I'm trying to export a matrix f that is double. My data in f are real numbers in three columns. I want a txt file as an output with the columns separated by tabs. However, when I try the dlmwrite function, just the first column appears as output.
for k = 1:10
f = [idx', firsttime', sectime'];
filename = strcat(('/User/Detection_rerun/AF_TIMIT/1_state/mergedlabels_train/'),(files_train{k,1}),'.lab');
dlmwrite(filename,f,'\t') ;
end
When I use dlmwrite(filename,f,'\t','newline','pc') ; I keep getting an error Invalid attribute tag: \t . I even tried 'tab' instead of '\t' but a similar error appears. Please let me know if you have any suggestions. thank you
This is because you are not calling dlmwrite properly. To specify the delimiter, you must use the delimiter flag, followed by the specific delimiter you want. In your case, you use \t. In other words, you need to do this:
for k = 1:10
f = [idx', firsttime', sectime'];
filename = strcat(('/User/Detection_rerun/AF_TIMIT/1_state/mergedlabels_train/'),(files_train{k,1}),'.lab');
dlmwrite(filename,f,'delimiter','\t') ;
end
BTW, you are using the newline flag with pc, meaning that you are specifying carriage returns that are recognized by a PC. I suggest you leave this out and allow MATLAB to automatically infer this. Only force the newline characters if you know what you're doing.
FWIW, the MATLAB documentation is pretty clear about delimiters and other quirks about the function: http://www.mathworks.com/help/matlab/ref/dlmwrite.html
Related
I am currently trying to read in .csv files that can have different delimiters. At the moment I am using readtable but that only handles one type and the use of textscan isn't really viable as the file contains 50+ columns.
The main two types of delimiter are ';' and ','. I am also using uigetfile in order for the user to select the file.
So I am wondering how I would go about handling more than one type of delimiter? The delimiter is consistent throughout each file and they all contain the same number of columns (hence my use of readtable).
Any suggestions would be greatly appreciated.
Thanks in advance.
I'd recommend you to unify delimiters. Eg. replace all semicolons with commas or vice versa, like that
file = 'bad_delimiters.csv';
fd = fopen(file);
text = fscanf(fd,'%c');
semicolons = strfind(text,';');
text(semicolons) = ',';
fd = fopen('good_delimiters.csv', 'w');
fwrite(fd, text);
If you have MATLAB version R2016b or later you can specify multiple delimiters for readtable by defining a set of import options, as illustrated in this example. You will first create a detectImportOptions object, change the 'Delimiter' property to a cell array of characters, then pass these options to readtable:
opts = detectImportOptions('your_file.csv');
opts.Delimiter = {';', ','};
T = readtable('your_file.csv', opts);
I have 1000 text files and want to read a number from each file.
format of text file as:
af;laskjdf;lkasjda123241234123
$sakdfja;lskfj12352135qadsfasfa
falskdfjqwr1351
##alskgja;lksjgklajs23523,
asdfa#####1217653asl123654fjaksj
asdkjf23s#q23asjfklj
asko3
I need to read the number ("1217653") behind "#####" in each txt file.
The number will follow the "#####" closely in all text file.
"#####" and the close following number just appear one time in each file.
clc
clear
MyFolderInfo = dir('yourpath/folder');
fidin = fopen(file_name,'r','n','utf-8');
while ~feof(fidin)
tline=fgetl(fidin);
disp(tline)
end
fclose(fidin);
It is not finish yet. I am stuck with the problem that it can not read after the space line.
This is another approach using the function regex. This will easily provide a more advanced way of reading files and does not require reading the full file in one go. The difference from the already given example is basically that I read the file line-by-line, but since the example use this approach I believe it is worth answering. This will return all occurences of "#####NUMBER"
function test()
h = fopen('myfile.txt');
str = fgetl(h);
k = 1;
while (isempty(str) | str ~= -1 ) % Empty line returns empty string and EOF returns -1
res{k} = regexp(str,'#####\d+','match');
k = k+1;
str = fgetl(h);
end
for k=1:length(res)
disp(res{k});
end
EDIT
Using the expression '#####(\d+)' and the argument 'tokens' instead of 'match' Will actually return the digits after the "#####" as a string. The intent with this post was also, apart from showing another way to read the file, to show how to use regexp with a simple example. Both alternatives can be used with suitable conversion.
Assuming the following:
All files are ASCII files.
The number you are looking to extract is directly following #####.
The number you are looking for is a natural number.
##### followed by a number only occurs once per file.
You can use this code snippet inside a for loop to extract each number:
regx='#####(\d+)';
str=fileread(fileName);
num=str2double(regexp(str,regx,'tokens','once'));
Example of for loop
This code will iterate through ALL files in yourpath/folder and save the numbers into num.
regx='#####(\d+)'; % Create regex
folderDir='yourpath/folder';
files=cellstr(ls(folderDir)); % Find all files in folderDir
files=files(3:end); % remove . and ..
num=zeros(1,length(files)); % Pre allocate
for i=1:length(files) % Iterate through files
str=fileread(fullfile(folderDir,files{i})); % Extract str from file
num(i)=str2double(regexp(str,regx,'tokens','once')); % extract number using regex
end
If you want to extract more ''advanced'' numbers e.g. Integers or Real numbers, or handle several occurrences of #####NUMBER in a file you will need to update your question with a better representation of your text files.
