Trouble reading the file with strread and textscan

So I'm really new to MATLAB and (un)fortunately, I have to troubleshoot a pretty complicated program/code while learning. Obviously I'm encountering a lot of errors and this one I cannot overcome. Following is the part of the code and I hope the contec\xt will be enough.

DataDate=dir('C:**file path in included here**/');
DayCount=0;
NextMMSI='';
AveCount=0;
AveCount10=0;
AveCount3=0;
for viv=1:length(DataDate)-3
    DayCount=DayCount+1;
    length(DataDate)-3-viv
    kkk=DataDate(viv+3).name;
    fileID = fopen(['C:/**file path in included here**/',DataDate(viv+3).name]);
    Year = strread(kkk(1:4));
    MONTH = strread(kkk(5:6));
    DATE1=strsplit(DataDate(viv+3).name,'.');
    DATE2=cell2mat(DATE1(1,1));

Code goes on but the program stops with the error;

Error using dataread
Trouble reading number from file (row 1, field 1) ==> ._.D
Error in strread (line 48)
[varargout{1:nlhs}]=dataread('string',varargin{:}); %#ok

I have tried changing "strread" to "textscan" as the program suggested but there's no luck.

Hope you might have some advice. TIA!

[per isakson]

Use the function fullfile() instead of

['C:/**file path in included here**/',DataDate(viv+3).name]

Do you use Debug a MATLAB Program and Examine Values While Debugging ?

"._.D" does this string appear in the kkk ?

What are the values of kkk(1:4) and kkk(5:6), respectively.

[per isakson]

I doubt that the content of this text file causes the error. Could it be the name of the file? There is nothing in the file that resambles a date.

No, something like

fileID = fopen( fullfile( 'C:', '**file path in included here**', DataDate(viv+3).name ) );

Run

>> dbstop if error

in the command window. And then start your program again. Execution will halt just before the error is thrown. Try to figure out what variable values causes the error. At the K>> prompt you can do "lots of things".

[per isakson]

Doug Hull did a series of videos, some of them on coding and debugging. One of these is: Debugging in MATLAB Posted by Doug Hull, July 3, 2012

[Jake]

As you suggested, there might be an error in the name of the file. It goes like "yyyymmdd". (ex: 20140701)

I'm still getting the same error despite the suggeted changes.

I think I will follow the suggested Debugging tutorials for a while until I get the hang of it.

If you come up with any other possible alterations, please do comment, I will definitely appreciate it!

Thanks a lot for your support.

[per isakson]

DataDate=dir('C:**file path in included here**/');

What is in that folder? Why the name, DataDate? If you know beforehand that you only want to pick up files with specific characteristics, e.g. starts with '20' and has extension '.txt'

DataDate = dir( fullfile( 'C:', '**file path in included here**', '20*.txt' ) );

alternatively

DataDate = dir( fullfile( 'C:', '**file path in included here**' ) );
ism = ismember( {DataDate.name}, {'..','.'} );
DataDate(ism) = [];

to get rid of the .. and . folder. But they are only two not three. Or as Walter suggests

DataDate([DataDate.isdir]) = [];    % remove all directories including . and ..

"I think kkk refers the name of the .txt file." Replace

Year = strread(kkk(1:4));
MONTH = strread(kkk(5:6));

by

Year = str2double(kkk(1:4));
MONTH = str2double(kkk(5:6));
if isnan(YEAR) || isnan(MONTH)
    fprintf( 2, 'The value of kkk is %s\n', kkk )
end

[Jake]

I think the above mentioned suggestion worked. I'm running the code with these (and some other) alterations and everything seems fine so far. I'm getting another error on another part of the programme ("Illegal use of reserved keyword "end". ") but I think that can be fixed later on.

Thanks!

[per isakson]

"Illegal use of reserved keyword "end". "

Which releases of Matlab are you running? On which release was the code developed? Long shot: Not that long time ago the use of "end" was introduced in indicies, e.g.

>> A = 1:123;
>> A(end-12)
ans =
   111

[Jake]

MATLAB R2017a, if that's what you were asking :)

This error is related to another part or the code, I persume. There's another series of if/end commands here. I'll post it here if I don't solve it.

Thanks again for all the support, I really appreciate the quick responses.

[per isakson]

Yes, R2017a is a perfect answer. Thus, the problem isn't related to end as an index.

[Jake]

Oh okay. Which means the problem is from the code itself. Thanks for the clarification. I'll try troubleshooting it.

Answer 1

[Walter Roberson]

DataDate=dir('C:**file path in included here**/');
for viv=1:length(DataDate)-3

That code is incorrect. It is an attempt to skip the . and .. entries, but the . and .. entries are not certain to be the first two entries. Your code is also not skipping directories, which is your most immediate problem: you have a directory that you are attempting to read from as if it is a file, and the directory happens to contain a file or directory named ._.D

DataDate=dir('C:**file path in included here**/');
DataDate([DataDate.isdir]) = [];    %remove all directories including . and ..

and then loop without skipping any entries.

