We propose a simple projection and rescaling algorithm to solve the feasibility problem find x ∈ L ∩ Ω, where L and Ω are respectively a linear subspace and the interior of a symmetric cone in a finite-dimensional vector space V . This projection and rescaling algorithm is inspired by previous work on rescaled versions of the perceptron algorithm and by Chubanov's projectionbased method for linear feasibility problems. As in these predecessors, each main iteration of our algorithm contains two steps: a basic procedure and a rescaling step. When L ∩ Ω = ∅, the projection and rescaling algorithm finds a pointis attained when L ∩ Ω contains the center of the symmetric cone Ω.We describe several possible implementations for the basic procedure including a perceptron scheme and a smooth perceptron scheme. The perceptron scheme requires O(r 4 ) perceptron updates and the smooth perceptron scheme requires O(r 2 ) smooth perceptron updates, where r stands for the Jordan algebra rank of V .
IntroductionWe propose a simple algorithm based on projection and rescaling operations to solve the feasibility problem findwhere L and Ω are respectively a linear subspace and the interior of a symmetric cone in a finite-dimensional vector space V . Problem (1) is fundamental in optimization as it encompasses a large class of feasibility problems. For example, for A ∈ R m×n and b ∈ R m , the problem Ax = b, x > 0 can be formulated as (1) by taking L = {(x, t) ∈ R n+1 : Ax − tb = 0} and Ω = R n+1 ++ . For A ∈ R m×n , c ∈ R n , the problem A