pdim
New Bounds for Hyperparameter Tuning of Regression Problems Across Instances
The task of tuning regularization coefficients in regularized regression models with provable guarantees across problem instances still poses a significant challenge in the literature. This paper investigates the sample complexity of tuning regularization parameters in linear and logistic regressions under ℓ1 and ℓ2-constraints in the data-driven setting. For the linear regression problem, by more carefully exploiting the structure of the dual function class, we provide a new upper bound for the pseudo-dimension of the validation loss function class, which significantly improves the best-known results on the problem. Remarkably, we also instantiate the first matching lower bound, proving our results are tight. For tuning the regularization parameters of logistic regression, we introduce a new approach to studying the learning guarantee via an approximation of the validation loss function class. We examine the pseudo-dimension of the approximation class and construct a uniform error bound between the validation loss function class and its approximation, which allows us to instantiate the first learning guarantee for the problem of tuning logistic regression regularization coefficients.
Sample Complexity of Learning Heuristic Functions for Greedy-Best-First and A* Search
Greedy best-first search (GBFS) and A* search (A*) are popular algorithms for pathfinding on large graphs. Both use so-called heuristic functions, which estimate how close a vertex is to the goal. While heuristic functions have been handcrafted using domain knowledge, recent studies demonstrate that learning heuristic functions from data is effective in many applications. Motivated by this emerging approach, we study the sample complexity of learning heuristic functions for GBFS and A*. We build on a recent framework called data-driven algorithm design and evaluate the pseudo-dimension of a class of utility functions that measure the performance of parameterized algorithms.
Sobolev_VC
This allows us to bound each term in the sum using Lemma 1. Therefore, we conclude that 64 C ˆ C . For the last equation Eq. (27) is due to The proof of the first inequality Eq. (30) can be found in [ Eq. (31) can be obtained via induction. We prove this lemma via induction. Hence we finish our proof.