How can i plot a structure array?

Hello all,

I have a structure array containing multiple trials. I would like to plot the singl trials, but change the trials with the arrows (so that I don't have to give the single command). I wrote this code:

for b= 1:length(fields_trials)
    plot (Trials.(['a_' int2str(a)]));
end;

[Azzi Abdelmalek]

You wrote the code, and?

[Fabio Castro]

Sorry, I forgot to write what happened. It plotted only the first trial. My structure is like Trials.a_1, Trials.a_2, ect.

[Stephen23]

@Fabio Castro: rather than using dynamic fieldnames, you should consider using a non-scalar structure. Using a non-scalar structure will make your code much simpler:

S(1).trial = [1,2,3];
S(2).trial = [4,5,6];
S(3).trial = [7,8,9];

Then accessing the contents of the structure is really simple:

>> S(1).trial % one element
ans =
   1   2   3
>> vertcat(S.trial)
ans =
   1   2   3
   4   5   6
   7   8   9

And you can use indexing to access any elements of the array:

>> vertcat(S([false,true,true]).trial)
ans =
   4   5   6
   7   8   9

Using a non-scalar array would make your code simpler, faster, and less buggy. You shoudl try it.

Answer 1

[Walter Roberson]

for b= 1:length(fields_trials)
    plot (Trials.(['a_' int2str(a)]));
    hold on
end

[Walter Roberson]

If all of the fields are vectors of the same number of data points, and you want to plot all of the fields in the structure, then you can be more efficient.

cols = cellfun(@(C) C(:), struct2cell(Trials), 'Uniform', 0);
y = horzcat(cols{:});
plot(y)

[Fabio Castro]

Hello, and thank you for your answer. I have just tried your code, but it doesn't work. all I have is just the first one. I was thinking of using the pause command?

[Walter Roberson]

Is it possible that the range of values is fairly different between the fields? If so then,

for b= 1:length(fields_trials)
    plot (Trials.(['a_' int2str(b)]));
    hold on
end
set(gca, 'xlimmode', 'auto', 'ylimmode', 'auto')

Note, by the way, the correction of int2str(a) to int2str(b). I would suggest coding

for b = 1 : length(fields_trials)
    plot( Trials.(sprintf('a_%d',b)) );
    hold on
end
set(gca, 'xlimmode', 'auto', 'ylimmode', 'auto')

And if you really wanted to get fancy:

hold on
structfun(@plot, Trials, 'Uniform', 0);
set(gca, 'xlimmode', 'auto', 'ylimmode', 'auto')

[Fabio Castro]

Ok, It works now. However, I have a plot with all the trials overlapping. On the other hand I need to be able to see the single trials, as I need to visually analyze them singularly. Any Idea?

[Walter Roberson]

Is there to be one subplot per field? Or do you want something like a waterfall plot?

[Fabio Castro]

Hello Walter,

Yes, I need to be able to plot a trial each time, and be able to go through one by one using the keyboard. This because I need to see if there is any error in the trial. The code you have sent me plots all the trials at the same time.

I hope I have express myself better.

Thank you very much for your help!