Thread Subject:

Undefined function or variable - for no reason...

Matlab has gone mad! It won't accept any declaration other than predeclared matlab functions (say, fft). Almost any other function call returns 'Undefined function or method bla bla'.

I know you'll think that I don't have the path defined correctly, or that my function is not defined properly, but this is not the case. I am trying to call functions or script located in the directory i am currently browsing.

Tab autocompletes their name when I start typing the first few letters.
But as soon as I press enter, matlab gets confused. I have been using matlab for years, never encountered this problem.

Even weirder, I can copy those files in a different folder, and sometimes, just sometimes, they will work. For a bit. Before becoming un-callable again.

This does not concern all the files I am using, just some. they can be on a different drive, too.

Does anyone have any clue what is going on?

"Theophane " <theo.weber@hotmail.com> wrote in message
news:huspi6$6ko$1@fred.mathworks.com...
> Matlab has gone mad! It won't accept any declaration other than
> predeclared matlab functions (say, fft). Almost any other function call
> returns 'Undefined function or method bla bla'.
>
> I know you'll think that I don't have the path defined correctly, or that
> my function is not defined properly, but this is not the case. I am trying
> to call functions or script located in the directory i am currently
> browsing.
>
> Tab autocompletes their name when I start typing the first few letters.
> But as soon as I press enter, matlab gets confused. I have been using
> matlab for years, never encountered this problem.
>
> Even weirder, I can copy those files in a different folder, and sometimes,
> just sometimes, they will work. For a bit. Before becoming un-callable
> again.
> This does not concern all the files I am using, just some. they can be on
> a different drive, too.
>
> Does anyone have any clue what is going on?

Send a listing of the names of the files in that directory to Technical
Support so they can investigate what's going on.

--
Steve Lord
slord@mathworks.com
comp.soft-sys.matlab (CSSM) FAQ: http://matlabwiki.mathworks.com/MATLAB_FAQ
To contact Technical Support use the Contact Us link on
http://www.mathworks.com

Hi,

I am facing the same problem today.

I try to run the .m file in my current directory and Matlab would give the message - "Undefined function or variable". I add the current path and still it does not recognize any .m file in the current directory.

Moreover, any new .m file is not running at all, while some of the old .m files I executed previously are working fine.

Any help is most appreciated!

Many thanks,
Sundeep

"Steven Lord" <slord@mathworks.com> wrote in message <hute1f$ifa$1@fred.mathworks.com>...
>
> "Theophane " <theo.weber@hotmail.com> wrote in message
> news:huspi6$6ko$1@fred.mathworks.com...
> > Matlab has gone mad! It won't accept any declaration other than
> > predeclared matlab functions (say, fft). Almost any other function call
> > returns 'Undefined function or method bla bla'.
> >
> > I know you'll think that I don't have the path defined correctly, or that
> > my function is not defined properly, but this is not the case. I am trying
> > to call functions or script located in the directory i am currently
> > browsing.
> >
> > Tab autocompletes their name when I start typing the first few letters.
> > But as soon as I press enter, matlab gets confused. I have been using
> > matlab for years, never encountered this problem.
> >
> > Even weirder, I can copy those files in a different folder, and sometimes,
> > just sometimes, they will work. For a bit. Before becoming un-callable
> > again.
> > This does not concern all the files I am using, just some. they can be on
> > a different drive, too.
> >
> > Does anyone have any clue what is going on?
>
> Send a listing of the names of the files in that directory to Technical
> Support so they can investigate what's going on.
>
> --
> Steve Lord
> slord@mathworks.com
> comp.soft-sys.matlab (CSSM) FAQ: http://matlabwiki.mathworks.com/MATLAB_FAQ
> To contact Technical Support use the Contact Us link on
> http://www.mathworks.com
>

Hi,

May I know how you are trying to run the file?
I mean,r u running in the command window or directly from the m-file.
Also,please check your function name's & variables names are not the same.

Shan!


