The χ2 Hessian

The χ2 Hessian in vector notation is

2χ2(θ) = 2$\displaystyle \sum_{{i=1}}^{n}$$\displaystyle {\frac{{1}}{{\sigma_i^2}}}$$\displaystyle \left(\vphantom{\nabla \mathrm{R}_i(\theta) \cdot \nabla \mathrm{...
...T - (\mathrm{R}_i- \mathrm{R}_i(\theta)) \nabla^2 \mathrm{R}_i(\theta) }\right.$∇Ri(θ)⋅∇Ri(θ)T - (Ri - Ri(θ))∇2Ri(θ)$\displaystyle \left.\vphantom{\nabla \mathrm{R}_i(\theta) \cdot \nabla \mathrm{...
...T - (\mathrm{R}_i- \mathrm{R}_i(\theta)) \nabla^2 \mathrm{R}_i(\theta) }\right)$. (15.15)



The relax user manual (PDF), created 2016-10-28.