MATLAB: How to plot x(n) for many values of n

MATLABn values of x

How to plot ?(?) = ?? ?(0) for n=1-30 and x(0)=100?? I have tried this code, but it is repeating it's value again and again… What I am missing?

alpha = 2
x0 = 100; % Initial conditions  
for n = 1:30
    x(n) = (alpha^n)*(x0)
end
disp(x(n))

Best Answer

Shorter code eliminating loop:

Alpha = 2
x0 = 100; % Initial conditions  
n = 1:30;
x = Alpha.^n*x0;
plot(n,x)

Note: You were doing it correctly all you had to use was disp(x)

Related Solutions

MATLAB: How can we find the doubling time of a curve

There is a formula for doubling time, if (n1,x1) and (n2,x2) are two data points selected, then doubling time Td is given by:

In your case: Follow the below:

Alpha = [1.05 ];  % Initial conditions 

x0 = 100; % Initial conditions 
figure 
n = 1:30;
x = Alpha.^n*x0;
plot(n,log2(x));
title('Figure 1A-Alpha=1.05'),xlabel('X-Axis','fontweight','bold'), ylabel('Y-Axis','fontweight','bold') 
% pick any two quantities randomly 
idx = [5 15]; 
x1 = x(idx(1)) ; x2 = x(idx(2)) ;
n1 = n(idx(1)) ; n2 = n(idx(2)) ; 
% doubling time 
Td = (n2-n1)*log(2)/log(x2/x1)

The doubling time is found to be 14.207. Change the values of (n1,q1) and (n2,q2) you will get the same value for the data picked.

MATLAB: I’m trying to plot this for loop with the kappa values with respect to the increasing n but the plot that it shows is empty and the x axis is from 99 to 101 instead of 1 to 100 like the for loop dictates. Can anybody tell me what I’m doing wrong

Try this slight variation on your code:

for n=1:100
    lammax(n) = 4-2*cos(sqrt(n)*pi/(sqrt(n)+1));
    lammin(n) = 4-2*cos(pi/(sqrt(n)+1));
    kappa(n) = lammax(n)/lammin(n);
end
n=1:100;
plot(n, kappa, 'r--')
xlabel('n')
ylabel('Condition Number')

Best Answer

Related Solutions

MATLAB: How can we find the doubling time of a curve

MATLAB: I’m trying to plot this for loop with the kappa values with respect to the increasing n but the plot that it shows is empty and the x axis is from 99 to 101 instead of 1 to 100 like the for loop dictates. Can anybody tell me what I’m doing wrong

Related Question