[Jake]

Thank you very much! I will try this one as well!

Thanks again.

Edit: I wasn't very clear about "attempt to skip the . and .. entries, but the . and .. entries are not certain to be the first two entries".

(again, my apologies, I'm very new and trying something quite complex, as far as I understand)

I tried the changes which you've suggested but I'm still getting the same error without any changes :(. I'll keep trying and will post here if I get any updates.

Thank you!

[Walter Roberson]

When you dir() a directory name, at some point in the results, there will be an entry named '.' and another entry named '..' . Much of the time those are the first two entries. It is common for people to skip those two entries by starting using from the third directory entry like your code does. However that is a bug: none of the operating systems and file systems that MATLAB is supported on promise that '.' and '..' will be the first two entries, and several of the combinations MATLAB is supported on promise that those will not be the first two entries under some reasonable circumstances. You are using MS Windows, which makes no promises about the order entries are returned in, but most of the time '.' and '..' might not be the first two entries if there are files or directories named starting with any of the character space or !"#$%&'()*+,-. There is evidence that your directory has entries named starting with '.' and your code does not expect that possibility and is ending up reading a directory as if it were a file.

Answer 2

[per isakson]

"Illegal use of reserved keyword "end". "

Deleting some code may leave a spurious end sometimes far to the right outside the visible pane.

This code snippet throws the error

Error: File: Limitations.m Line: 6 Column: 29
Illegal use of reserved keyword "end". 

The Code Analyzer Report might be helpful

The Code Analyzer Report processes one full folder at a time. The result may look overwhelming, but why not give it a try. The numbers to the left of the messages are hyperlinked to the lines in the m-file.

Afterthought

You wrote: "Which means the problem is from the code itself". Yes, most likely it's a syntax error that the Code Analyzer detects before the code is executed.

The error message always(?) comes together with a line telling which line of code throw the error. e.g.

Error: File: Limitations.m Line: 6 Column: 29
Illegal use of reserved keyword "end". 

First thing is to search that line for a syntax error.

[Jake]

I'm trying out the Code Analyzer Report but apparently there's one too many errors to be fixed. Also, the error message didn't come with a line that tells where the error is, unfortunately.

I have this on the Code Analyzer Report.

"FOR might not be aligned with its matching END"

Does an END has to be aligned with its other command?

[Walter Roberson]

No, end do not have to be aligned, but it is common that when they are not aligned for there to be an overlooked nesting problem. It is usually easiest to select the whole file and use the Smart Indent feature to get automatic alignment.

[Jake]

I just double-checked and the Smart Ident Feature is applied. Still end up getting the aforementioned error.

I'm sorry about the rookie questions, guys. I really appreciate your responses!

[Walter Roberson]

If you attach the .m file someone might have a look.

[per isakson]

I find it hard to believe that Matlab proper would produce the message

"FOR might not be aligned with its matching END"

As Walter says, you don't need to align for,end. This one-liner is legal

>> for jj = 1:6, a = jj; end
>> 

However, I made a report for my folder cssm, which contains a lot of code related to my answering in this forum and the Matlab newsgroup. I search that report for END and got many hits.

I copy&pasted line 290-295 to a new file

Conclusion

Code Analyzer warns for severly non-aligned end because "the most common cause is an extra or a missing end"

The Code Analyzer message isn't neccesarily related to the error message, "Illegal use of reserved keyword "end". "

[per isakson]

"the error message didn't come with a line that tells where the error is"

In my Code Analyzer report of the folder, cssm, every message has a linked line number.

Most Code Analyzer messages are tips and warnings. The report doesn't tell which are errors. That decreases the value of the report. However, error messages seems to contain the word, "error".

[per isakson]

"Illegal use of reserved keyword "end". " and "the error message didn't come with a line that tells where the error is"

Is it this error message that came without a name and line number? That happens for errors in code invoked by timer-objects.

[per isakson]

"I just double-checked and the Smart Ident Feature is applied. Still end up getting the aforementioned error."

I'm lost, I need to look over your shoulder or run your code myself. What happens if you run

1. clearvars
2. dbstop if caught error
3. dbstop if error
4. the code that throws the error, "Illegal use of reserved keyword "end".

???

[Jake]

The error did come with a line number and it is similar to what you have mentioned.

(I know I'm not being very clear by not producing the .m file but truth be told, it is a part of a project :( So I'm reluctant to submit the file or I'll be in trouble. Apologies. But you guys have been a real help so far. I've overcome alot of errors thanks to this thread it self!)

I'll keep working with the suggestions. Big thanks to both of you. Means a lot!