3 papers
math.ST2026
A Scale Invariance Property of PCA
Jonathan Landy
The PCA algorithm is sensitive to changes in measurement scale. Measuring one variable of a system in inches rather than centimeters, say, alters both its principal axes and princi…
cs.LG2017
Stepwise regression for unsupervised learning
Jonathan Landy
I consider unsupervised extensions of the fast stepwise linear regression algorithm \cite{efroymson1960multiple}. These extensions allow one to efficiently identify highly-represen…
physics.chem-ph2008
Fourier expansions for the potentials of lattices of charge
Jonathan Landy
We apply the Poisson sum rule to obtain formal expressions for the Fourier coefficients of the potential of a lattice of generalized charge. Each generalized charge is assumed to c…