How to solve simultaneous ODE equations in matlab with if/else if?

Hello, I have a set of ODE and I am writing the matlab code to solve it but unfortunately I don't get the right result, i.e., it becomes very slow. Could you please tell me where I am making mistake? I even used ode23s, but still the problem exists.

Here is the ODE:

surface.

And here is my matlab code:

function [ x,y,z ] = lorenz_like( alpha, beta, gamma,theta,const, initV, T, eps )

%This function generates data from Lorenz-like system

if nargin<5

    error('MATLAB:lorenz:NotEnoughInputs','Not enough input arguments.');
end

if nargin<6

    eps = 0.000001;

    delta_t=0.01;

    T =0:delta_t:100;

    initV = [40 40 0];

end

options = odeset('RelTol',eps,'AbsTol',[eps eps eps/10]);

[T,X] = ode45(@(T,X) F(T, X, alpha, beta, gamma,theta,const), T, initV, options);

x = X(:,1);

y = X(:,2);

z = X(:,3);

return

end

function dx = F(T, X, alpha, beta, gamma,theta,const)

dx = zeros(3,1);

x_1p=-14;

x_2p=-12;

x_3p=0;

x_1o=0;

x_2o=0;

x_3o=5;

x_1n=14;

x_2n=12;

x_3n=0;

A=[-alpha alpha 0;

    beta-x_3p -1 -x_1p;

    x_2p x_1p -gamma];

A_x=[X(1)-x_1p;

    X(2)-x_2p

    X(3)-x_3p];

B=[-alpha alpha 0;

    beta-x_3o -1 -x_1o;

    x_2o x_1o -gamma ];

B_x=[X(1)-x_1o;

    X(2)-x_2o

    X(3)-x_3o];

C=[-alpha alpha 0;

    beta-x_3n -1 -x_1n;

    x_2n x_1n -gamma];

C_x=[X(1)-x_1n;

    X(2)-x_2n

    X(3)-x_3n];

condition= X(1)*tan(theta)+X(2);

if condition>const

    dx=A*A_x;

elseif -const<=condition && condition<=const

    dx=B*B_x;

else

    dx=C*C_x;

end

return

end

[Sara]

Can you provide the input data and the right result for comparison?

[MINA]

For the input data you would just need to call:

[ x,y,z ] = lorenz_like( 10, 9, 4,pi/2,4 );

And then if you plot x for example you need to get this figure(a) and if you plot(x,y) you need to get figure(b)

[MINA]

It is solved now. The code is right. The number that was given in paper was not correct. I changed the number and I got the same result. Thanks