how to write a function to find max & min value in array

hi every one I really need your help in this question write a function m.file to find the maximum and minimum number in array *do not use the built in functions in matlab* ? i know how to find it but i don't know how to make a function ?? could anyone help me ?

[Hakim]

Proper answer needed

[Steven Lord]

Since this is likely a homework assignment, show us the code you've written to try to solve the problem and ask a specific question about where you're having difficulty and we may be able to provide some guidance.

If you aren't sure where to start because you're not familiar with how to write MATLAB code, I suggest you start with the free MATLAB Onramp tutorial to quickly learn the essentials of MATLAB.

If you aren't sure where to start because you're not familiar with the mathematics you'll need to solve the problem, I recommend asking your professor and/or teaching assistant for help.

If you're asking for a "proper answer" to the question as originally asked, that question is impossible since the relational operators like > and <= are built-in functions in MATLAB.

Answer 1

[Andrei Bobrov]

try it

function [ma mi] = alifun(A)
  aw = A(:);
  ma = aw(1);
  mi = aw(1);
  for  i1 = 2:numel(aw)
     if ma < aw(i1), ma = aw(i1);
     elseif mi > aw(i1), mi = aw(i1);  
     end
  end
end

[Lauren Passio]

What does the "aw" mean?

Answer 2

[Paulo Silva]

Have a look at Doug’s MATLAB Video Tutorials and Declare function

After you watch those nice video tutorials about functions and read the documentation try to do your function and if you have any specific question please ask and we will be here to help you.

[ahmed ali]

thank you , but is it the right way to write the function like this ??

function[maximum,minimum]=array(a)
    maximum=array(1);
    minimum=array(1);
    for i=1:length(Array)
        if Array(i)>Maximum
            Maximum=Array(a);
        end
        if Array(i)<Minimum
            Minimum= Array(a);
        end
    end
    
    disp('The Masximum is: ')
    Maximum
    disp('The Minimum is: ')
    Minimum
end

[ahmed ali]

still there's error if i run the programme !

-___-

[Image Analyst]

You wrote the function incorrectly. You don't want this to be a recursive function so don't call array() inside of array(). You should have used a() instead of array() because a is the matrix while array is your function's name. Also note that MATLAB is case sensitive so Array and array are different.

[Image Analyst]

Also note that you used the wrong index, "a" instead of i. It should be

if Array(i)>Maximum

Maximum=Array(i);

end

or better yet, don't use i and j as indexes at all since they are the imaginary constants.

[ahmed ali]

thank you , i understand know =)

Answer 3

[Dave Correa]

Hello;

You can to use the following code;:

example:

>> array=magic(8)

>> [maximum,minimun]=find_maxmin(array)

maximun =

    64

minimun =

     1

Regards,

Dave Correa

[e-mail]

http://fismatlab.blogspot.com/

function [maximum,minimun]=find_maxmin(array)

maximun=max(max(array))
minimun=min(min(array))

[Dave Correa]

I think that this would be the simplest way to define a search function for maximum and minimum of a data matrix.

regards

Dave

[Image Analyst]

Yes, except this was a homework problem where his instructor said not to use built in functions like max and min.

Answer 4

[Mohammed Raihan]

function[Max, Min]=minimax(M)
    Max=max(M')-min(M');
    maxa=max(M');
    maxa2=max(maxa);
    mini=min(M');
    mini2=min(mini);
    Min=maxa2-mini2;
end

[DGM]

This does not meet the requirements of the original question. The original question requires that min() and max() aren't used.