In the created in the 90th the anisotropy-based control theory, the sequence of the Gaussian random vectors with zero mean and certain mean anisotropy level was accepted as input perturbations acting on a linear system. In this paper, the author considers the concept of mean anisotropy of the sequence with nonzero mean and anisotropic norm of the system with given input. The problems of anisotropy-based analysis in frequency domain and state-space representation are considered. The difference between classical formulas for computing mean anisotropy and anisotropic norm and new formulas is shown. The problem of controller design is researched.