
Quantum State
December 22, 2019
This is a very short primer on quantum mechanics, and the bare minimum that needs to be explained in order to understand what QM is about. My goal is to provide some conceptual punchlines with minimal prereqs. The formalism of QM is filled with technicalities and complications, which I try to point out where possible. Keep in mind I am glossing over a ton of details. The focus of this post is to introduce two equivalent views on quantum state is: Quantum states are $L^2$normalized complexvalued functions over classical configuration space. Quantum states are unit vectors residing in a complex Hilbert space, $\mathcal{H}$. …

BiasVariance Decomposition
July 14, 2019
All about the biasvariance decomposition as it pertains to machine learning. All you need to know: $$ \begin{align*} & \mathbb{E}_D[(f(x; D)  y(x))^2] \qquad\quad\ \textrm{Avg. error}\\ & = (\mathbb{E}_D[f(x; D)]  y(x))^2 \qquad \textrm{Bias}_y(f)^2\\ &\phantom{=}\, + \mathbb{V}_D[f(x; D)] \qquad\qquad\quad\ \, \textrm{Variance}(f)\\ \end{align*} $$ …