Hi,I've tried everything to do prob 3 and 4 but I couldn't succeed.Can someone provide me the code for prob 2, 3,and 4 especially 3 and 4.Thankyou

This problem will test your variable handling skills.

(a) Write a function called hiddenSum that takes two inputs and returns the sum of the two inputs. Turn in a printout of the function.

(b) Write a script M-file called testHiddenSum.m that defines two variables x and y Assign some values to these variables. Call the function hiddenSum from within this script M-file and store the result in a local variable, z. Run the script M-file and turn in a printout with the value of z.

(c) Modify the function hiddenSum such that now it DOES NOT HAVE any output arguments. Now modify your script M-file such that it calls hiddenSum using x and y as inputs and assigns the result to the variable z. You will need to further modify your function file. Submit a printout of the new function and script files and command prompt results from running your script M-file.

(d) Now modify your function hiddenSum such that it DOES NOT HAVE any input OR output arguments. Modify your script M-file such that it calls hiddenSum using x and y as inputs, and stores the result in the variable z. You will need to further modify your function file. Submit a printout of the new function and script files, and the command prompt results from running your script M-file.

[Steven Lord]

Since this is 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 MATLAB Onramp tutorial (https://www.mathworks.com/support/learn-with-matlab-tutorials.html) 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.

[ajeet sahu]

Thankyou for reply.But it is not true that it's my homework.I'm learnig matlab by doing different types of questions and found this on internet.I had written the function and script file for 'a' and 'b' but in the 'c' part I can't store the result of function(without output argument) into variable in the script.I'm getting error(Too many output arguments on doing z=testHiddenSum(x,y) in script).Also it is very difficut to this again for part 'd' when function has no input and output arguments. Here is the function code for 'c'

 function hiddenSum(a,b)
    a+b
 end

Here is script for 'c'

 clc;clear;
 x=input('Enter value of x\n');
 y=input('Enter value of y\n');
 z=hiddenSum(x,y)

Also I couldn't find how to do 'd' without input arguments to function.

Please help.Thankyou

[Steven Lord]

Please show us what you wrote for part c.

[ajeet sahu]

Please check.I've updated previous comment.

[ajeet sahu]

Please help sir,I've already provided my code.I tried yesterday also but couldn't.

[per isakson]

AFAIK: the exercises c) and d) can only be solved using the functions

assignin( 'caller', ... )
evalin( 'caller', ... ) 

or (in your case)

assignin( 'base', ... )
evalin( 'base', ... ) 

These are regarded (with good reasons) to be anti-patterns. In this forum a lot of effort has been spent to discourage constructs like those needed to solve c) and d).

[David Goodmanson]

Hi ajeet,

another way to accomplish this, more or less, is with globals:

% exercise d)
global x y z
x = 3;
y = 4;
fun
z             % answer is 7
  
function fun
global x y z
z = x+y;
end

However, like the method that per mentioned, this way is also fraught with opportunities for error and, in larger programs, funny results that can be extremely hard to debug. Along the lines of what per was saying, it would be best to forget about c) and d) and concentrate on much better and more direct ways to use functions. No point in 'mastering' an inferior technique that is known to cause all kinds of problems.

[ajeet sahu]

Thankyou very much.I thought if this is important for learning matlab properly.As you said we should not do 'mastering' in inferior techniques that can cause error.Also as you said it is not good to do all variables as global and somehow produce the result.I'll forget 'c' and 'd' bcz it looks like it is not useful in comman matlab practices.

[ajeet sahu]

Also I actually doesn't get that to do that even with assignin or evalin function so the result is assigned to z.

[per isakson]

Promise not to use this

%% 
x = 1;
y = 2;
%%
hiddenSumC( x, y );
%%
hiddenSumD();
%%
disp( [zC,zD] )

     3     3

%%
function    hiddenSumC( x, y )
    z = x + y;
    assignin( 'base', "zC", z );
end
function    hiddenSumD()
    x = evalin( 'base', "x" );
    y = evalin( 'base', "y" );
    z = x + y;
    assignin( 'base', "zD", z );
end

And btw, I've forgotten there is a command, global. I never use it.

[ajeet sahu]

Haha promised. This code actually does the complete job for prob 'c' and 'd'.Matlab never disappoint us.Thankyou very much for complete answer.