Аннотация:We study the Roberge-Weiss phase transition numerically. The phase transition is associatedwith the discontinuities in the quark-number density at specific values of imaginary quark chemicalpotential. We parameterize the quark number density ρ_q by the polynomial fit function to computethe canonical partition functions. We demonstrate that this approach provides a good frameworkfor analyzing lattice QCD data at finite density and a high temperature. We show numerically thatat high temperature, the Lee-Yang zeros lie on the negative real semi-axis provided that the high-quark-number contributions to the grand canonical partition function are taken into account. TheseLee-Yang zeros have nonzero linear density, which signals the Roberge-Weiss phase transition. Wedemonstrate that this density agrees with the quark number density discontinuity at the transitionline.