image a set of matrix variables after loading them in

Hello. I am trying to load a set of files in a folder into matlab, and then perform an operation on each of them. From the MATLAB FAQ I have the following code:

clear all; close all; 
% Specify the folder where the files live.
myFolder = 'path for folder';
% Check to make sure that folder actually exists.  Warn user if it doesn't.
if ~isfolder(myFolder)
    errorMessage = sprintf('Error: The following folder does not exist:\n%s\nPlease specify a new folder.', myFolder);
    uiwait(warndlg(errorMessage));
    myFolder = uigetdir(); % Ask for a new one.
    if myFolder == 0
         % User clicked Cancel
         return;
    end
end
% Get a list of all files in the folder with the desired file name pattern.
filePattern = fullfile(myFolder, '*.csv'); % Change to whatever pattern you need.
theFiles = dir(filePattern);
for k = 1 : length(theFiles)
    baseFileName = theFiles(k).name;
    fullFileName = fullfile(theFiles(k).folder, baseFileName);
    fprintf(1, 'Now reading %s\n', fullFileName);
    
    load(fullFileName);
    readmatrix(fullFileName);
end

When I run this it then loads all the files that are csv files from the folder into my matlap workspace, which is what I want. However, I need a way to perform an operation on all of them (in this case to image each file), without having to type out every file name. Is there an easy way to do this? I have tried adding in image(fullFileName) but this does not work as the image command must refer to a specific variable. Any help much appreciated!!

[Stephen23]

Original question on 16th September 2020 at 18:20, retrieved from Google Cache:

"image a set of matrix variables after loading them in"

Hello. I am trying to load a set of files in a folder into matlab, and then perform an operation on each of them. From the MATLAB FAQ I have the following code:

clear all; close all; 
% Specify the folder where the files live.
myFolder = 'path for folder';
% Check to make sure that folder actually exists.  Warn user if it doesn't.
if ~isfolder(myFolder)
    errorMessage = sprintf('Error: The following folder does not exist:\n%s\nPlease specify a new folder.', myFolder);
    uiwait(warndlg(errorMessage));
    myFolder = uigetdir(); % Ask for a new one.
    if myFolder == 0
         % User clicked Cancel
         return;
    end
end
% Get a list of all files in the folder with the desired file name pattern.
filePattern = fullfile(myFolder, '*.csv'); % Change to whatever pattern you need.
theFiles = dir(filePattern);
for k = 1 : length(theFiles)
    baseFileName = theFiles(k).name;
    fullFileName = fullfile(theFiles(k).folder, baseFileName);
    fprintf(1, 'Now reading %s\n', fullFileName);
    
    load(fullFileName);
    readmatrix(fullFileName);
end

When I run this it then loads all the files that are csv files from the folder into my matlap workspace, which is what I want. However, I need a way to perform an operation on all of them (in this case to image each file), without having to type out every file name. Is there an easy way to do this? I have tried adding in image(fullFileName) but this does not work as the image command must refer to a specific variable. Any help much appreciated!!

[Rik]

@Stephen: I replaced the /save/ command from the WBM url with the actual date. If you replace it with /web/2/ the WBM will load the capture closest to 2500/01/01 00:00, so that should also work.

@OP: why did you edit away your question? You received an answer. This is all a waste of time, as the value of the answer is greatly reduces without the question, and future people will require time as well to get this same question answered.

[Rik]

What did you expect? Free private consultation? How else would it be possible to get help?

Since Stephen made a capture to the wayback machine, it is not possible to get your question offline. If you didn't want your question in public you shouldn't have posted it. You agreed to the terms and conditions.

[Rik]

How is this a privacy violation? You have the option to delete your question until there is an answer. After that you can only delete your question if the answer is deleted first. The system works this way to discourage abuse by people who want free help, but don't want to allow others to benefit.

Why do you want to remove your question? 'Just because you feel like it' seems a bit weak as a reason. You may not have a reason to leave it up, but the value of an answer is tied to the question. Without it the answer is much less helpful.

[Rik]

You can change your username and ask Stephen to edit away your name in his post. That second part is something I will leave to him, as I don't feel I have the right to be forcing that decision on him.

[Joe Joe]

Please remove my name from these comments.

[Rik]

This consistent deletion of things you posted is not convincing me of your good intentions.

[Joe Joe]

My only intention is to remove my name from this post, I fail to see why this is an issue. If the intent is to provide a question and an answer I have no issue with that as long as my name is not on the post. In fact I wouldn't mind re-adding the original question, as long as my name is removed.

[Adam Danz]

On one hand, it's fair to ask that your identify is protected and you did the right thing to change your profile name so that it's protected in the future.

