how can i solve matrix riccati differential equation?

to solve matrix Riccati differential i am using the piece of code from mathswork support, which is as follows

function dXdt = mRiccati(t, X, A, B, Q)

X = reshape(X, size(A)); %Convert from "n^2"-by-1 to "n"-by-"n"

dXdt = A.'*X + X*A - X*B*B.'*X + Q; %Determine derivative

dXdt = dXdt(:); %Convert from "n"-by-"n" to "n^2"-by-1

[T X] = ode45(@(t,X)mRiccati(t, X, A, B, Q), [0 10], X0)

this code works well with dimension of A = 2x2. but gives error in builtin RESHAPE function when i change dimension of A(i.e A = 3x3, B=3x1, Q=3x3)

[Torsten]

Please include the settings for X0,A,B and Q before the call to ode45.

Best wishes

Torsten.

[Ana Navarro]

Why the negative sign in the Riccati differential equation is being ignored? Shouldn't be dXdt= - A.'X - X*A + X*B*B.'*X - Q ?