"teki " <radiotek@gmail.com> wrote in message <i3s1tq$l3n$1@fred.mathworks.com>...
> Hi,
>
> I am facing the same problem today.
>
> I try to run the .m file in my current directory and Matlab would give the message - "Undefined function or variable". I add the current path and still it does not recognize any .m file in the current directory.
>
> Moreover, any new .m file is not running at all, while some of the old .m files I executed previously are working fine.
>
> Any help is most appreciated!
>
> Many thanks,
> Sundeep
>
> "Steven Lord" <slord@mathworks.com> wrote in message <hute1f$ifa$1@fred.mathworks.com>...
> >
> > "Theophane " <theo.weber@hotmail.com> wrote in message
> > news:huspi6$6ko$1@fred.mathworks.com...
> > > Matlab has gone mad! It won't accept any declaration other than
> > > predeclared matlab functions (say, fft). Almost any other function call
> > > returns 'Undefined function or method bla bla'.
> > >
> > > I know you'll think that I don't have the path defined correctly, or that
> > > my function is not defined properly, but this is not the case. I am trying
> > > to call functions or script located in the directory i am currently
> > > browsing.
> > >
> > > Tab autocompletes their name when I start typing the first few letters.
> > > But as soon as I press enter, matlab gets confused. I have been using
> > > matlab for years, never encountered this problem.
> > >
> > > Even weirder, I can copy those files in a different folder, and sometimes,
> > > just sometimes, they will work. For a bit. Before becoming un-callable
> > > again.
> > > This does not concern all the files I am using, just some. they can be on
> > > a different drive, too.
> > >
> > > Does anyone have any clue what is going on?
> >
> > Send a listing of the names of the files in that directory to Technical
> > Support so they can investigate what's going on.
> >
> > --
> > Steve Lord
> > slord@mathworks.com
> > comp.soft-sys.matlab (CSSM) FAQ: http://matlabwiki.mathworks.com/MATLAB_FAQ
> > To contact Technical Support use the Contact Us link on
> > http://www.mathworks.com
>

Hi Shan,

I tried running the file from both the command window and directly from the m-file but neither works. The function and variable names are not conflicting.

The same function works fine on my pc (with r2008a), but not on my laptop running matlab r2009a. Even a simple m-file to display a message won't run on my laptop now.

On some other pages, someone suggested it might be a problem with the pathdef.m file, but I am not sure...I even added the path of the current directory before running the m-file, but to no avail!

Sundeep

"Shanmugam Kannappan" <shanmugambe@gmail.com> wrote in message <i3s2ps$i16$1@fred.mathworks.com>...
> Hi,
>
> May I know how you are trying to run the file?
> I mean,r u running in the command window or directly from the m-file.
> Also,please check your function name's & variables names are not the same.
>
> Shan!
>
>
> "teki " <radiotek@gmail.com> wrote in message <i3s1tq$l3n$1@fred.mathworks.com>...
> > Hi,
> >
> > I am facing the same problem today.
> >
> > I try to run the .m file in my current directory and Matlab would give the message - "Undefined function or variable". I add the current path and still it does not recognize any .m file in the current directory.
> >
> > Moreover, any new .m file is not running at all, while some of the old .m files I executed previously are working fine.
> >
> > Any help is most appreciated!
> >
> > Many thanks,
> > Sundeep
> >
> > "Steven Lord" <slord@mathworks.com> wrote in message <hute1f$ifa$1@fred.mathworks.com>...
> > >
> > > "Theophane " <theo.weber@hotmail.com> wrote in message
> > > news:huspi6$6ko$1@fred.mathworks.com...
> > > > Matlab has gone mad! It won't accept any declaration other than
> > > > predeclared matlab functions (say, fft). Almost any other function call
> > > > returns 'Undefined function or method bla bla'.
> > > >
> > > > I know you'll think that I don't have the path defined correctly, or that
> > > > my function is not defined properly, but this is not the case. I am trying
> > > > to call functions or script located in the directory i am currently
> > > > browsing.
> > > >
> > > > Tab autocompletes their name when I start typing the first few letters.
> > > > But as soon as I press enter, matlab gets confused. I have been using
> > > > matlab for years, never encountered this problem.
> > > >
> > > > Even weirder, I can copy those files in a different folder, and sometimes,
> > > > just sometimes, they will work. For a bit. Before becoming un-callable
> > > > again.
> > > > This does not concern all the files I am using, just some. they can be on
> > > > a different drive, too.
> > > >
> > > > Does anyone have any clue what is going on?
> > >
> > > Send a listing of the names of the files in that directory to Technical
> > > Support so they can investigate what's going on.
> > >
> > > --
> > > Steve Lord
> > > slord@mathworks.com
> > > comp.soft-sys.matlab (CSSM) FAQ: http://matlabwiki.mathworks.com/MATLAB_FAQ
> > > To contact Technical Support use the Contact Us link on
> > > http://www.mathworks.com
> >

