I have a text file with numbers that looks like this:
a.txt
0.001240242769
-0.000829468827
-0.0001689229831
0.0008228798977
-3.86881172e-05
in a MATLAB I used to be able to use
x_in = importdata('a.txt');
and x_in was in fact a vector of 5 double numbers.
I don't know what I changed yesterday but all of a sudden when I use the same function it downloads as char
x_in='0.001240242769
-0.000829468827
-0.0001689229831
0.0008228798977
-3.86881172e-05'
What did I change and how can I fix it back?
The likely cause is that the text file has something that is not recognized as number or delimiter. I would suggest to use load as following:
x_in = load('a.txt', '-ascii');
Related
Basically, I build a list of files using ls, then want to loop through that list, read in a file, and do some stuff. But when I try to read the file in it fails.
Here is an example
r=ls(['Event_2006_334_21_20_11' '/*.r'])
Event_2006_334_21_20_11/IU.OTAV_1.0.i.r
which is a 1x80 char
fopen(r(1,:))
-1
but
fopen('Event_2006_334_21_20_11/IU.OTAV_1.0.i.r')
12 (or whatever its on)
works. I've tried string(r) and char(r) and sprintf('%s',r). If I just build the string like r = ['Event_2006_334_21_20_11' '/IU.OTAV_1.0.i.r'] it works. So it seems something about combining the different variable types that messes it up but I can't seem to find a workaround. Probably something obvious I'm missing.
Any suggestions?
ls returns a matrix of characters, which means each row contains the same number of characters. To indicate the problem, try:
['-' r(1,:) '-']
You will probably notice some whitespaces in front of the -. Unless you want to print the output to the command line, ls is not really useful. As mentioned by Alex, use dir instead.
A further tip regarding your last comment, concatenate file path using fullfile. It makes sure you get one file separator whenever concatenating:
>> fullfile('myfolder','mysubfolder','myfile.m')
ans = myfolder/mysubfolder/myfile.m
>> fullfile('myfolder/','mysubfolder','myfile.m')
ans = myfolder/mysubfolder/myfile.m
>> fullfile('myfolder/','/mysubfolder','myfile.m')
ans = myfolder/mysubfolder/myfile.m
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 have the following simple code, and I tried to use one of the indices from the .txt file. The index that I want is at (4,1) while the size of my matrix in the .txt file is (8,4). When I run the code, MATLAB give me the following error;
Attempted to access q(4,1); index out of
bounds because size(q)=[1,601]
Can someone help me understand why I receive the error and how to fix it?
Here is the code:
q = fileread('sv11edit.txt');
toe = q(4,1)
The answer will depend on the format of the file sv11edit.txt. However, fileread returns a string of characters. In this case, it gives you a string that is 601 characters long. You receive an error because you assume that q is 8 by 4, but this is not the case.
Check what is being stored in q before you try anything like the second line of your code. The function load may be a better alternative to fileread.
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
I am trying to export a double array from MATLAB into a txt file. I can do this easily but the data is not structured how i need it. I need the data to be structured in the following way in the txt file;
-0.0195
-0.0217
-0.0260
-0.0274
-0.0258
-0.0246
-0.0244
-0.0233
-0.0209
-0.0221
Does anyone know how this would be done using dlmwrite?
Maybe something like this?
A=[-0.0195; -0.0217; -0.0260; -0.0274; -0.0258; -0.0246; -0.0244; -0.0233; -0.020;-0.0221];
dlmwrite('example.txt', A, 'newline', 'pc')
The last two argument determines the new line character used (CR or CR+LF), depending on the platform. Use 'pc' for the Windows version, and 'unix' for all others.
For full cross-platformness, you can use the isunix function, and have something like the following preceding your code:
if isunix==true
platform='unix'
else
platform='pc'
end
and then use the platform variable as the last argument in dlmwrite.
If your data is in a row-vector called A this will write it into a column in afile.txt:
dlmwrite('afile.txt',A,'\n')