How to change directory in a for loop

Hey Guys, I have a .mat file where I have written all the directories I will use. Lets say one of the directory is 'C:\Users\md\Desktop\A_I_001'. I want to make this directory changed in each iteration. so, the 'j' value will change in each time. How I can do that? Thanks in advance.

load tmp.mat; j='directory'; a = j; A =dir( fullfile(a, '*.png') );

Answer 1

[per isakson]

Load the mat-file content to a variable

    S = load('tmp.mat');

Inspect S to learn how the folder names are stored. I can only guess and assumes that in the mat-file each folder name is in one string variable. If so this loop should work

    for folder_name = transpose( fieldnames( S ) )
        A = dir( fullfile( S.(folder_name{:}), '*.png' );
        ...
        ...    
    end

[Md]

folder names are stored like this: 'C:\Users\md\Desktop\A_I_001' 'C:\Users\md\Desktop\A_J_001'

[per isakson]

Yes, but those are the string values. There must be variable names of some kind! Run

    S = load('tmp.mat')

and tell me what appears in the command window. Or run

    clear
    load('tmp.mat')
    whos

[Md]

Hi, Thank you for your answer This is the output that I can see

 Name      Size            Bytes  Class    Attributes

tmp       1x1               300  cell

[per isakson]

tmp is a scalar, 1x1. What does

    tmp{:}

show? And

    S = load('tmp.mat')

?

Search a way to display the folder names in the command window and show the commands needed.