How can read multiple files in from a directory using matlab? Can someone please help correct my code below:
files =dir(fullfile(directory_path,'*.dat'));
numfiles = length('*.dat');
mydat = cell(1, numfiles);
for k = 1:numfiles
mydata{k} = fopen([directory_path,files(k).name]);
values=textscan(mydata{k},'%s','delimiter','\n');
fclose(fid);
%fprintf(values)
....do something with values.....
end
.dat files are just many rows and single column of strings that need to be read in a loop and processed further.
Thanks
fopen gives file pointer, which you save to mydata{k}, and try to release by fclose(fid). There is no fid, so it doesn't work.
What you should do is replace mydata{k} with fid. And probably values by mydata{k}.
The other bug is in numfiles = .... You will always have numfiles = 5, as there are 5 characters in the '*.dat'.
numfiles = length(files);
would be better, although you would also count directories. Check one of the other questions how to solve this.
Thanks Zizy Archer.
I solved the problem this way:
files =dir(fullfile(directory_path,'*.dat'));
numfiles = length(files);
for k = 1:numfiles
textFileName = [directory_path,files(k).name]
fid = fopen(textFileName, 'r');
textData = textscan(fid,'%s','delimiter','\n');
fclose(fid);
data = textData{:,1}
end
Related
I have multiple files that I want to open using fopen. The files have a similar pattern, I have tried to use a for loop as follows, but it does not work. Any ideas how to open each file. Thanks in advance.
for ii = 0:12
file = fprintf('population_%d.dat', ii); % -----> File names
generations_fid = fopen(file); % Question ???
matrix = {};
while ~feof(generations_fid)
generations = cell2mat(textscan(generations_fid, repmat('%f', 1, (3))));
if isempty(generations)
fgetl(generations_fid);
else
matrix{end+1} = generations;
end
end
end
You want to be using sprintf to dynamically generate the file name, not fprintf.
file = sprintf('population_%d.dat', ii);
It's also good practice to open your file with the required permissions. In your case, it looks like you're reading, so you should use
generations_fid = fopen(file, 'r');
I want to read all wav files containing in a folder, for each file I perform a function.
The result of this function is a number. I want save several results in a file txt.
This is my code:
dirMask = 'folder\*.wav';
wavRoot = fileparts(dirMask);
Files=dir(dirMask);
x = [];
for k=1:length(Files)
FileNames = fullfile(wavRoot, Files(k).name)
nomi=FileNames;
[s,fs] = audioread(FileNames);
a = function(s, fs);
x=a;
end
fid = fopen('file.txt','wt');
fprintf(fid,'%f\n',x);
fclose(fid);
This code doesn't work. How can I do this?
I rearranged things a bit. I wasn't entirely positive of the original intent but I think this is what you were trying to achieve:
dirMask = 'folder\*.wav';
Files = dir(dirMask);
fid = fopen('file.txt','wt');
for k=1:length(Files)
FileName = [ Files(k).folder '\' Files(k).name ]
[s,fs] = audioread(FileName);
% functions named function is a bad idea as it is keyword protected
x = myFunction(s,fs);
fprintf(fid,'%f\n',x);
end
fclose(fid);
I have boatloads of tab delimited textfiles that contain numerical data in 1000x2 format.
They're named file00001.txt - file10000.txt
I would like to write a script to load each of these files and make a variable containing ONLY the 400th row of the 2nd column of each of these files.
After that I'm going to try and plot a graph with the data I collected - but that's not important here.
I would be very grateful for your help.
Edit -
My most recent endeavour is:
numfiles = 10;
mydata = cell(1, numfiles);
for k = 1:numfiles
myfilename = sprintf('DM0000%d.txt', k);
mydata{k} = importdata(myfilename);
end
I'm running into a few problems -
1) if numfiles is >9, the 10th file data entry in the mydata variable comes up as []. This may have something to do with the naming method of my files? They're named in this fashion:
DM00000 ...DM00009, DM00010, DM00011, etc.
