Arrange (array of 9 numbers) in ascending order. (no sort)

Please suggest me to find a commnad using for loop to Arrange (array of 9 numbers) in ascending order without using sort command. I used the following one, which didn't work

A = [4 16 36 64 1 9 25 49 81] B = [] for i = 1:9

B(i) = max(A)

find max(A)== 0

end

[per isakson]

Google for "bubble sort"

[Aviroop Dutt Mazumder]

Thanks per, it worked! Do i need to do the same for descending numbers? Cheers

Answer 1

[Honglei Chen]

You can do

B = unique(A)

But seriously, are you trying to implement a sort algorithm in MATLAB? If so, there are many algorithms available, e.g., quick sort

http://en.wikipedia.org/wiki/Quicksort

[Aviroop Dutt Mazumder]

Thanks Honglei, I used the bubble command to get the number output in an ascending order

Answer 2

[Jan]

Improvement of your method:

A = [4 16 36 64 1 9 25 49 81];
B = zeros(1, 9);  % Pre-allocate!
for ii = 1:9
  [value, index] = max(A);
  B(ii) = value;
  A(index) = -Inf;
end

For 9 elements an insert-sort would be fine also.

[Safwan]

Can you please explain to me why did you put

 A(index) = -Inf;

[Image Analyst]

So that element of A will no longer be found as the maximum value of A in subsequent iterations. If you didn't do this, it would simply find the very same value of A each iteration!

[James Tursa]

This is to eliminate that particular element from the result of the next max(A) calculation, since that element has already been placed into the B vector.

[Larissa Monjaraz]

How would the code change if you wanted it in descending order?

[Walter Roberson]

use min and +inf

[Larissa Monjaraz]

Ooooh that makes sense. Thank you!