riccati — Riccati equation
X=riccati(A,B,C,dom,[typ]) [X1,X2]=riccati(A,B,C,dom,[typ])
real matrices nxn, B and C symetric.
: 'c' or 'd' for the time domain (continuous or discrete)
string : 'eigen' for block diagonalization or schur' for Schur method.
square real matrices (X2 invertible), X symmetric