I have a matrix BB = [-1 5 6;4 -3 2;5 6 -7]. How can i print the location(index) of the positive elelments using for loop and using while loop ?

I have this matrix BB = [-1 5 6;4 -3 2;5 6 -7]. I want to know how can I display the location of the positive elements using for loop and using while loop

[Paolo]

I am assuming this is a homework question as we did the while loop in the previous question.

For educational purposes, it would be good to see your attempt. What have you tried and what are you having trouble with?

[Fares Alfares]

I tried to do this for the for loop:

for BB = [-1 5 6;4 -3 2;5 6 -7]
i = [1:length(BB)]
if (BB(i) >= 0)
i
end
end

but it gave me :

i =

       1     2     3

i =

       1     2     3

i =

       1     2     3

I didn't try for the while loop yet

[Paolo]

That's not the correct syntax for a for loop. Check this documentation page: link

[Fares Alfares]

I tried to do this i=[1:length(BB)] for BB = [-1 5 6;4 -3 2;5 6 -7] if (BB(i) >= 0) i end end it gave me :i =

     1     2     3
and I tried to do 
BB = [-1 5 6;4 -3 2; 5 6 -7]
i = [1:length(BB)]
for (BB(i)>= 0)
i
end
it gave me :BB =

    -1     5     6
     4    -3     2
     5     6    -7

i =

     1     2     3

 for (BB(i)>= 0)
        ↑
Error: Invalid expression. When calling a function or
indexing a variable, use parentheses. Otherwise, check for
mismatched delimiters.

Answer 1

[KSSV]

BB = [-1 5 6;4 -3 2;5 6 -7] ;
[nx,ny] = size(BB) ;

for i = 1:nx
    for j = 1:ny
        if BB(i,j)>0
            fprintf('%d %d %f\n',i,j,BB(i,j))
        end
    end
end

[Fares Alfares]

it gave me this : 1 2 5.000000 1 3 6.000000 2 1 4.000000 2 3 2.000000 3 1 5.000000 3 2 6.000000

but can you give me a way by using while loop

[Fares Alfares]

Thank you very much the for loop code works, but I need another way by using the while loop

[Fares Alfares]

Thank you very much it works. I figured a way by using while loop