The Goodman line connects formula 5 on the abscissa and formula 4 on the ordinate. The abscissa is in units of time and the ordinate is usually in decibels. The abscissa of convergence of a Dirichlet series can be defined as formula 13 above. In general, the abscissa of convergence does not coincide with abscissa of absolute convergence. The abscissa of convergence of formula 28 is defined as formula 29. The proof is implicit in the definition of abscissa of convergence. Dependent upon the abscissa metrics chosen, Fig.