create a function handle extracting pieces from a matrix function handle

I created a Matrix function using function handle @ like

A=@(x) [1 2 x; 2*x x.^2 3]; %it's an example

i need to create another function extracted from the previous one

B=@(x) A(x) without the second column

therefore size(A)=2x3 and size(B)= 2x2;

if it wasn't for the handle: B=A(:,[1 3])

ty for your help

Answer 1

[Kye Taylor]

Starting from your example

A = @(x) [1 2 x; 2*x x.^2 3];

you probably realized that this command is not allowed

B = @(x)[A(x)(:,1),A(x)(:,3)]

However, you can use this command:

B = @(x)[A(x)*[1;0;0],A(x)*[0;0;1]]

[Sergio Codeluppi]

ty for your help, i actually didn't think of this :)

Answer 2

[Walter Roberson]

B=@(x) subsref(A(x), struct('type', '()', 'subs', {':', [1 3]}));

Note: if the requirement is "all of whatever is there, except column 2", rather than "select only column 1 and column 3", then in order to avoid evaluating A(x) twice, one would have to add a helper anonymous function (because a subscript of 'end' is not allowed at the subsref level and must be converted to numeric form.)

[Sergio Codeluppi]

i actually don't know command subsref, but tried your way and i get this

Error using subsref The "subs" field for the subscript argument to SUBSREF and SUBSASGN must be a cell or character array.

ty anyway for your help!