code2

class pyhf.interpolators.code2(histogramssets, subscribe=True)

Bases: object

The quadratic interpolation and linear extrapolation strategy.

\[\sigma_{sb} (\vec{\alpha}) = \sigma_{sb}^0(\vec{\alpha}) + \underbrace{\sum_{p \in \text{Syst}} I_\text{quad.|lin.} (\alpha_p; \sigma_{sb}^0, \sigma_{psb}^+, \sigma_{psb}^-)}_\text{deltas to calculate}\]

with

\[\begin{split}I_\text{quad.|lin.}(\alpha; I^0, I^+, I^-) = \begin{cases} (b + 2a)(\alpha - 1) \qquad \alpha \geq 1\\ a\alpha^2 + b\alpha \qquad |\alpha| < 1 \\ (b - 2a)(\alpha + 1) \qquad \alpha < -1 \end{cases}\end{split}\]

and

\[a = \frac{1}{2} (I^+ + I^-) - I^0 \qquad \mathrm{and} \qquad b = \frac{1}{2}(I^+ - I^-)\]

__init__(histogramssets, subscribe=True)

Quadratic Interpolation.

Methods

_precompute()

_precompute_alphasets(alphasets_shape)