2) Also this is pretty slow to load, someone said using fopen, if so where should I put it in and how?
I'm guessing it'd be somewhere along the lines of fopen('filename', 'r')?
Based on your edit, this is what I'd recommend:
numfiles = 10;
row = 400;
column = 2;
data = zeros(1, numfiles);
for k = 1:numfiles
filename = sprintf('DM%05d.txt', k);
fid = fopen(filename,'r');
tempdata = textscan(fid, '%f%f');
fclose(fid);
data(k) = tempdata{column}(row);
end
I've updated the formatspec in sprintf to create the filenames correctly (you were missing the padding with zeros). I'm using textscan to import the data as doubles (change the %f to something else if required - check out the formatspec documentation). I also changed data to be a matrix rather than a cell array. You mentioned that you'd want to plot the data, so it'll be easier if it's a matrix and I couldn't see any need to use a cell array here.
I have 100 .dat files in a folder. Is it possible to read all the files at once with MATLAB and do average of the 5th column of those 100 files? Here is a sample of one of the .dat files.
Here is some code to get you started:
%# get list of 100 .dat files
pathToFolder = '.';
files = dir( fullfile(pathToFolder,'*.dat') );
%# read all files
data = cell(numel(files),1);
for i=1:numel(files)
fid = fopen(fullfile(pathToFolder,files(i).name), 'rt');
H = textscan(fid, '%s', 4, 'Delimiter','\n');
C = textscan(fid, repmat('%f ',1,8), 'Delimiter',' ', ...
'MultipleDelimsAsOne',true, 'CollectOutput',true);
fclose(fid);
H = H{1}; C = C{1};
%# store numeric data and ignore the header lines
data{i} = C;
end
%# we assume all tables have the same size
data = cat(3,data{:});
mn = mean(data(:,5,:),3) %# mean of 5th col across 100 files
Take a look # this http://www.mathworks.com/matlabcentral/newsreader/view_thread/161967
youre entire question is answered here. And youre answer is an FAQ # matlab
http://matlab.wikia.com/wiki/FAQ
Good luck!
I want to read in a text file that contains some strings but mostly numbers. I want to be able to ignore the strings and only look at the numbers. I want to plot those values on a 3D plane. The data looks like this:
Tech4:<152.266724,173.189377,27.995975>
<117.880638,156.116531,27.999983>
<129.849899,59.195660,27.999983>
<249.321121,60.605404,27.999983>
<224.120361,139.072739,28.000668>
<171.188950,143.490921,56.933430>
<171.188950,143.490921,83.548088>
<171.188950,143.490921,27.999985>
I believe to read in a file is just:
File = textread('testFile.txt');
How can I only look at those values and then plot it.
Thanks!
fid = fopen([pathname,filename]);
tline = fgetl(fid);
CX = [];
CY = [];
CZ = [];
while ischar(tline)
% skip < and >
tline = substr(tline, 1, length(tline)-2)
% extract numbers
temp = textscan(tline,'%n%n%n', 'delimiter',',');
CX(end+1,:) = [temp(1)];
CY(end+1,:) = [temp(2)];
CZ(end+1,:) = [temp(3)];
tline = fgetl(fid);
end
fclose(fid);
and then plot it using
plot3(CX, CY, CZ)
function call.
Add the check for "Tech4:" at the beginning however...
I think you can also directly use textscan in a one-liner:
fid = fopen('testFile.txt');
data = textscan(fid,'%*s%f,%f,%f');
fclose(fid);
this loads the values from all rows with the specified format into the variable data.
no matlab around to test it out though.
fscanf is an option to, the same kind of parameters as textscan.
EDIT: typo, you want to detect floats (%f) of course, and not integers (%d)
EDIT2: got matlab and tested it out, this works here for your sample input ^^
fid = fopen('testFile.txt');
data = textscan(fid,'%*s%f%f%f','Delimiter',',<>')
fclose(fid);