On the other hand, many people use this forum to cheat on homework and assessments and they put themselves in that position when they are caught (I'm not assuming this is or is not the case with your question). I'm sure some people get free help in this forum and then claim the solutions to be their own, perhaps in patents, commercial products, graduate dissertations, without ever given credit to the actual authors of their work. Some people are embarrassed by mistakes but they shouldn't be. A big chunk of all questions in this forum are the result of a mistake and future visitors who learn from such threads have also made the same mistake so you've helped them, indirectly.

Private consultants are (or should be) obliged to protect your identify so if that's important to people, they should seek private consultation which usually costs a pretty penny. But this forum is largely fueled by unpaid volunteers and a major motivation to invest an hour or more into helping a stranger is knowing that it will potentially help many others in the future; some questions that are years old still get tens or hundreds of views a month.

Having said that, the content of a question/comment matters, not the name. But holding cheaters and intellectual thieves accountable also matters (again, I'm not classifying you). This is why some people may have problems with removing the OP's name after giving them a solution. Fortunately for you, your last name currently only exists once in this thread.

[Joe Joe]

Adam that is a good point, I hadn't thought of that. I have no way to prove this of course but it wasn't for a test or anything of the sort, and I have no reason why I should neccesarily need my name to be removed. I just think it is good policy to avoid having ones name on the internet when at all possible. As for holding intellectual thieves accountable, I can't disprove this either, although I doubt the value of a 1 line statement is all that much. I completely recognize I shouldn't have made this post if I didn't want my name on it, but in the moment I just assumed I could delete the post much like many other forms of "social media". This was, obviously, an incorrect assumption. I would hope that given that this is my first question, and in the spirit of encouraging a newcomer like me to continue participating in mathworks answers (hopefully being able to give my own advice once I understand Matlab better!) that it wouldn't be too big of a deal to remove my name. I'm open to anything in terms of leaving materiel up, me reposting the original comment, whatever. I think this should maybe speak a bit towards the fact that I am not doing anything wrong or cheating on anything, because of course if I were then why would I want my profile, which is linked to my email, to be associated with the post. Anyway let me know what you think and I appreciate the well thought out response.

[Adam Danz]

That's fair and reasonable and there are many users who don't use their real or full names (even MVPs) perhaps for similar reasons. We don't edit others' comments/answers/questions except to fix code formatting or typos so it's not my call.

BTW, your profile may be linked to your email but your current settings make that private to people outside of MathWorks. I don't have access to it.

[Joe Joe]

Adam, I see. Thank you for your help. Are there any steps I can take to get in contact with the MVPs directly rather than commenting on this post? Or are there any steps I can take to convince the various MVPs who posted my name to remove it? I am kind of lost on how to proceed with this, as I am unable to get a response from Stephen.

[Adam Danz]

If the user hasn't made their email link public on their profile, they likely don't want to be contacted by community members outside of the forum. I include mine mainly for support of my files on the file exchange. Maybe restoring the deleted content would be the start of a compromise; I can understand their frustration with that.

[Joe Joe]

Adam, I have restored the deleted content (at least all related to the question, I deleted the old comments I had that were asking to remove my name earlier, just because they weren't pertinent to the question, I don't know if there is a way to restore these or not, or if they would be worth restoring). Is there anyway I can get the attention of the MVPs who mentioned my name? Because as far as I can tell unless they subscribed to get emails about this question then there is no way for them to notice my request to have my name removed. I have tried flagging their comments but either this doesn't notify them or just made them upset. Or is there a way that you as an MVP could contact them?

edit: the reason I want to contact them is just so I can explain such as how I have done with you why I want my name removed, and see if there's a compromise that works.

Answer 1

[Stephen23]

Do not use load. Assign the imported data to an array, e.g.:

theFiles(k).data = readmatrix(fullFileName);

Now all of your imported data will be in the structure theFiles, which you can easily access using indexing:

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

[Stephen23]

"Is there a way to display each image from the image array at once?"

If you really want to you could create an array of figures and iterate over them, or use subplot, or create a video sequence, or something like that. I doubt that it would be very convenient, informative, or useful though.

"Or to save each image in the image array to my computer?"O

Of course, you can use imwrite.

"It seems to be only displaying the last image."

As you do not show your code, I have no idea how you are displaying these images. If you are displaying them in a loop, then quite likely on each loop iteration it will update the displayed image with the current image: all of them get get displayed, but only the last one will remain after the loop.

[Rik]

Now deleted comment:

Joe Joe on 16 Sep 2020 at 19:35

Thank you very much! This seems to be working, and I can use the arrayfun function to create an image array of all the data. Is there a way to display each image from the image array at once? Or to save each image in the image array to my computer? It seems to be only displaying the last image.