I want to load an ASCII-file using this syntax:
load('10-May-data.dat')
The returned output variable name should be X10_May_data.
Is there a way to get the variable name in Matlab? If I want to use regular expression to do the translation, how can I do it? For example, put an X before any underscores or digits in the filename and replace any other non-alphabetic characters with underscores.
The who function returns the names of variables in matlab. It also has a built-in regexp for selecting certain items:
X10_May_data = [1 2 3];
save X10_May_data.mat X10_May_data
clear
load X10_May_data.mat
w = who('-regexp','X*')
w =
'X10_May_data'
You can then operate on w{1} to do any substitutions you want. For example, use the strrep function for simple modifications of a string:
newvar = strrep(w{1},'May','latest')
newvar =
X10_latest_data
For more complex modifications, use regexp or regexprep. When you have the new name, you can assign it with eval:
eval([newvar '=' w{1}]) % like typing "X10_latest_data = X10_May_data"
X10_latest_data =
1 2 3
[edit] PS I agree with the comments that eval is usually a bad idea; but sometimes you just need to get something done :) For alternative approaches, see the matlab page on the topic.
I have an application that translates the .csv files I currently have into the correct format I need. But, the files I that I do have seem to have '"' double quotes around them, as seen in this image, which will not work with the program. As a result, I'm using this command to remove them:
for m = 1:currentsize(1)
for n = 1:currentsize(2)
replacement{m,n} = strrep(current{m,n}, '"', '');
end
end
I'm not entirely sure that this works though, as it spits this back at me as it runs:
Warning: Inputs must be character arrays or cell arrays of strings.
When I open the file in matlab, it seems to only have the single quotes around it, which is normal for any other file. However, when I open it in notepad++, it seems to have '"' double quotes around everything. Is there a way to remove these double quotes in any other way? My code doesn't seem to do anything as seen here:
After using xlswrite to write the replacement cell-array to a .csv file, one appears corrupted. Any idea why?
So, my questions are:
Is there any way to remove the quotes in a more efficient manner or without rewriting to a csv?
and
What exactly is causing the corruption in the xlswrite function? The variable replacement seems perfectly normal.
Thanks in advance!
Regarding the "corrupted" file. That's not a corrupted file, that's an xls file (not xlsx). You could verify this opening the text file in a hex editor to compare the signature. This happens when you chose no file extension or ask excel to write a file which can't be encoded into csv. I assume it's some character which causes the problems, try to isolate the critical line writing only parts of the cell.
Regarding your warning, not having the actual input I could only guess what's wrong. Again, I can only give some advices to debug the problem yourself. Run this code:
lastwarn('')
for m = 1:currentsize(1)
for n = 1:currentsize(2)
replacement{m,n} = strrep(current{m,n}, '"', '');
if ~isempty(lastwarn)
keyboard
lastwarn('')
end
end
end
This will launch the debugger when a warning is raised, allowing you to check the content of current{m,n}
It is mentionned in the documentation of strrep that :
The strrep function does not find empty strings for replacement. That is, when origStr and oldSubstr both contain the empty string (''), strrep does not replace '' with the contents of newSubstr.
You can use this user function substr like this :
for m = 1:currentsize(1)
for n = 1:currentsize(2)
replacement{m,n} = substr(current{m,n}, 2, -1);
end
end
Please use xlswrite function like this :
[status,message] = xlswrite(___)
and check the status if it is zero, that means the function did not succeed and an error message is generated in message as string.
I'm quite new to Matlab and programming in general and would love to get some help with the following. I've look here on the website, but couldn't find an answer.
I am trying to use a for-loop and fprintf to give me a bunch of separate text files, whose file names contain the index I use for my for-loop. See for example this piece of code to get the idea of what I'd like to do:
for z=1:20
for x=1:z;
b=[x exp(x)];
fid = fopen('table z.txt','a');
fprintf(fid,'%6.2f, %6.2f\n',b);
fclose(fid);
end
end
What I'm looking for, is a script that (in this case) gives me 20 separate .txt files with names 'table i.txt' (i is 1 through 20) where
table 1.txt only contains [1, exp(1)],
table 2.txt contains [1, exp(1)] \newline [2, exp(2)]
and so on.
If I run the script above, I get only one text file (named 'table z.txt' with all the data appended underneath. So the naming of fopen doesn't 'feel' the z values, but interprets z as a letter (which, seeing the quotation marks doesn't really surprise me)
I think there must be an elegant way of doing this, but I haven't been able to find it. I hope someone can help.
Best,
L
use num2str and string concatenation [ ... ].
fid = fopen( ['table ' num2str(z) '.txt'],'a');
Opening your file in the innermost loop is inefficient, you should create a file as soon as you know z (see example below). To format a string the same way that fprintf, you can use sprintf.
for z=1:20
fname = sprintf('table %d.txt',z);
fid = fopen(fname,'w');
for x=1:z
fprintf(fid,'%6.2f, %6.2f\n', x, exp(x));
end
fclose(fid);
end