How do I remove any Column in a matrix

Please what is wrong with this function. I want it to remove 'n' column form the matrix A

function B = column_removal(A,n)
A1= A(:,1:n-1) % Index from column 1 to column 'n-1'
A2 = A(:,n+1:end) % Index from column 'n+1' to the last co1umn
  B = [A1 A2] % concatenate A1 & A2 by which the n column would have been removed
end

[Ive J]

A(:, n) = []; 

[Cutie]

Can you please explain?

[Mathieu NOE]

A(:, n) = [];

means that the 'n' th column has been flushed

[Cutie]

Thank you, but how do I assign the above output to a variable.

Answer 1

[Matt J]

Nothing is wrong with the code you've posted, but it would be simpler to do,

 B=A(:,[1:n-1,n+1:end]);

or, slightly less efficiently,

 B=A;
 B(:,n)=[];

[Cutie]

Thank you @Matt J but the function still shows error when I ran it....It's displaying 'Not enough input arguments.

[Walter Roberson]

B = A(:, setdiff(1:end, n))

is another way to write it that is sometimes easier to think about, especially once you start getting multiple exclusions.

[Cutie]

Thank you @Matt J @Walter Roberson & @ercan duzgunfor your response. I am newbie to MATLAB, so plase tolerate my seeming elementary questions, I know the line of code (I wrote above work). But I created it as a function & saved. When I open the function and click run, this is when I get this response 'Not enough input arguments.'

[Walter Roberson]

You opened the function in the editor and you clicked on the green Run button. When you did that, MATLAB had no idea what A and n should refer to.

You need to go down to the command line and pass in values, such as

A = magic(12)
B = column_removal(A, 4)

[ercan duzgun]

Cutie, you can't use MATLAB "function" by clicking "run" button. After creating and saving the function (file name have to the same function name. For your case, file name have to be "column_removal.m"), just close it. You can call and use the function in your program scripts now. For example, in command window: just type the command of

>>X=[1 2 3 4 5 6; 10 20 30 40 5 60;100 200 300 400 500 600]

>> column_removal(X,3)

Or you can use the funciton in your another MATLAB programme script file. Run button works with MATLAB "script" files, but not with "function" files.

[Cutie]

@Matt J, @ercan duzgun & @Walter Roberson thank you so much. I learnt something with your response.

[Image Analyst]

And Walter of course!

You can accept the Answer below to give ercan "credit" for helping you in terms of "reputation points". Thanks in advance.

[Cutie]

I wanted to but the 'Accept answer' is not there. That's why I voted it,

Answer 2

[ercan duzgun]

Dear Cutie,

Your MATLAB function already works fine. However, Matt J's solution is simpler.

I checked your MATLAB function by this example below, and I received the expected result.

X=[1 2 3 4 5 6; 10 20 30 40 5 60;100 200 300 400 500 600]
column_removal(X,3)
A1 =

     1     2
    10    20
   100   200


A2 =

     4     5     6
    40     5    60
   400   500   600


ans =

     1     2     4     5     6
    10    20    40     5    60
   100   200   400   500   600

[Cutie]

Thank you.