loading multiple groundtruth .mat files

Hi and good day to all,

I have 8 ground truth labelled .mat files from videos done by the matlab labeller.

I am trying to load such and I am uncertain of the next move.

Can a profession assist me please?

I have gotten this far with google, here's my code!

Thank you in advance!!

filenames = {'Beat1GTruth.mat','Beat2GTruth.mat','Fight1GTruth.mat','Fight2GTruth.mat','Shoot1GTruth.mat'...
    ,'Shoot2GTruth.mat','Stab1GTruth.mat','Stab2GTruth.mat'};  
for kk = 1:numel(filenames)
    load(filenames{kk})
end

Answer 1

[Stephen23]

Always load into an output variable (which is a scalar structure), e.g.:

F = {'Beat1GTruth.mat', 'Beat2GTruth.mat', 'Fight1GTruth.mat', 'Fight2GTruth.mat', 'Shoot1GTruth.mat', 'Shoot2GTruth.mat', 'Stab1GTruth.mat', 'Stab2GTruth.mat'};
N = numel(F);
C = cell(1,N);
for kk = 1:N
    S = load(F{kk}); % load into a structure
    % you can do anything with the structure contents, e.g.:
    C{kk} = S.somefield; % !!! use an appropriate fieldname !!!
end

See also:

https://www.mathworks.com/help/matlab/import_export/process-a-sequence-of-files.html

https://www.mathworks.com/help/matlab/matlab_prog/access-data-in-a-cell-array.html

[Matpar]

Hi Stephen Cobeldick and good morning to ya!

What is this piece of code can you describe it and thank you in advance for responding to me so swiftly

S.somefield?!!!???

C{kk} = S.somefield; % !!! use an appropriate fieldname !!!

[Matpar]

Hi Stephen Cobeldick,

I tried understanding the links you sent and I am not getting it! can you help me to understand please?

I am trying to have as my output file one variable as a table so I can proceed.

I am stuck at this level for some time just trying to figure out how to load all of these mat files at once and then proceed. please help!

[Matpar]

Hi Stephen Cobeldick,

My apologies, I uploaded the data files so that you can see what I am trying to load

[Matpar]

Hi Stephen Cobeldick and thank you once more for responding!

I tired this code below which is the correct field name and it is still throwing an error!!! Please assist me!

thank you in advance!

 C{kk} = S.BeatGTruth; % !!! use an appropriate fieldname !!!
 
 

%%% ERROR

[Stephen23]

Unfortunately each .mat file contain a differently-named variable. In future I strongly recommend that each .mat file should contain exactly the same variable names, this makes processing them in a loop easier and more robust.

Here is a work-around for your example files:

F = {'Beat1GTruth.mat', 'Beat2GTruth.mat', 'Fight1GTruth.mat', 'Fight2GTruth.mat', 'Shoot1GTruth.mat', 'Shoot2GTruth.mat', 'Stab1GTruth.mat', 'Stab2GTruth.mat'};
N = numel(F);
C = cell(1,N);
for kk = 1:N
    S = load(F{kk}); % load into a structure
    C(kk) = struct2cell(S); % !!! assumes only ONE field per structure !!!
end
T = [C{:}]; % optional but recommended: concatenate into one non-scalar structure

You can access the data in the non-scalar structure T using indexing and fieldnames:

https://www.mathworks.com/help/matlab/matlab_prog/access-multiple-elements-of-a-nonscalar-struct-array.html

For example, the MCOS data for the first file:

>> T(1).MCOS
ans =
  3707764736
           2
           1
           1
           1
           5

[Matpar]

Hi Stephen Cobeldick and thank you for the advice I am grateful loads,

I am not sure how to do that but with trial research and my will I may get there, but i will welcome you teachings if you can demonstrate such with a link please!

In reference to your guidance,

Ok now this had no error running the operations.

I am seeing the S 1x1 struct variable in the workspace but there is only one field Stab2GTruth!!

Shouldn't I see the rest of the data file/field names from the other ,mat files loaded from the variable (F)!!???!!?? instead it is showing 8field with 1x1 groundTruth?!!!?!!

[Stephen23]

You do not appear to be running the complete code from my last comment.

Pease run the complete code that I gave, including the last line:

T = [C{:}];

T will then be a 1xN structure with two fields, it contains all of the data from all of your files.

[Matpar]

Hi Stephen Cobeldick,

I did see it and I ran it just as is!! that is what is confusing me!

I got to the step of training the cnn objectdetector but it came back with an error about the groundtruths not being in the right format!!

I am learning and it is fun! but not so much fun when I am stuck and not knowing nor understanding the full processes to move forward!

Please help!

and thank you in advance pal!