I keep running across this error in my code:
Path = 'C:\Users\18606\OneDrive\Documents\Spheroids For Brandon\Spheroids\1-8WT';
Content = dir(Path);
SubFold = Content([Content.isdir]); % Keep only the directories
MyData = [];
for k = 3:length(SubFold)
F = fullfile(Path, SubFold(k).name);
fileID = fopen(F);
MyData{end+1} = fopen(fileID,'%s\n');
fclose(fileID);
Resulting in the error:
Error using fopen
Invalid filename (line 8)
The code is trying to iterate over multiple images in multiple subfolders of the main. The goal is to process the images with an edge detection algorithm for each file, but that's besides the point. Why would the program give an invalid file name when the path, content and subfolders are all specified in the code? Do the variables mentioned have anything to do with the error? Finally, is there a better way to open and read the images iteratively?
Reading in files sequentially is indeed usually done through looping over a dir() call, i.e. your strategy is valid. What's going wrong here, is that Path is a path to a directory, not a file. SubFold then are only directories as they are found on the Path. fullfile(Path, SubFold(k).name) finally creates a path to a subdirectory of Path. A subdirectory is not a file, thus fopen will tell you that it's an incorrect filename.
You'll probably need another dir() call, e.g. dir(F) to get all files on the path specified by F.
Related
I'm using MATLAB R2017a and I would like to create a new binary file within the folder the script is running from.
I am running matlab as administrator since otherwise it has no permissions to create a file. The following returns a legal fileID:
fileID = fopen('mat.bin','w');
but the file is created in c:\windows\system32.
I then tried the following to create the file within the folder I have the script in:
filePath=fullfile(mfilename('fullpath'), 'mat.bin');
fileID = fopen(filePath,'w');
but I'm getting an invalid fileId (equals to -1).
the variable filePath is equal in runtime to
'D:\Dropbox\Studies\CurrentSemester\ImageProcessing\Matlab
Exercies\Chapter1\Ex4\mat.bin'
which seems valid to me.
I'd appreciate help figuring out what to do
The problem is that mfilename returns the path including the file name (without the extension). From the documentation,
p = mfilename('fullpath') returns the full path and name of the file in which the call occurs, not including the filename extension.
To keep the path to the folder only, use fileparts, whose first output is precisely that. So, in your code, you should use
filePath = fullfile(fileparts(mfilename('fullpath')), 'mat.bin');
I'm trying to access images in a matlab interface
my code is as follows:
global im2 im
axes(handles.axes4);
[path1, user_cance]= imgetfile();
if user_cance
msgbox(sprintf('Error'), 'Error', 'Error');
return
end
srcFiles = dir('C:\Users\User\Desktop\images test\yale faces\yalefaces\..');
% yale faces is the database folder
for i = 1 : length(srcFiles)
file_name=dir(strcat('C:\Users\User\Desktop\images test\yale faces\yalefaces'));
im2=imread(strcat('C:\Users\User\Desktop\images test\yale faces\yalefaces',file_name(i).name));
%processing of read image
end
the issue is that when I run the code, it gives the following error:
Can't open file "C:\Users\User\Desktop\images test\yale faces\yalefaces" for
reading;
you may not have read permission.
Does anyone know how to solve this issue?
When you do a directory listing (without any wildcards) you are going to get the current directory '.' and parent directory as well '..'. You can't read these like files because they are directories. You will need to filter out the directories prior to trying to read them with imread.
files = dir('C:\Users\User\Desktop\images test\yale faces\yalefaces');
% Remove directories
files = files(~[files.isdir]);
As a side note, it is very hard to tell what your code is doing, but I'm pretty sure it doesn't do what you hope.
It seems like you want to get all images within the database. If that's so, you'll want to do something like.
folder = 'C:\Users\User\Desktop\images test\yale faces\yalefaces';
% Get a list of all files in this folder
files = dir(folder);
files = files(~[files.isdir]);
for k = 1:numel(files)
% Append the folder with the filename to get the path and load
im2 = imread(fullfile(folder, files(k).name));
end
I highly discourage using strcat to construct file paths particularly because it removes trailing/leading whitespace from each input which can corrupt a filename. fullfile was designed for exactly this so please use that.
I write code where I load a lot of project data. I want to keep my pathnames in the code relative to some location of this project on the disk, i.e. not having it configured or hard-coded.
Is there function in matlab to do some like this?
In python I would write:
ROOT = os.path.dirname(__file__)
The best way to do this is to combine fileparts with mfilename('fullpath'). (All examples assume the executing m-file containing these statements lives in /home/suever/code/stackoverflow.m)
mfiledir = fileparts(mfilename('fullpath'));
/home/suever/code
Then you can use fullfile to construct any paths you need from that. Now if you have a file (data.mat) stored in the same directory:
filename = fullfile(mfiledir, 'data.mat');
/home/suever/code/data.mat
Of if the file is actually in the parent directory.
filename = fullfile(mfiledir, '..', 'data.mat');
/home/suever/data.mat
If you want just the parent directory that an m-file is in, you can apply fileparts twice and only keep the second output.
[~, reldir] = fileparts(fileparts(mfilename('fullpath')));
code
I would recommend the use of full paths in the first examples as those are completely independent of the user's current working directory.
A better recipe to organize your code is to have a function like this:
function [ path ] = get_path()
path = [regexprep(mfilename('fullpath'), ['\' filesep '[\w\.]*$'],'') filesep];
end
You drop it inside +foo/get_path.m file and than call something like foo.get_path() that returns the path to +foo folder.
