plot variable values of loop

Hello

I have a code like this

for k=1:3
    %something
    
    if %one condition
        d=d-2
    if %the other condition
        d=d+3
    end
    end   
end

Basically I've written a loop in which I change the value of d

I have 3 iterations and 3 values of d.

I want to plot the values of d against the iteration's number, so that the x axis will be the iteration numbers and the y axis will be the values of d. How can I do this?

I've searched similar questions but haven't found like this one.

Thank you

[Tommy]

Possibly it will work to save the values of d?

d = zeros(4,1);
d(1) = 0; % put initial value for d here
for k=1:3
    %something
    
    if %one condition
        d(k+1)=d(k)-2
    elseif %the other condition
        d(k+1)=d(k)+3
    end   
end
plot(1:3,d(2:end))

[Ani Asoyan]

That is great, but it gives me errors. I have an .m file like this

%something......
d=zeros(p+1,1)
d(1)=0.2
p=3
for k=1:p
    %parameterized function 
     a=2; b=2; c=0.5; e=0.5;
    u_g = @(x, x_e, N)(-0.5*a*x.^2+b*(x-x_e)-c*N+e*u_p(x,x_e,N, d(k)));
    
    %something......
    p=(u_p(Z(:,1), Z(:,3), Z(:,2),d(k)).');
    
     if %one condition
        d(k+1)=d(k)-2
    elseif %the other condition
        d(k+1)=d(k)+3
    end   
end
plot(1:p,d(2:end))

and I have one function file

function u=u_p(x,x_e,N,d)

u = -(x-x_e).^2+N.*d(k);
end

can I change the value of d in function file or in the loop? I want to change it in every iteration and then make my calculations based on d's new value. but there are some errors like this

Undefined function or variable 'k'.

Error in u_p (line 3)
u = -(x-x_e).^2+N.*d(k);

Error in game>@(x,x_e,N)(-0.5*a*x.^2+b*(x-x_e)-c*N+e*u_p(x,x_e,N,d(k)))

Error in game (line 36)
g=(u_g(Z(:,1),Z(:,3), Z(:,2) ).');

>> 

[Rik]

Since you are providing only one value of d to your subfunction you don't need to index it again.

[Ani Asoyan]

so should I delete all the indexes or only the index in the function? that doesn't work either way

[Rik]

If you indeed call your function with this

p=u_p(Z(:,1), Z(:,3), Z(:,2),d(k)).';

then your function should look like this

function u=u_p(x,x_e,N,d)
u = -(x-x_e).^2+N.*d;
end

[Ani Asoyan]

I got it ! Thank you sooo much!!