MATLAB: How to write a program to draw a triangle of stars in MATLAB

homework

I have a exam and don't know how to write a program to draw a triangle of stars, for example :

       *
       **
       ***
       ****
       *****
And also flip upside down, for example :
            *
           **
          ***
         ****
        *****
And also in the form of isosceles triangle, for example :
             *
            ***
           *****
          *******
And also in the form of a specific, for example :
             *
            ***
           *****
          *******
           *****
            ***
             *

Please help me!

Best Answer

Hint:

string = '     '; % 5 spaces.
index1 = 2;
index2 = 4;
string(index1:index2) = '*';
fprintf('%s\n', string);

You need to figure out what index1 and index2 are for the various lines you want to print out.

Related Solutions

MATLAB: Problem including tolerance and finding value of a certain term

If you're checking for a certain tolerance, you can, after each iteration, see if the value of your most recently calculated term is less than the tolerance value. However, since you don't know when this will occur, a FOR loop probably isn't your best bet. After all, what happens if you don't reach the tolerance in the number of iterations you've set?

So, a better strategy here would be a WHILE loop. You set a certain condition: until your most recent term is less than or equal to tol, you continue to iterate. Since you still need your n values to increment for each iteration, you just set n to your starting index (e.g. 1) at the beginning and perform n = n + 1 at the end of each iteration.

tol = 1e-5;
x = input('Select value of x = ');
S = 0;
n = 1;
while Si > tol
  Si = ((-1) ^ (n-1)) .* (((x - 1) .^ n)./n);
  S = S + Si;
  n = n + 1;
end
disp(' ') fprintf('S(x,n) = %8.4f\n; n = %i' ,S,n-1)

MATLAB: Help.. how would i get 7* to 1*

You can run the for-loop in reverse order too

N = 7; 
for mm = N:-1:1 % equivalent to mm = flip(1:N)
    for nn = 1:mm
        fprintf('*');
    end
    fprintf('\n');
end

Best Answer

Related Solutions

MATLAB: Problem including tolerance and finding value of a certain term

MATLAB: Help.. how would i get 7* to 1*

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