0.8);
  values = spline(tQuery);