write a three_max function

* not a homework question. This is a practice question for an upcoming exam

Write a function, three_max, which takes three numbers, x1, x2, x3 and outputs the largest number. Do this without using the variety of built-in functions associated with max and sort. Test it.

I have created a function but when ever I try to test it I get a "not enough input arguments" for line 2: if (x1>x2 && x1>x3). I do not know what I am doing wrong

function three_max(x1,x2,x3)
    if (x1>x2 && x1>x3)
        max=x1;
    elseif (x2>x1 && x2>x3)
        max=x2;
    elseif (x3>x1 && x3>x1)
        max=x3;
    end 
end 

[Thanishq]

hii

this is the program i did :

function [p] = three_max(a,b,c)

if a>b && a>c

p=a;

elseif b>a && b>c

p=b;

else

p=c;

end

As u have this problem:"I have created a function but when ever I try to test it I get a "not enough input arguments" for line 2: if (x1>x2 && x1>x3). I do not know what I am doing wrong "

after writing the code we just simply click run button but in command prompt we have to write this....

>> three_max(1,2,3)

ans =

3

Answer 1

[Daniel M]

There are several issues with your code.

1. It does not return an output.
2. It overloads the max() function, which can lead to confusing issues.
3. Your third conditional (which isn't necessary at all) compares against x1 twice.

Finally, I do not get the stated error when I run this code. It must be how you are calling it. Perhaps you have done:

three_max(x1,x2)

The function requires three inputs.

[Britnie Casillas]

I am very new so i do not know how to change it to have an output. In addition, how do I not overload max(x) function?

I have fixed the last part. However, even when I run three_max(1,2,3) for example I get a blank answer/no response and then I type just three_max into the workspace it still comes up with the same error.

[Daniel M]

Oh I see. Yes, you need to return an output.

You avoid overloading by not naming variables after built-in functions. I know you are avoiding using the max function in this case, but it's still bad practice. Say, for example, in your function you wanted to compare your answer to the value returned from max, how would you call that function? You can't because you have set max = x1 (or x2, or x3). This should work now.

function x = three_max(x1,x2,x3)
    if (x1>x2 && x1>x3)
        x = x1;
    elseif (x2>x1 && x2>x3)
        x = x2;
    elseif (x3>x1 && x3>x2)
        x = x3;
    end 
end

Call the function with

maxVal = three_max(x1,x2,x3)

[Britnie Casillas]

I believe it works now!

When I type three_max(1,10,5) in the command window, it returns with the highest value, in this case 10. I think is what my professor is looking for!

Thank you!!