Comments on "Solutions to the combined sensitivity and complementary sensitivity problem in control systems
M. Zeren, Hitay Özbay · IEEE Transactions on Automatic Control · 1998
In the above-mentioned paper by Lim et al. (1996) a numerical example is given to show that the Nevanlinna-Pick interpolation formulas appearing in Khargonekar and Tannenbaum (1985) and Krein and Nudel'man (1977) are incorrect. By comparing the paper of Krein and Nudel'man with Adamjan (1971) we illustrate that the correct formulas are obtained by simply taking the transpose of the Pick matrix given in the first two above mentioned papers.