uigetfile, load m-file variables into workspace

37 views (last 30 days)
Hello,
I've been trying to load variables from a *.m file into my workspace with the following code provided by Support Team by clicking the pushbutton on my gui.
function profil_laden_Callback(hObject, eventdata, handles)
filename = uigetfile('*.mat');
command = sprintf('load(''%s'')', filename);
evalin('base', command);
But i get the error:
Error using load
Number of columns on line 3 of ASCII file Eingabe.m must be the same as previous lines.
My m file is a editable file for users, so they can put their values in. It is full of comments.
Thanks
  1 Comment
Stephen23
Stephen23 on 17 Dec 2016
Edited: Stephen23 on 17 Dec 2016
evalin is the worst way of passing data between workspaces:
and evalin, like eval, is slow and buggy:
Much faster and more robust would be to load the data into a structure, and and use nested functions to pass the data between the workspaces.

Sign in to comment.

Accepted Answer

Image Analyst
Image Analyst on 17 Dec 2016
Edited: Image Analyst on 2 Jan 2017
Do it like this instead
[baseFileName, folder] = uigetfile('*.mat');
fullFileName = fullfile(folder, baseFileName);
if exist(fullFileName, 'file')
% Normal situation - they picked an existing file.
storedStructure = load(fullFileName);
% Now do something with storedStructure, like extract fields into new variables or whatever you want.
else
% Error: Would only get here if they typed in a name of a non-existant file
% instead of picking one from the folder.
warningMessage = sprintf('Warning: mat file does not exist:\n%s', fullFileName);
uiwait(errordlg(warningMessage));
return;
end
Note that the variables in a callback function are local. If you want them to be visible (in scope) outside that function you have to do something to make it so. For that, see the FAQ for a variety of ways: http://matlab.wikia.com/wiki/FAQ#How_can_I_share_data_between_callback_functions_in_my_GUI.28s.29.3F
  2 Comments
Image Analyst
Image Analyst on 2 Jan 2017
Sorry - I had it reversed. Put the filename first and the folder second:
[baseFileName, folder] = uigetfile('*.mat');
I'll correct it above too.

Sign in to comment.

More Answers (1)

Les Beckham
Les Beckham on 17 Dec 2016
Edited: Les Beckham on 17 Dec 2016
.m files are used to store Matlab code - NOT data.
You can create data in your workspace by running an m file but not by loading it.
If you are just creating a text file with manually editable data in it, you should not use the .m (or .mat) extension -- it will just cause confusion. Perhaps just use .txt (or .csv if you are using comma delimiters).
You need to be careful when creating text data files so that each row has the same number of entries or it can get tricky to read the data. You will get errors like the one in your question.
Reading a text file is best done with importdata or similar, not load.
Please clarify what type of file you are really working with (provide a short example or the real file).
  2 Comments
Jan w
Jan w on 2 Jan 2017
Since the user uses matlab I let them edit an *.m file that creates a *.mat file that then is used for further operations.

Sign in to comment.

Categories

Find more on Migrate GUIDE Apps in Help Center and File Exchange

Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by