How can i make a n-pointed star?

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clear all; close all; clc;

N = input('natural number 1~100 : ');

m = ceil(sqrt(length(N))); 
n = ceil(sqrt(length(N)));

figure('number','off'); hold on
  for c = 1 : length(N) ;

        if rem(N(1,c),2)==1       %odd number
        t = 0:N:N(1,c)*N(1,c); 
        x = cos((N(1,c)-1)/N(1,c)*pi*t);
        y = sin((N(1,c)-1)/N(1,c)*pi*t);        

        else           %even number(Now, even number code = odd number code)
        t = 0:N.*N:N(1,c)*N(1,c); 
        x = cos((N(1,c)-1)/N(1,c)*pi*t);
        y = sin((N(1,c)-1)/N(1,c)*pi*t);  
        end

        subplot(m,n,c); hold on
        plot(x,y)
        hold off   
    end
hold off

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I'm student of korea ,which learning MATLAB

I input vector 1:9, this figure out.

if I input odd number, maked n-pointed star. but I input even number, maked 2n-pointed star.

How can I n-pointed star???? please

Answer 1

[Giorgos Papakonstantinou]

Hello student from Korea!

Why don't you try this?

q = 4; % connect every qth point out of p points 
mingon = 2*q + 1;
maxgon = mingon + 11;
jj = 0;
for ngon = mingon:maxgon;
    theta = linspace(0, 2*pi, ngon+1); 
    [xx, yy] = pol2cart(theta, 1);
    K = diag(ones(q,1), ngon-q)+diag(ones(ngon-q,1), q)+diag(ones(q,1), -ngon+q)+diag(ones(ngon-q,1), -q); % adjacency matrix

      jj = jj + 1;
      subplot(3, 4, jj)
      gplot(K, [xx' yy'])
      hold all
      plot(xx, yy)
      axis equal
      title(['\{' num2str(ngon, '%d') '/' num2str(q, '%d') '\}'])
  end

[Image Analyst]

Wow. Pretty cool.