I am studying Suever's answer where I do not understand its application with fullfile in Code 1.
Code 1
filename=strcat('/Users/masi/Images/', 'p.1');
save(fullfile(filename,'.mat'),'time');
saveas(her, fullfile(filename,'.png'));
Output
Error using save
Cannot create '.mat' because '/Users/masi/Images/p.1' does not
exist.
Code 2
filename=strcat('/Users/masi/Images/', 'p.1');
save(strcat(filename,'.mat'),'time');
saveas(her, strcat(filename,'.png'));
Success!
Change made based on Daniel's answer
filenameMat=fullfile('/Users/masi/Images/', 'p.1', '.mat');
save(filenameMat,'time');
but still getting
Error using save
Cannot create '.mat' because '/Users/masi/Images/p.1.mat' does not
exist.
I do not understand.
Why is code 1 giving the error?
You are using fullfile for a wrong application. The documentation clearly explains the parameters:
Folder and file names, specified as strings and cell arrays of strings.
You input a filename without extension and a file extension, hat is not what fullfile is made for. It will insert a file separator between both:
>> fullfile('foo','.bar')
ans =
foo\.bar
fullfile would be the right function to construct filename.
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 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 have some data in a cell array,
data2={[50,1;49,1;26,1];...
[36,2;12,2;37,2;24,2;47.3,2];}
and names in another cell array,
names2={'xxx/01-ab-07c-0fD3/0';'xxx/01-ab-07s-0fD3/6';}
I want to extract a subset of the data,
data2_subset=data2{1,:}(:,1);
then a temporary file name,
tempname2=char(names2(2));
an save the subset to a text file with
save (tempname2, 'data2_subset', '-ASCII');
But I get this error message: _
Error using save
Cannot create '6' because 'xxx/01-ab-07s-0fD3' does not exist.
To try to understand what is happening, I created a mock dataset with simpler names:
names={'12-05';'14-03'};
data={[50,1;29,1;25,1];[35,2;22,2;16,2;38,2];[40,3;32,3;10,3;44,3;43,3];};
data_subset=data{1,:}(:,1);
tempname=char(names(2));
save (tempname, 'data_subset', '-ASCII');
in which case the save command works properly.
Unfortunately I still do not understand what the problem is in the first case. Any suggestions as to what is happening, and of possible solutions?
MATLAB is interpreting the the forward slashes (/) as directory separators and 6 as the intended file name (your second example doesn't have this slash problem).
Since the relative directory tree xxx/01-ab-07s-0fD3/ doesn't exist, MATLAB can't create the file.
To solve the problem, you can either create the directories beforehand using mkdir():
>> pieces = strsplit(tempname2,'/');
>> mkdir(pieces{1:2});
>> save(tempname2, 'data2_subset', '-ASCII');
or replace the / with some other benign symbol like _:
>> tempname3= strrep(tempname2,'/','_');
>> save (tempname3, 'data2_subset', '-ASCII');
(which works for me).
I want to read some "xlsx" & "txt" files from directory and process on that. Names of the files are the random word.
so I used a function(getAllFiles) to obtain all directions of those files which I founded in this link: How to get all files under a specific directory in MATLAB?.
when I want to use those direction in dlmread or xlsread it give an error as bellow:
??? Error using ==> dlmread at 55
Filename must be a string.
the code is as follow :
fileList = getAllFiles('/home/Network/econimi/SSS')
A=dlmread(fileList(2));
how can I convert fileList to the string format?
The output of getAllFiles is a cell array. As stated in the manual 'Cell array indices in smooth parentheses refer to sets of cells' which means fileList(2) is a cell as well. To access an element of a cell array, use curvy brackets.
Try:
A=dlmread(fileList{2});
I want to write output of code periodically in different files in some specific folder.
Code I am using is as follows:
for i=1:m
% some other things
if (mod(i,1000)==0)
y=[1:dx:n_x;c_initial.'];
fn = ['/home/alekhine' num2str(i) '.dat'];
fid=fopen(fn);
fprintf(fid,'%6.4f %12.8f\n',y);
fclose(fid);
end
end
But I am getting error from Matlab as follows
Error using ==> fprintf
Invalid file identifier. Use fopen to generate a valid file
identifier.
. What is wrong in the code? Any help will be appreciated.
You didn't give the permission argument to the fopen function, so it is opened for reading only.
See the docs (http://www.mathworks.com/help/techdoc/ref/fopen.html) for valid values for permission.
Just FYI, the preferred way of constructing filenames is to use FULLFILE. In this case, you could do
fn = fullfile('/home/alekhine', [num2str(i), '.dat']);
FULLFILE is preferred because it understands the different file separators on different OS types (i.e. \ on Windows and / on UNIX/Mac).
You seem to be missing a path separator in the path generation:
fn = ['/home/alekhine' num2str(i) '.dat'];
Should be:
fn = ['/home/alekhine/' num2str(i) '.dat'];