phase portrait error when run

i have an error when run this script, how to fix it ?

Output argument "lnear" (and maybe others) not assigned during call to "lnear".

Error in Untitled4>@(t,y)lnear(t,y) (line 11)
[t y] = ode45(@(t, y) lnear(t, y), tspan,iv);

Error in odearguments (line 90)
f0 = feval(ode,t0,y0,args{:});   % ODE15I sets args{1} to yp0.

Error in ode45 (line 115)
  odearguments(FcnHandlesUsed, solver_name, ode, tspan, y0, options, varargin);

Error in Untitled4 (line 11)
[t y] = ode45(@(t, y) lnear(t, y), tspan,iv);
 

Function 'lnear' has already been declared within this scope.

Error in connector.internal.fevalMatlab

Error in connector.internal.fevalJSON

Answer 1

[Sulaymon Eshkabilov]

Here is the corrected code:

clc; clear
figure1=figure;
axes1=axes('Parent',figure1,'FontSize',13);
grid on;
box(axes1,'on');
hold(axes1,'all');
to = 0 ;
tf = 30;
tspan = to : 0.001 : tf ;
iv = [ 12.3 0.1 0 0.1 0.1 ] ;
iv2 = [ 12.3 0 0 0 0 ] ;
iv3 = [ 12.65 0 0 0.1 0.1 ] ;
iv4 = [ 12.65 0.1 0.1 0 0 ] ;
iv5 = [ 12.485594 0 0 0 0.12 ] ;
iv6 = [ 12.3 0.1 0 0.1 0 ] ;
iv7 = [ 12.4 0.05 0 0.05 0 ] ;
iv8 = [ 12.65 0.05 0 0.05 0.05 ] ;
iv9 = [ 12.6 0.05 0 0.05 0 ] ;
[t, y] = ode45(@lnear, tspan, iv.');
[t, x] = ode45(@(t, x) lnear(t, x), tspan, iv2.');
[t, z] = ode45(@(t, z) lnear(t, z), tspan, iv3.');
[t, n] = ode45(@(t, n) lnear(t, n), tspan, iv4.');
[t, w] = ode45(@(t, w) lnear(t, w), tspan, iv5.');
[t, v] = ode45(@(t, v) lnear(t, v), tspan, iv6.');
[t, s] = ode45(@(t, s) lnear(t, s), tspan, iv7.');
[t, p] = ode45(@(t, p) lnear(t, p), tspan, iv8.');
[t, c] = ode45(@(t, c) lnear(t, c), tspan, iv9.');
plot(y(:,1), y(:,5)), grid on
plot(x(:,1), x(:,5)), grid on
plot(z(:,1), z(:,5)), grid on
plot(n(:,1), n(:,5)), grid on
plot(w(:,1), w(:,5)), grid on
plot(v(:,1), v(:,5)), grid on
plot(s(:,1), s(:,5)), grid on
plot(p(:,1), p(:,5)), grid on
plot(c(:,1), c(:,5)), grid on
plot(12.485594+0*tspan,0+0*t,'k*','LineWidth',10)
xlabel('y_1'), ylabel('y_5')

function dydt = lnear(t,y)
e1 = 13;
g = 0.0125;
h = 0.284253;
f = 0.05 ;
q1 = 0;
k1 = 10;
d1 = 0.0412;
e2 = 0.0188;
j = 0.0082;
q2 = 0;
k2 = 10;
d2 = 0.0288;
b = 2;
d4 = 0.1152;
e3 = 0.166667;
a = 1.7 ;
q3 = 0;
k3 = 10;
d3 = 0.1152;
r = 0.5 ;
m= 1.02 ;
q4 = 0;
k4 = 10;
dydt = [e1 + (g*y(3)*y(1)/(h + y(3))) + (f*y(3)*y(1)) - (y(1)*(1 + ((q1/k1)*y(1)))) - (d1*y(1));
          e2*y(2) + (f*y(1)*y(3)) - (j*y(2)) - (y(2)*(1 + ((q2/k2)*y(2)))) - (d2*y(2));
  (b*e2*y(2)) - (d4*y(3));
 e3*y(4) + (j*y(2)) - (a*y(4)) - (y(4)*(1 + ((q3/k3)*y(4)))) - (d3*y(4));
 (r*y(5)*(1 - (m*y(5)))) + (a*y(4)) - y(5)*(1 + ((q4/k4)*y(5)));];
end