Extract a column of a matrix created by a command

I have a matrix that was created by a command. Let's say

magic(4)

Now I want to extract a specific elemnt from this matrix. Of course, I can do that using the commands for selecting subsets of elements from the matrix.

So that extracting the 3rd element from magic(4) means:

1. to store magic(4) in a variable: M=magic(4)
2. M(3) selects the 3rd element.

My question is whether this could be made using only one command. My first trial was these two, but neither worked:

magic(4)(3)
(magic(4))(3)

Any help would be much appreciated!

Answer 1

[Stephen23]

MATLAB does not generally support indexing** directly into the output of functions or operations. The usual solution is to allocate to a temporary variable. If you want this feature then please submit an enhancement request.

You could use subsref to do this without a temporary variable, but it would be obfuscated and complex code that you will later regret writing. I do not recommend doing this.

** Version R2019b and later allows dot indexing into function outputs, see:

https://www.mathworks.com/help/matlab/matlab_prog/indexing-into-function-call-results.html