MATLAB: Finding file in a before selected folder

csvreaddirectoryfileguimatlab guipush buttonuser interface

Hello everyone! I am new to GUI in MATLAB and I need to write an analysis user interface. I am just starting out and the first step for the GUI is to let the user select the directory that contains the data files. This is the code so far:

    % % --- Executes on button press in ChooseFolder.
function ChooseFolder_Callback(hObject, eventdata, handles)
% hObject    handle to ChooseFolder (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

folder = uigetdir('Search Folder Containing Data Files');
if isequal (folder, 0);
    set(handles.DisplayFolderName, 'String', 'No folder selected');
    set(handles.FileInputString, 'enable', 'off');
else
[~, name] = fileparts(folder); 
textLabel = sprintf('Selected folder is %s', name);
set(handles.DisplayFolderName, 'String', textLabel);
filePattern = fullfile(folder, '*.csv');
allfiles = dir(filePattern);
for k = 1 : length(allfiles);
    baseFileName = allfiles(k).name;
end
end

Now I want to add a Edit Text and Push Button. The Edit Text allows the user to enter the filename (for example): ID0123. Then, the Push Button can be pressed and MATLAB will look for this file in the before chosen directory. I have tried this:

      %  --- Executes on button press in findfile1.
function findfile1_Callback(hObject, eventdata, handles)
% hObject    handle to findfile1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
filename = get(handles.edit1, 'String');
if exist (name, filename) 
    csvread(filename);
else 
    warningMessage = sprintf ('Warning: file does not exist:\n%s' , filename);
    uiwait(msgbox(warningMessage));
   end

But this does not do anything. Can anyone please help me with this issue?

Would be very much appreciated

Best Answer

I looked at the exist help, but could not find any syntax that matches how you are using it. Probably you should read the documentation and use one of the supported syntaxes, e.g.:

if 2==exist(filename,'file')

Also the line:

csvread(filename);

reads some data and then discards it immediately.

Related Solutions

MATLAB: Search for a file using edit text with a part of the file name

You could experiment with dir:

str = '0283';
fmt = sprintf('*%s*.csv',str);
S = dir(fmt);
filename = S.name

Or perhaps:

fmt = sprint('ID%s15sec.csv',str);

One flexible solution would be to let the user define as much of the filename as they want, find all matches, and then filter for only those that match the required filename pattern:

str = '0283';
S = dir(sprintf('*%s*',str));
N = {S(~[S.isdir]).name};
idx = ~cellfun('isempty',regexp(N,'^ID\d{4}15sec\.csv$'));
filename = N{idx}

Note:

you will need to add the filepath.
you will need to add checks to see if zero/multiple files match what the user gives. If you omit this it will only cause problems later!

As an alternative, you could simply use uigetfile.

MATLAB: How to use path- and filename from GUI in matlab script

Thore - rather than using global variables, try changing your script into a function which accepts the path to and name of some file. For example,

 function FixedLineString(filename, pathname)
 if isempty(filename) || isempty(pathname) 
     [filename,pathname] = uigetfile('*.DAT','Select the .DAT file');
 end
 % etc.

The above code allows for the filename and pathname to be optional so that if at least one is not provided, then the user is prompted to choose a file.

Now in your GUI, you would save the path to and the name of the file to your handles structure as

 function pushbutton1_Callback(hObject, eventdata, handles)
 [filename, pathname] = uigetfile('*.DAT');
 set(handles.text3, 'String', filename);
 handles.filename = filename;
 handles.pathname = pathname;
 guidata(hObject,handles);

Then, when you want to pass the path and name of the file to your (new) function, you would do

 function Start_button_Callback(hObject, eventdata, handles)
 pathname = [];
 filename = [];
 if isfield(handles,'pathname') && isfield(handles,'filename')
    pathname = handles.pathname;
    filename = handles.filename;
 end
 FixedLineString(pathname,filename);

In the above, we check to make sure that handles has fields for both pathname and filename before trying to access either. If both exist, then we pass both to your function. Else we pass empty input parameters which will cause your function to request the the user choose a file.

Try the above and see what happens!

As an aside, I noticed that in your callbacks you typically did

 handles = guidata(hObject);

This is unnecessary as the third input to all callbacks is already the handles structure and so calling the above just duplicates what already has been done. Also, you only need to call

 uidata(hObject, handles);

if you have updated the handles structure as we did in pushbutton1_Callback. Otherwise, there is no need to call it.

Best Answer

Related Solutions

MATLAB: Search for a file using edit text with a part of the file name

MATLAB: How to use path- and filename from GUI in matlab script

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