How to execute a matlab code for different files? - matlab

I have this matlab code who read and load my csv files
> `%% Initialize variables.
filename = 'C:\Users\loubn\Documents\MATLAB\test\fichier1.csv';
delimiter = ',';
to the end of the code
and it work perfectly , i want to execute this script for the others .csv files (fichier2,fichier3 ....... fichieri) on the test folder

You may simply store all the file names into a cell array and then use a for loop:
allFilenames = {'C:\...\file1.csv','C:\...\file2.csv','C:\...\file3.csv'};
for ii=1:length(allFilenames)
filename=allFilenames{ii};
% Do something with variable "filename"
end
Another option is to store them into a structure array (such as what the dir function provides).
testDir = 'C:\Users\...\test';
template = '*.csv';
allFiles = dir(fullfile(testDir,template));
% This will produce an array of structures with the file name in field "name"
for ii=1:length(allFiles)
%Combine directory and file name into an absolute path to the file
filename=fullfile(testDir,allFiles(ii).name);
% Then do something with variable "filename"
end

normally it should work direktly if you change the filename string.
filename = 'C:\Users\loubn\Documents\MATLAB\test\fichier2.csv'
Have you tried that already? Or is there some other kind of problem?

Related

how to load multiple files from directory into an array using matlab?

i have a directory that includes some .mat files , i want to load all these files into an array .
i tried something like this :;
x1=load('C:\Users\me\OneDrive\Desktop\project\a\first_file.mat')
x2=load('C:\Users\me\OneDrive\Desktop\project\a\second_file.mat')
... and so on for all the files in the directory , and at the end i want to have an array such that:
arr(1)=x1 ...
how can i access the directory and load all of the files at the same time into an array ?
ps: i tried using path before and dir but then i got this error :
error using eval , undefind function 'workspacefun' for input
arguments of type struct
thank you in advance.
The load function loads what variables are in the .mat file with their real names into the current workspace. If you assign x as an output for load, the variables names appear as fields of a struct named x. For example, if first.mat contains v1, then, x = load('first.mat') will result in a x = struct with fields: v1.
So, in your case, assuming that you are sure that each .mat file contains a single variable, you can write the following loop to load all .mat files into a cell array arr.
fds = fileDatastore('*.mat', 'ReadFcn', #load); % assume same folder
files = fds.Files;
for i = 1:length(files)
% convert one-field struct into array, store in "arr"
arr{i} = struct2array(load(files{i}));
end
And each arr{i} will now contain a variable, say vi, in lexicographic order. If the .mat file contains more than one variable, this code will break. If the files are in another folder, you can use their actual path and extension like this fileDatastore('path', 'ReadFcn', #load, 'FileExtensions','.mat').

Converting multiple .txt files to .mat in the same folder

I have many .txt files that contain n rows and 7 columns each delimited with whitespace. I want to convert each file to .mat file and save that in the same folder.
I tried this but it's not working:
files = dir('*.txt');
for file = files'
data=importdata(file.name);
save(file.name, 'data');
end
While this works for a single file, i want to do it programmably since the number of .txt files i have is very large:
data=importdata('myfile.txt');
save('myfile', 'data');
Thank you for your help
This should work
files = dir('*.txt');
for idx = 1:length(files)
file_name = files(idx).name;
fprintf("Processing File %s\n",file_name);
data=importdata(file_name);
[filepath,name,ext] = fileparts(fullfile(pwd,file_name));
save([name '.mat'],'data');
end
dir creates a stucture which you need to index through so we create the for loop to start at 1 and keep going until all the elements of dir have been processed.
Note in the code, I've also added a section to split the file name (e.g file1.txt) in to the file name and extension. This is so we only use the name part and not the extension when creating the mat file.
#scotty3785's answers worked well and also this worked for me in case somebody needs it:
files = dir('*.txt');
for i=1:length(files)
data=importdata(files(i).name);
save(erase(files(i).name,".txt"), 'data');
end

Reading a file from a different directory in matlab

My matlab function is in a folder that contains the main project and the other functions of the code. However, the data is stored in a folder withing the main one named "data" and inside the specific dataset that i want, for example "ded4" in this example. I can't figure out how to open the text file that I want without changing the file to the main folder. The code I have so far is:
function[Classify] = Classify(logDir)
%%%%logDir='ded014a04';
Directory = ['data/' logDir '/']
Filename = [logDir '-fixationsOffSet']
File_name = fullfile(Directory,Filename)
File = fopen(File_name,'r')
end
The code is in the 'dev' folder, I think my path is correct because when I do
open(File_name)
it opens.
Thanks for the help
If you want to open the file in the editor, use
open(File_name)
If you want to read data from the file, you can use
dlmread(File_name) % Read ASCII delimited file.
or
C = textscan(File,'FORMAT') % Read formatted data from text file or string.
or more low-level using fscanf, e.g., if the file contains three columns of integers you do the following: Read the values in column order, and transpose to match the appearance of the file: (from the help of fprintf)
fid = fopen('count.dat');
A = fscanf(fid,'%d',[3,inf])';
fclose(fid);

Find and replace text file Matlab

I'm writting a Matlab code that generates an array number and it should replace that each number in a text file (that already exists) and replace all instances with that. The number should be in string format. I've achieved this:
ita='"';
for i=1:size(z,2)
word_to_replace=input('Replace? ','s');
tik=input('Replacement? ','s');
coluna=input('Column? ');
files = dir('*.txt');
for i = 1:numel(files)
if ~files(i).isdir % make sure it is not a directory
contents = fileread(files(i).name);
fh = fopen(files(i).name,'w');
val=num2str(z(i,coluna));
word_replacement=strcat(tik,val,ita);
contents = regexprep(contents,'word_to_replace','word_replacement');
fprintf(fh,contents); % write "replaced" string to file
fclose(fh) % close out file
end
end
end
I want the code to open the file#1 ('file.txt'), find and replace all instances 'word_replacement' with 'word_to_replace' and save to the same file. The number of txt files is undefined, it could be 100 or 10000.
Many thanks in advance.
The problem with your code is the following statement:
contents = regexprep(contents,'word_to_replace','word_replacement');
You are using regular expressions to find any instances of word_to_replace in your text files and changing them to word_replacement. Looking at your code, it seems that these are both variables that contain strings. I'm assuming that you want the contents of the variables instead of the actual name of the variables.
As such, simply remove the quotations around the second and third parameters of regexprep and this should work.
In other words, do this:
contents = regexprep(contents, word_to_replace, word_replacement);

MATLAB - read files from directory?

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