I'd like to remove '-2' from the filenames looking like this:
EID-NFBSS-2FE454B7-2_TD.eeg
EID-NFBSS-2FE454B7-2_TD.vhdr
EID-NFBSS-2FE454B7-2_TD.vmrk
EID-NFBSS-3B3BF9FA-2_BU.eeg
EID-NFBSS-2FE454B7-2_PO.txt
So as you may see the names of the files are different and there are different kind of extensions as well. All what I want to do is remove '-2' from all of the filenames. I was trying use this:
pattern = '-2';
replacement = '';
regexprep(filename,pattern,replacement)
and I got the results in the console, but after many attempts I have no idea how to 'say' to MATLAB switch the filnames in the same location.
#excaza hit it right on the money. You'll have to probe your desired directory for a list of files via dir, then loop through each filename and remove any occurrences of -2, then use movefile to rename the file, and delete to delete the old file.
Something like this comes to mind:
%// Get all files in this directory
d = fullfile('path', 'to', 'folder', 'here');
directory = dir(d);
%// For each file in this directory...
for ii = 1 : numel(directory)
%// Get the relative filename
name = directory(ii).name;
%// Replace any instances of -2 with nothing
name_after = regexprep(name, '-2', '');
%// If the string has changed after this...
if ~strcmpi(name, name_after)
%// Get the absolute path to both the original file and
%// the new file name
fullname = fullfile(directory, name);
fullname_after = fullfile(directory, name_after);
%// Create the new file
movefile(fullname, fullname_after);
%// Delete the old file
delete(fullname);
end
end
The logic behind this is quite simple. First, the string d determines the directory where you want to search for files. fullfile is used to construct your path by parts. The reason why this is important is because this allows the code to be platform agnostic. The delineation to separate between directories is different between operating systems. For example, in Windows the character is \ while on Mac OS and Linux, it's /. I don't know which platform you're running so fullfile is going to be useful here. Simply take each part of your directory and put them in as separate strings into fullfile.
Now, use dir to find all files in this directory of your choice. Replace the /path/to/folder/here with your desired path. Next, we iterate over all of the files. For each file, we get the relative filename. dir contains information about each file, and the field you want that is most important is the name attribute. However, this attribute is relative, which means that only the filename itself, without the full path to where this file is stored is given. After, we use regexprep as you have already done to replace any instances of -2 with nothing.
The next point is important. After we try and change the filename, if the file isn't the same, we need to create a new file by simply copying the old file to a new file of the changed name and we delete the old file. The function fullfile here helps establish absolute paths to where your file is located in the off-chance that are you running this script in a directory that doesn't include the files you're looking for.
We use fullfile to find the absolute paths to both the old and new file, use movefile to create the new file and delete to delete the old file.
I wish to read files from a directory and iteratively perform an operation on each file. This operation does not require altering the file.
I understand that I should use a for loop for this. Thus far I have tried:
FILES = ls('path\to\folder');
for i = 1:size(FILES, 1);
STRU = pdbread(FILES{i});
end
The error returned here suggests to me, a novice, that listing a directory with ls() does not assign the contents to a data structure.
Secondly I tried creating a file containing on each line a path to a file, e.g.,
C:\Documents and Settings\My Documents\MATLAB\asd.pdb
C:\Documents and Settings\My Documents\MATLAB\asd.pdb
I then read this file using the following code:
fid = fopen('paths_to_files.txt');
FILES = textscan(fid, '%s');
FILES = FILES{1};
fclose(fid);
This code reads the file but creates a newline where a space exists in the pathway, i.e.
'C:\Documents'
'and'
'Setting\My'
'Documents\MATLAB\asd.pdb'
Ultimately, I then intended to use the for loop
for i = 1:size(FILES, 1)
PDB = pdbread(char(FILES{i}));
to read each file but pdbread() throws an error proclaiming that the file is of incorrect format or does not exist.
Is this due to the newline separation of paths when the pathway file is read in?
Any help or suggestions greatly apppreciated.
Thanks,
S :-)
First Get a list of all files matching your criteria:
( in this case pdb files in C:\My Documents\MATLAB )
matfiles = dir(fullfile('C:', 'My Documents', 'MATLAB', '*.pdb'))
Then read in a file as follows:
( Here i can vary from 1 to the number of files )
data = load(matfiles(i).name)
Repeat this until you have read all your files.
A simpler alternative if you can rename your files is as follows:-
First save the reqd. files as 1.pdb, 2.pdb, 3.pdb,... etc.
Then the code to read them iteratively in Matlab is as follows:
for i = 1:n
str = strcat('C:\My Documents\MATLAB', int2str(i),'.pdb');
data = load(matfiles(i).name);
% use our logic here
% before proceeding to the next file
end
I copy this from yahoo answers! It worked for me
% copy-paste the following into your command window or your function
% first, you have to find the folder
folder = uigetdir; % check the help for uigetdir to see how to specify a starting path, which makes your life easier
% get the names of all files. dirListing is a struct array.
dirListing = dir(folder);
% loop through the files and open. Note that dir also lists the directories, so you have to check for them.
for d = 1:length(dirListing)
if ~dirListing(1).isdir
fileName = fullfile(folder,dirListing(d).name); % use full path because the folder may not be the active path
% open your file here
fopen(fileName)
% do something
end % if-clause
end % for-loop