How to Get a Structure as an Output from a Function?

I have this function made to sort data into a structure. However, when I call a directory as the input, I can't seem to get an output. I call it by doing

filesort(dir([foldername(1).standard,'\*.dat'])).

However, when I set x=sortdata(dir([foldername(1).standard,'\*.dat'])), within the function and run it, I get my desired Srt structure.

Any ideas?

[Stephen Cobeldick]

Original question by Ibro Tutic on 11th of May 2017 retrieved from Google Cache:

http://web.archive.org/web/20201226065926/https://webcache.googleusercontent.com/search?q=cache%3A3av-YLdEh_0J%3Ahttps%3A%2F%2Fwww.mathworks.com%2Fmatlabcentral%2Fanswers%2F339839-how-to-get-a-structure-as-an-output-from-a-function

How to Get a Structure as an Output from a Function?

I have this function made to sort data into a structure. However, when I call a directory as the input, I can't seem to get an output. I call it by doing

filesort(dir([foldername(1).standard,'\*.dat'])).

However, when I set x=sortdata(dir([foldername(1).standard,'\*.dat'])), within the function and run it, I get my desired Srt structure.

Any ideas?

This is the function:

function []=filesort(x)
C = {'Z1P'};
S = x;
fun = @(s)cellfun('isempty',regexp(s,C,'once'));
idx = cellfun(@(s)any(~fun(s)),{x.name});
Srt.Standard(1).Z1P = S(idx);
C = {'Z2P'};
S = x;
fun = @(s)cellfun('isempty',regexp(s,C,'once'));
idx = cellfun(@(s)any(~fun(s)),{x.name});
Srt.Standard(1).Z2P = S(idx);
C = {'Z1G'};
S = x;
fun = @(s)cellfun('isempty',regexp(s,C,'once'));
idx = cellfun(@(s)any(~fun(s)),{x.name});
Srt.Standard(1).Z1G = S(idx);
C = {'Z2G'};
S = x;
fun = @(s)cellfun('isempty',regexp(s,C,'once'));
idx = cellfun(@(s)any(~fun(s)),{x.name});
Srt.Standard(1).Z2G = S(idx);
C = {'Z3K'};
S = x;
fun = @(s)cellfun('isempty',regexp(s,C,'once'));
idx = cellfun(@(s)any(~fun(s)),{x.name});
Srt.Standard(1).Z3K = S(idx);
C = {'Z4K'};
S = x;
fun = @(s)cellfun('isempty',regexp(s,C,'once'));
idx = cellfun(@(s)any(~fun(s)),{x.name});
Srt.Standard(1).Z4K = S(idx);
C = {'Z5K'};
S = x;
fun = @(s)cellfun('isempty',regexp(s,C,'once'));
idx = cellfun(@(s)any(~fun(s)),{x.name});
Srt.Standard(1).Z5K = S(idx);
C = {'Z3M'};
S = x;
fun = @(s)cellfun('isempty',regexp(s,C,'once'));
idx = cellfun(@(s)any(~fun(s)),{x.name});
Srt.Standard(1).Z3M = S(idx);
C = {'Z4M'};
S = x;
fun = @(s)cellfun('isempty',regexp(s,C,'once'));
idx = cellfun(@(s)any(~fun(s)),{x.name});
Srt.Standard(1).Z4M = S(idx);
C = {'Z5M'};
S = x;
fun = @(s)cellfun('isempty',regexp(s,C,'once'));
idx = cellfun(@(s)any(~fun(s)),{x.name});
Srt.Standard(1).Z5M = S(idx);
C = {'Z6MS'};
S = x;
fun = @(s)cellfun('isempty',regexp(s,C,'once'));
idx = cellfun(@(s)any(~fun(s)),{x.name});
Srt.Standard(1).Z6MS = S(idx);
C = {'Z7PR'};
S = x;
fun = @(s)cellfun('isempty',regexp(s,C,'once'));
idx = cellfun(@(s)any(~fun(s)),{x.name});
Srt.Standard(1).Z7PR = S(idx);
C = {'Z7PR1'};
S = x;
fun = @(s)cellfun('isempty',regexp(s,C,'once'));
idx = cellfun(@(s)any(~fun(s)),{x.name});
Srt.Standard(1).Z7PR1 = S(idx);
end

Answer 1

[Stephen Cobeldick]

You did not define your function to have any output:

function []=filesort(x)
         ^^ no output argument!

Also your code is much longer and much more complicated than it needs to be. Try this (I just tested it):

function otpS = filesort(inpS)
C = {'Z1P','Z2P','Z1G','Z2G','Z3K','Z4K','Z5K','Z3M','Z4M','Z5M','Z6MS','Z7PR','Z7PR1'};
N = {inpS.name};
otpS = struct();
for k = 1:numel(C)
    idx = cellfun('isempty',regexp(N,C{k},'once'));
    otpS.(C{k}) = inpS(~idx);
end
end

Tip: computers are only good at doing one thing: repeatedly doing small stupid tasks. So when you find yourself copy-and-pasting code like that, and repeating the same code over and over again, then you are doing the computer's job. Instead of wasting your life, get the computer to do it: use a loop.

[Ibro Tutic]

even doing

function [y]=filesort(x)

and calling

filesort(dir([foldername(1).standard,'\*.dat']))

I still don't receive an output (which I would assume should be y?)

Edit: I got it to work with the above code, within the function itself I needed to set y=Srt to get an output.

[Ibro Tutic]

That is exactly what I was trying to on my own, but couldn't get it to work. Thanks a lot for the help.

[KL]

Stephen has assigned otpS as the function output, if you call from command line

y = filesort(x)

then the function return will be saved under y.