# How do I get this graph?

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Joo Seo Lee on 25 Apr 2020
Commented: Ameer Hamza on 25 Apr 2020
I want to get the graph of n and x(n) on x(n+1)=2.5*x(n)*(1-x(n)), where x(1)=0.9
I wrote
x(1)=0.9;
for n = 1:100,
x(n+1)=x(n)*(1-x(n))*2.5
plot (x(n),n)
end
and my plot is empty

Ameer Hamza on 25 Apr 2020
Edited: Ameer Hamza on 25 Apr 2020
Try this
x(1)=0.9;
for n = 1:100
x(n+1)=x(n)*(1-x(n))*2.5;
end
plot(x)
In your code, you are just plotting one point at a time and then overwriting it with a new plot statement.

Joo Seo Lee on 25 Apr 2020
thanks!
Ameer Hamza on 25 Apr 2020

Sriram Tadavarty on 25 Apr 2020
Hi Joo,
The code is calculating as you expected, but not plotting the same because, the plot is getting overwritten with the latest value of x(n).
You can try the following code modifications:
Option 1:
Use hold on to update the figure for each iteration
x(1)=0.9;
for n = 1:100
x(n+1)=x(n)*(1-x(n))*2.5;
plot(n,x(n),'*') % Plotting at each point, line doesn't help, so try symbols
hold on
end
Option 2:
Plot x after the computation
x(1)=0.9;
for n = 1:100
x(n+1)=x(n)*(1-x(n))*2.5;
end
plot(x)
Hope this helps.
Regards,
Sriram