Convex optimization linear programming. Many optimization problems can be reformulated as convex minimization problems. For example, the problem of "maximizing" a "concave function" formula_1 can be re-formulated equivalently as a problem of minimizing the convex function formula_2. An optimization problem, which aims to find a point formula_3 such that formula_4 for all formula_5 in some feasible set formula_6, is convex if and only if formula_6 and the objective function formula_1 satisfy the following two properties: Perhaps more conveniently, the convex problem can be phrased in the more shorthand general definition of optimization: finding some formula_19 such that for some feasible set formula_6
Anticrepuscular rays Anticrepuscular rays Anticrepuscular rays, or antisolar rays, are atmospheric optical phenomena similar to crepuscular rays, but appear opposite of the Sun in the sky. Anticrepuscular rays are nearly parallel, but appear to converge toward the antisolar point due to linear perspective. Anticrepuscular rays are most frequently visible around sunrise or sunset. Appearing to radiate from the Sun, crepuscular rays usually look much brighter than anticrepuscular rays. This is because the atmospheric light scattering making the crepuscular rays visible occurs at low angles to the horizon (see Mie theory). Although anticrepuscular rays appear to converge toward the antisolar point, the convergence