Indexing of fresh array in one line without intermediate variable.

How do I index a newly made array without intermediate variables?

Maybe not the best example, but imagine I want to do this

    regexp(string,expression,'match')(10:20)

How do I do it in one line?

It is not a regexp question. This problem occurs in many different situations. Thank you

EDIT Another example

function ans = Func(array)
array
end

I want it to look like

Func(1:10)(2:3)

But I need to do

temporary = Func(1:10);
temporary(2:3)

EDIT2. Finally found the answer here: http://stackoverflow.com/questions/3627107/how-can-i-index-a-matlab-array-returned-by-a-function-without-first-assigning-it

[Azzi Abdelmalek]

Give an example

[Maxim]

Any function that gives out an array.

[UniqueWorldline]

For anyone finding this question as late as I have, but who is looking for a simple solution for the

size

function, do the following to only get the one index of the array size you are looking for:

A = [1,2,3,4,5]; % Some array
arrayCols = size(A); % This returns a 1x2 array with the number of rows 
                     % and columns of A. Which is undesirable if only 
                     % the columns are wanted. Instead do this:

[arrayRows,arrayCols] = size(A);

Now arrayCols is a scalar value that can be used immediately. This doesn't allow you to do

size(A)(2)

but it can still eliminate an intermediate.

[Stephen23]

"This returns a 1x2 array with the number of rows and columns of A."

No. Strictly speaking that actually returns the combined size of all dimensions >=2. Lets try it now:

A = rand(5,4,3);
[rows,notcolumns] = size(A)

rows = 5

notcolumns = 12

If you really want the number of columns only then the simple and reliable approach is this:

size(A,2)

ans = 4

Answer 1

[Maxim]

From http://stackoverflow.com/questions/3627107/how-can-i-index-a-matlab-array-returned-by-a-function-without-first-assigning-it

Problem

magic(5)(3)

Solution 1

value = subsref(magic(5),struct('type','()','subs',{{3,3}}));

Solution 2

paren = @(x, varargin) x(varargin{:});
paren(magic(5), 3, 3);

[Jose Daniel Ortiz]

So, basically, Matlab does not really support execution and indexing in the same line. This is in contrast to python, in which you can have ludicrously and arbitrarily complex chains of computation in a single line such as:

thing = A(B(size(A)(0))(0))

[Walter Roberson]

MATLAB does "really" support execution and indexing in the same line, but the syntax for it is pretty ugly. And you need a real assignment in order to capture any output after the first output from a function that returns multiple outputs.

Answer 2

[Azzi Abdelmalek]

Look at

cellfun

arrayfun

Example

 a=[2 3 5 8]
out=arrayfun(@(x) x^2+sin(x),a)

[Maxim]

I know these functions, but don't see how they could be helpful. The problem is that I can't index the fresh array.

Answer 3

[DH]

Hope this helps.

interp1(Func(1:10), 2:3)