why is it not plotting?? blank graph

% Ecuaciones Diferenciales Ordinarias dy/dx=f(x,y) a resolver --------------  
f1 =@(x,y1,y2) (-6*y2-5*y1)/.5

f1 = function_handle with value:
    @(x,y1,y2)(-6*y2-5*y1)/.5

f2 =@(x,y1,y2) (-.5*y1-5)/6

f2 = function_handle with value:
    @(x,y1,y2)(-.5*y1-5)/6

% Condiciones iniciales -----------------------------------------------
%y1(0)=1;
%y2(0)=0;

x=0

x = 0

xn=5

xn = 5

y1=1

y1 = 1

y2=0

y2 = 0

h=0.2

h = 0.2000

% Método de RK4Orden ---------------------------------------------------
while x(end)<=xn
    k11= f1(x(end),y1(end),y2(end)); 
    k12= f2(x(end),y1(end),y2(end)); 
    k21= f1(x(end)+.5*h,y1(end)+.5*k11*h,y2(end)+.5*k12*h);
    k22= f2(x(end)+.5*h,y1(end)+.5*h*k11,y2(end)+.5*h*k12);
    k31= f1(x(end)+.5*h,y1(end)+.5*k21*h,y2(end)+.5*k22*h);
    k32= f2(x(end)+.5*h,y2(end)+.5*k22*h,y2(end)+.5*k22*h);
    k41= f1(x(end)+h,y1(end)+k31*h,y2(end)+k32*h);
    k42= f2(x(end)+h,y2(end)+k32*h,y2(end)+k32*h);
    x(end+1)=x(end)+h;
    %y1(end+1)=y1(end)+1/6*(k11+2*k21+2*k31+k41)*h;    
    %y2(end+1)=y2(end)+1/6*(k12+2*k22+2*k32+k42)*h;   
end

% Graficación de la solución ------------------------------------------

plot(x,y1)
title('Carga respecto al tiempo')
xlabel('tiempo')
ylabel('carga')
hold on
plot(x,y2)
xlabel('tiempo')
ylabel('corriente')
title('Corriente respecto al tiempo')

Answer 1

[MJFcoNaN]

Why do you comment the lines of calculate y1 and y2?

% Ecuaciones Diferenciales Ordinarias dy/dx=f(x,y) a resolver --------------  
f1 =@(x,y1,y2) (-6*y2-5*y1)/.5;
f2 =@(x,y1,y2) (-.5*y1-5)/6;
% Condiciones iniciales -----------------------------------------------
%y1(0)=1;
%y2(0)=0;
x=0;
xn=5;
y1=1;
y2=0;
h=0.2;
% Método de RK4Orden ---------------------------------------------------
while x(end)<=xn
    k11= f1(x(end),y1(end),y2(end)); 
    k12= f2(x(end),y1(end),y2(end)); 
    k21= f1(x(end)+.5*h,y1(end)+.5*k11*h,y2(end)+.5*k12*h);
    k22= f2(x(end)+.5*h,y1(end)+.5*h*k11,y2(end)+.5*h*k12);
    k31= f1(x(end)+.5*h,y1(end)+.5*k21*h,y2(end)+.5*k22*h);
    k32= f2(x(end)+.5*h,y2(end)+.5*k22*h,y2(end)+.5*k22*h);
    k41= f1(x(end)+h,y1(end)+k31*h,y2(end)+k32*h);
    k42= f2(x(end)+h,y2(end)+k32*h,y2(end)+k32*h);
    x(end+1)=x(end)+h;
    % these two lines update y1 and y2
    y1(end+1)=y1(end)+1/6*(k11+2*k21+2*k31+k41)*h;    
    y2(end+1)=y2(end)+1/6*(k12+2*k22+2*k32+k42)*h;   
end
% Graficación de la solución ------------------------------------------
plot(x,y1)
title('Carga respecto al tiempo')
xlabel('tiempo')
ylabel('carga')
hold on
plot(x,y2)
xlabel('tiempo')
ylabel('corriente')
title('Corriente respecto al tiempo')