LOGICAL FUNCTION SB02MR( REIG, IEIG ) C C SLICOT RELEASE 5.0. C C Copyright (c) 2002-2009 NICONET e.V. C C This program is free software: you can redistribute it and/or C modify it under the terms of the GNU General Public License as C published by the Free Software Foundation, either version 2 of C the License, or (at your option) any later version. C C This program is distributed in the hope that it will be useful, C but WITHOUT ANY WARRANTY; without even the implied warranty of C MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the C GNU General Public License for more details. C C You should have received a copy of the GNU General Public License C along with this program. If not, see C . C C PURPOSE C C To select the unstable eigenvalues for solving the continuous-time C algebraic Riccati equation. C C ARGUMENTS C C Input/Output Parameters C C REIG (input) DOUBLE PRECISION C The real part of the current eigenvalue considered. C C IEIG (input) DOUBLE PRECISION C The imaginary part of the current eigenvalue considered. C C METHOD C C The function value SB02MR is set to .TRUE. for an unstable C eigenvalue and to .FALSE., otherwise. C C REFERENCES C C None. C C NUMERICAL ASPECTS C C None. C C CONTRIBUTOR C C V. Sima, Katholieke Univ. Leuven, Belgium, Aug. 1997. C C REVISIONS C C - C C KEYWORDS C C Algebraic Riccati equation, closed loop system, continuous-time C system, optimal regulator, Schur form. C C ****************************************************************** C C .. Parameters .. DOUBLE PRECISION ZERO PARAMETER ( ZERO = 0.0D0 ) C .. Scalar Arguments .. DOUBLE PRECISION IEIG, REIG C .. Executable Statements .. C SB02MR = REIG.GE.ZERO C RETURN C *** Last line of SB02MR *** END