How to apply multiple parameters function on all the matrices in the folder?

A=randperm(16);
A=reshape(A,4,4);
function [B]=fun(A,a,b,c)
B= a.*A+b.*A+c.*A
end
vals = [1, 2,3
6,1,4
7,3,5] ; 
[m,n]  =size(vals) ; 
B = zeros(4,4,m) ; 
for i = 1:m
    B(:,:,i)=fun(A,vals(i,1),vals(i,2),vals(i,3)) ; 
end

The above code works perfectly for single A,

I want to apply the above on set of matrices stored in a foder

l have tried the following but it stored result only for single A

srcFiles = dir(...);  % the folder in which matrices exists
for i = 1 : length(srcFiles)
    filename = strcat('...',srcFiles(i).name);
    I = %reading(filename);
    vals = [1, 2,3
6,1,4
7,3,5] ; 
[m,n]  =size(vals) ; 
B = zeros(4,4,m) ; 
for j = 1:m
    B(:,:,j)=fun(I,vals(j,1),vals(j,2),vals(j,3)) ; 
    % and want to save all the new B's .
end
end

[Awais Saeed]

Do not know what your actual problem is but your loop structure does not seem OK. Let's say you have 2 files. You read file1 and after some operations you get 3D B array. But when you do the same process again for file2, you are overwriting B array. Do not you want B array for all files?

[Ammy]

In other words, I want to find the following for 100 A's that are stored in a folder

A=randperm(16);
A=reshape(A,4,4);
function [B]=fun(A,a,b,c)
B= a.*A+b.*A+c.*A
end
vals = [1, 2,3
6,1,4
7,3,5] ; 
[m,n]  =size(vals) ; 
B = zeros(4,4,m) ; 
for i = 1:m
    B(:,:,i)=fun(A,vals(i,1),vals(i,2),vals(i,3)) ; 
end

Yes, of course, I need B corresponding to every A in the folder.

[Awais Saeed]

To store results for all matrices, use cell arrays. Something like this

for j = 1:1:m
    B = fun(FileLoaded,vals(j,1),vals(j,2),vals(j,3));
    Results{i,j} = B;
end

Answer 1

[Awais Saeed]

1. Read your .mat files
2. Loop through them and find B
3. Store that B array to a cell

% path to the folder that contains .mat files
Folder_location = 'C:\Users\Awais\Documents\MATLAB';
% Get paths of all files in that folder
Files = fullfile(Folder_location, '*.mat');
Files = dir(Files);
% display File details
struct2table(Files)
for fileNum = 1:1:length(Files)
    % get name of file
    fileName = Files(fileNum).name;
    % load file. It will be your matrix but in a struct
    FileLoaded = load(fileName);
    % Extract matrix from struct
    A = cell2mat(struct2cell(FileLoaded))
    fprintf('Loaded file # %d, name = %s \n',fileNum, fileName)
    vals = [1 2 3; 6 1 4; 7 3 5];
    [m ,n] = size(vals);
    for j = 1:1:m
        B = Myfun(A,vals(j,1),vals(j,2),vals(j,3));
        Results{fileNum,j} = B;
    end
    
end

function [B] = Myfun(A,a,b,c)

% A is a matrix here
B = a.*A + b.*A + c.*A

end

[Ammy]

Thank you very much. If I have A as image then I got the error

Undefined function 'struct2table' for input arguments of type 'struct'.

Is there way to resolve this , in other words if there are images in a folder then?

[Awais Saeed]

dir() returns a struct. I used struct2table() to display what you got from dir() (look in the attached image). Secondly, I am not well aware how to deal with images and I cannot help you with that but you can get the idea how to load an image from the snippet provided below:

% path to the folder that contains .png files
Folder_location = 'C:\Users\Awais\Documents\MATLAB';
% Get paths of all files in that folder
Files = fullfile(Folder_location, '*.png');
Files = dir(Files);
% display File details
struct2table(Files)
for fileNum = 1:1:length(Files)
    fileName = Files(fileNum).name;
    fprintf('Loaded file # %d, name = %s \n',fileNum, fileName)
    % read image
    FileLoaded = imread(fileName);
    fprintf('Size of %s is: ', fileName)
    size(FileLoaded)
    fprintf('\n')
end

Also you are using

A=randperm(16);
A=reshape(A,4,4);

in your question. However, converting an image to matrix will give you a huge matrix or most probably a multi-dimensional array which is still bigger than 4x4 matrix (look the size of images I got in the attached image).