what would the code look like?

Write a function that takes an odd square matrix as an input. This function must then sum the four corner elements of the matrix to a value and multiply said value against the middle column vector of the matrix. The first line of your function should look like this:

function Ans = MatrixFun (A)

this is what i have so far..

 in my workspace.... A = [1 2 3;4 5 6;7 8 9]

as a function.....

function Ans = MatrixFun(A)
  [c d] = size(A)
  Ans = (A(1,1)+A(1,c)+A(c,1)+A(c,c))*A(:,2);
end

[dpb]

And the specific question is???

BTW, test your function on

MatrixFun(rand(5))

[LG]

we upload the .m files and get feedback.. the function runs and the answer is correct BUT i have not satisfied one of the conditions.....

 "Code is not detecting incorrect input ie. It is not detecting if a matrix is even or non-square"

[LG]

i have no clue what that means

[James Tursa]

Insert a check in your function:

function Ans = MatrixFun(A)
  [c d] = size(A);
  if( A is even or A is non-square )
      error('Input matrix is not even or non-square');
  end
  Ans = (A(1,1)+A(1,c)+A(c,1)+A(c,c))*A(:,2);
end

You just need to put in the actual code for the "A is even or A is non-square" part. E.g., if you have the size of the matrix in c an d, how can you use those to check if a matrix is non-square? How do you check to see if it is even? Write those conditions out and put them inside the if-check.

[dpb]

>>  A=rand(5);
>> [c d]=size(A);
>> Sum= (A(1,1)+A(1,c)+A(c,1)+A(c,c))
Sum =
  2.5707
>> Ans = (A(1,1)+A(1,c)+A(c,1)+A(c,c))*A(:,2);
>> [A Ans]
ans =
  0.7856    0.0309    0.4671    0.8541    0.6628    0.0794
  0.5134    0.9391    0.6482    0.3479    0.3308    2.4143
  0.1776    0.3013    0.0252    0.4460    0.8985    0.7746
  0.3986    0.2955    0.8422    0.0542    0.1182    0.7597
  0.1339    0.3329    0.5590    0.1771    0.9884    0.8559
>>

You're going to try to tell me that 2.57*"MiddleColumnOfA" is the answer shown in the last column above????

I don't think so...