MATLAB Central Newsreader - Best way to loop through unknown structure

Best way to loop through unknown structure

Karl Trumstedt — Wed, 15 Aug 2007 09:05:40 -0400

Here is what I am using right now. I am wondering if there
is any other way to do it. Say that I want to convert each
structure field to one regular variable. What is the best
method do you think?

x = struct(...)

if isstruct(x)
    s = fieldnames(x);
    for i=1:length(s)
        assignin('caller', char(s(i)), x.(char(s(i)));
    end
end

/ Karl
Developer @ Lundin Mining AB
http://www.lundinmining.com/index.php
Developer @ Kolonn AB http://www.kolonn.se

Re: Best way to loop through unknown structure

Titus — Wed, 15 Aug 2007 09:19:35 -0400

"Karl Trumstedt" <karltru@gmail.com> schrieb im Newsbeitrag
news:f9ufl4$tb$1@fred.mathworks.com...
> Here is what I am using right now. I am wondering if there
> is any other way to do it. Say that I want to convert each
> structure field to one regular variable. What is the best
> method do you think?
>
> x = struct(...)
>
> if isstruct(x)
> s = fieldnames(x);
> for i=1:length(s)
> assignin('caller', char(s(i)), x.(char(s(i)));
> end
> end
>
> / Karl
> Developer @ Lundin Mining AB
> http://www.lundinmining.com/index.php
> Developer @ Kolonn AB http://www.kolonn.se

Hi,
the only suggestion I would have is to use a simpler call
into the cell arrays:
assignin('caller', s{i}, x.(s{i}));
but that's all. Perhaps you could tell us, why you would
need something like that?

Titus

Re: Best way to loop through unknown structure

Karl Trumstedt — Wed, 15 Aug 2007 09:27:43 -0400

"Titus" <titus.edelhofer@mathworks.de> wrote in message
<f9ugf5$9v2$1@fred.mathworks.com>...
>
> "Karl Trumstedt" <karltru@gmail.com> schrieb im
Newsbeitrag
> news:f9ufl4$tb$1@fred.mathworks.com...
> > Here is what I am using right now. I am wondering if
there
> > is any other way to do it. Say that I want to convert
each
> > structure field to one regular variable. What is the
best
> > method do you think?
> >
> > x = struct(...)
> >
> > if isstruct(x)
> > s = fieldnames(x);
> > for i=1:length(s)
> > assignin('caller', char(s(i)), x.(char(s(i)));
> > end
> > end
> >
> > / Karl
> > Developer @ Lundin Mining AB
> > http://www.lundinmining.com/index.php
> > Developer @ Kolonn AB http://www.kolonn.se
>
> Hi,
> the only suggestion I would have is to use a simpler call
> into the cell arrays:
> assignin('caller', s{i}, x.(s{i}));
> but that's all. Perhaps you could tell us, why you would
> need something like that?
>
> Titus
>
>

Hi,
I'm mostly just experimenting :) Always nice to have more
matlab knowledge ;)

I also have a "few" structs with data that I would like to
make available for the user to use in the interactive
plotting tool. I haven't really played around with it, so
it might be possible to use the structs to plot, making it
unnecessary to convert the structs.

Cheers
/ Karl
Developer @ Lundin Mining AB
http://www.lundinmining.com/index.php
Developer @ Kolonn AB http://www.kolonn.se

Re: Best way to loop through unknown structure

Loren Shure — Wed, 15 Aug 2007 19:51:08 -0400

In article <f9ufl4$tb$1@fred.mathworks.com>, karltru@gmail.com says...
> Here is what I am using right now. I am wondering if there
> is any other way to do it. Say that I want to convert each
> structure field to one regular variable. What is the best
> method do you think?
>
> x = struct(...)
>
> if isstruct(x)
> s = fieldnames(x);
> for i=1:length(s)
> assignin('caller', char(s(i)), x.(char(s(i)));
> end
> end
>
> / Karl
> Developer @ Lundin Mining AB
> http://www.lundinmining.com/index.php
> Developer @ Kolonn AB http://www.kolonn.se
>

See this blog post today on looping through non-numeric arrays:

http://blogs.mathworks.com/loren/2007/08/15/iterating-over-non-numeric-
values/

I think you have an extra level of indexing that you can do without.

--
Loren
http://blogs.mathworks.com/loren/

Re: Best way to loop through unknown structure

us — Wed, 15 Aug 2007 20:34:23 -0400

Karl Trumstedt:
<SNIP wants to infest his/her clean workspace with numerous
field data...

one of the (unconventional) solutions

% the data
     s.a=1:5;
     s.b=pi;
     s.c=magic(4);
% the engine
     fnam='foo.mat'; % <- use your own test file!
     save(fnam,'-struct','s');
% the result
     clear a b c s; % !
     load(fnam);
     a
     b
     c

us