## What's wrong with this code?

### Sam (view profile)

on 21 Mar 2014
Latest activity Commented on by Star Strider

### Star Strider (view profile)

on 21 Mar 2014

I am getting this error msg. Please find me the mistakes here.

In an assignment A(I) = B, the number of elements in B and I must be the same.

r=[2.0 3.1 3.5 3.65 3.84 3.95];

x=[];

x(1)=0.35;

f=@(x) r*x*(1-x);

N=40;

for t=1:N-1;

x(t+1)=f(x(t));

end

hold on

plot(x,'r-')

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### Joseph Cheng (view profile)

on 21 Mar 2014

yes thats because you are including information that is not here and in your other posting that was flagged. but looks like you have it so we're all set?

Sam

### Sam (view profile)

on 21 Mar 2014

Sorry I can't use that. My friend just sent me to see what he did. So, if I use that, I will be cheating. That's why I am exhausting myself here. But, thanks for all your help. Atleast, you're not making any rude comments.

Joseph Cheng

### Joseph Cheng (view profile)

on 21 Mar 2014

only rude comment from me would be that posting on a forum for assignment questions involving things besides what type of functions to use, function errors, random matlab issues, and approaches to handling data is cheating. The Teaching Assistant or office hours should be where assignment related questions be asked.

Star Strider

### Star Strider (view profile)

on 21 Mar 2014

And it’s not cheating to have MATLAB Answers do your homework for you?

### Joseph Cheng (view profile)

on 21 Mar 2014
Edited by Joseph Cheng

### Joseph Cheng (view profile)

on 21 Mar 2014

Were you attempting to do this?

```r=[2.0 3.1 3.5 3.65 3.84 3.95];
x=[];
x(1,:)=0.35*ones(size(r));
f=@(x) r*x*(1-x);
N=40;
for t=1:N-1;
x(t+1,:)=f(x(t));
end
hold on
plot(x)
legend('r = 2.0','r = 3.1', 'r = 3.65')
```

Where the first value of x is 0.35? or you can re-write it such that the function

```f=@(x,r) r*x*(1-x);
```

such that you write a for loop to cycle in the r you need.

Joseph Cheng

### Joseph Cheng (view profile)

on 21 Mar 2014

and for the information given so far i've shown you how to get each f(x) as a function of x for each of the r's. and we've explained the error.

Sam

### Sam (view profile)

on 21 Mar 2014

Yes, but the graph I am getting for each individual r is completely different from when I use all the r values together if that make any sense to you.

Joseph Cheng

### Joseph Cheng (view profile)

on 21 Mar 2014

no it doesn't make sense. how do they look different? shape? amplitude?