stars pattern using recursive function HELP

My teacher is asking us to create a triangle of stars with a recursive function. Can someone help me ? I've got something but it's not a recursive function. This is what i have :

function [ x ] = Triangle( x )

for i = 1:x
    for j = 1:x-i
        x=fprintf(' ');
    end
    for c = 1:i;
        x=fprintf('*');
    end
    fprintf('\n');
end

triangle(7)

      *
     **
    ***
   ****
  *****
 ******
*******

Answer 1

[Jan]

Do you know, what a recursive function is? You have to include a call to itself in the code. But this should not cause an infinite recursion, therefore you have to modify the inputs and outputs, such that the calling will end.

function Triangle(x)
disp(x)
if x > 0
  Triangle(x - 1);
end
end

Now fill in your code to draw the stars.

By the way: repmat('*', 1, x) helps to create the string without a loop. See also:

sprintf('%20s', 'hello')

This fills in spaces on the left, such that the output has at least 20 characters.

[Jan]

This is easier than the loops:

fprintf('%10s\n', repmat('*, 1, x))

Or:

fprintf('%s%s\n', repmat(' ', 1, 10-x), repmat(' ', 1, x));

Most of all omit the "for i = 1:x" loop. Remember that you have replaced this loop by the recursion.

[Jade Corbeil]

Great thank you a lot !! :)