In this pa[er, we give a faSt algorithm to compute inverse of r-circulan matrixand symmetric r-circulat matris, when circulaat matrir is nonsingular; to computethe group inverse of r-circulant matris, when r-circulant marix singufor; to computethe {1, 2} inverse of symmetric r-circulant matris, when symmetric r-circulant matrix singular.
