How to use the load function to open and read a .txt file?

I have a macbook air and I made a .txt file using Word. I imported it into Matlab and now I want to load it using the load function but Matlab says

"Error using load

Unable to read file 'FILENAME'. No such file or directory."

I imported the file and it is in my workspace so why is the load function now working?

[Image Analyst]

Why not use fileread(), importdata(), or dlmread() or something? Also, you need to get the filename correct, which, from the error, we can tell that you DON'T.

[Sarah Abraham]

Professor wants us to use load. I have the file in workspace as BME330HW2 and it was uploaded from BME330HW2.txt which i tried both names when I used load

[Walter Roberson]

load BME330HW2.txt

[Image Analyst]

Try this:

fullFileName = fullfile(pwd, 'BME330HW2.txt');
if ~isfile(fullFileName)
    warningMessage = sprintf('File not found:\n', fullFileName)
    uiwait(errordlg(warningMessage))
    return;
end
s = load(fullFileName)

What do you see?

If you "imported the file and it's in your workspace", then you don't need load - it's already been loaded, and it's in your workspace as a variable. Show a screenshot of your workspace.

[Sarah Abraham]

[Sarah Abraham]

I rather not use import at all and just use load, if possible

[Giuseppe Inghilterra]

Can you attach .txt file?

I tried on my own and load function works. (my .txt file contains only numbers).

load mytxt.txt

If I don't specify extension file .txt I get your same error:

"Error using load

Unable to read file 'mytxt'. No such file or directory."

[Sarah Abraham]

Did you first import the .txt file?

[Sarah Abraham]

[Giuseppe Inghilterra]

I'm seeing your screenshot now. HW2 is in your workspace variable, thus you have already loaded into it.

There is no need to load it "again". It is in your workspace, so you can manipulate table data HW2 to do your math.

[Sarah Abraham]

Okay but if I do not import the file into the workspace the load function still does not work. How do I use the load function without importing it into my workspace?

[Giuseppe Inghilterra]

Are you sure that your .txt file is in your working directory?

[Star Strider]

The file must be in your MATLAB search path.

See: What Is the MATLAB Search Path? for details.

[Sarah Abraham]

How do I open a file in a path?

[Walter Roberson]

Remember to give the txt extension

Also having a space between a function name and the ( can cause problems sometimes.

[Sarah Abraham]

yay!!!!!!!!!!

[Giuseppe Inghilterra]

Try:

load('C:\Users\sarahabraham\Desktop\HW2.txt')

and of course HW2.txt file is in your desktop.

Sorry, I see that you have already solved your problem ;)

[Walter Roberson]

A filename of the form /Users/NAME/desktop is most likely a Mac, in which case \ between path components would not work, and C: drive would not work.

Interestingly, on Windows, you can use / in paths -- so if such a file existed, 'C:/Users/sarahabraham/Desktop/HW2' would be valid. This suggests that for portability, if you do not code in terms of fullfile(), that you are better off coding in terms of /

Answer 1

[Image Analyst]

Sarah, The problem was that the file was not in the same folder as your script (if you were running an m-file) or your current folder (if you were running from the command line). So you need to construct the full filename accurately, using the full folder of where it lives, plus the extension of the file. Try this more robust code:

folder = 'C:\Users\sarahabraham\Desktop\';
fullFileName = fullfile(folder, 'BME330HW2.txt');
if ~isfile(fullFileName)
	warningMessage = sprintf('File not found:\n%s\nWhen the next dialog box comes up, please locate it.', fullFileName)
	uiwait(errordlg(warningMessage))
	% Have user browse for a file, from a specified "starting folder."
	% For convenience in browsing, set a starting folder from which to browse.
	startingFolder = pwd;  % or 'C:\wherever';
	if ~exist(startingFolder, 'dir')
		% If that folder doesn't exist, just start in the current folder.
		startingFolder = pwd;
	end
	% Get the name of the file that the user wants to use.
	defaultFileName = fullfile(startingFolder, '*.*'); % Can use *.txt if you want only text files to show up.
	[baseFileName, folder] = uigetfile(defaultFileName, 'Select a file');
	if baseFileName == 0
		% User clicked the Cancel button.
		return;
	end
	fullFileName = fullfile(folder, baseFileName)
end
s = load(fullFileName)

Paste this into a script and run it. Now, no matter where the script lives, it will first try to try to find the file called

'C:\Users\sarahabraham\Desktop\BME330HW2.txt'  % Change to different filename, if desired.

If that file does not exist, then it will bring up a dialog box asking the user to find the file she wants to read in.

Hope that helps.