Dear teki,

it would be helpful, if you give us a complete description of what has happened:
1. Did Matlab work fine before?
2. What has happened in between?
3. Does "path" reply the expected toolbox folders?
4. Do you have read access to these folders?
5. Does WHICH find any of the toolbox functions?
6. Are you sure that there are no naming conflicts? If so, why?
7. Does Matlab provide any error messages, if yes, please post them.
8. Further ideas of what might be helpful to identify the problem?

Kind regards, Jan

Hi Jan,

Thanks for your reply. In response to your questions;

1. Matlab worked fine before
2. I discovered this problem four days ago. I had to go back to my desktop to run this function. Today, it worked once when I copied the file from my pc, and saved the file with a different file name on my laptop. I thought that was it, but on subsequent attempts, the m-file would not run.
3. Yes
4. Yes
5. Yes
6. I am quite positive about that. I don't understand why the same m-file runs without any error on my desktop but fails completely on my laptop.
7. Error reads - "undefined function or variable".
8. I am not sure what else can I say about this.

Many thanks,
Sundeep


"Jan Simon" <matlab.THIS_YEAR@nMINUSsimon.de> wrote in message <i3scmp$t6t$1@fred.mathworks.com>...
> Dear teki,
>
> it would be helpful, if you give us a complete description of what has happened:
> 1. Did Matlab work fine before?
> 2. What has happened in between?
> 3. Does "path" reply the expected toolbox folders?
> 4. Do you have read access to these folders?
> 5. Does WHICH find any of the toolbox functions?
> 6. Are you sure that there are no naming conflicts? If so, why?
> 7. Does Matlab provide any error messages, if yes, please post them.
> 8. Further ideas of what might be helpful to identify the problem?
>
> Kind regards, Jan

"teki " <radiotek@gmail.com> wrote in message <i3s9jc$85u$1@fred.mathworks.com>...
> Hi Shan,
>
> I tried running the file from both the command window and directly from the m-file but neither works. The function and variable names are not conflicting.
>
> The same function works fine on my pc (with r2008a), but not on my laptop running matlab r2009a. Even a simple m-file to display a message won't run on my laptop now.
>
> On some other pages, someone suggested it might be a problem with the pathdef.m file, but I am not sure...I even added the path of the current directory before running the m-file, but to no avail!
>
> Sundeep

it looks like you might have a broken hd...

us

us wrote:
> "teki " <radiotek@gmail.com> wrote in message
> <i3s9jc$85u$1@fred.mathworks.com>...
>> Hi Shan,
>>
>> I tried running the file from both the command window and directly
>> from the m-file but neither works. The function and variable names are
>> not conflicting.
>>
>> The same function works fine on my pc (with r2008a), but not on my
>> laptop running matlab r2009a. Even a simple m-file to display a
>> message won't run on my laptop now.
>>
>> On some other pages, someone suggested it might be a problem with the
>> pathdef.m file, but I am not sure...I even added the path of the
>> current directory before running the m-file, but to no avail!
>>
>> Sundeep
>
> it looks like you might have a broken hd...

Or a corrupted Matlab installation.

I'd probably start by removing the matlab preferences file.

Dear teki,

> 7. Error reads - "undefined function or variable".

Please copy the complete message. Sometimes there is a subtle difference between the exact message and the thing one means to have read (sorry, I have the strong impression, that this is not English anymore - I want to say:
While it is in general a good idea to think before posting, for error messages it is the other way around: post instead of thinking.).

Something strange happens, so a tiny detail may carry the important hint.

Jan

Thanks Us and Walter! My hd is fine but I suspect something's wrong with matlab as Walter suggests..

Jan, the exact error message when I try to run (e.g. 'filename.m') reads as:
??? Undefined function or variable 'filename'.

Thanks,
Sundeep



"Jan Simon" <matlab.THIS_YEAR@nMINUSsimon.de> wrote in message <i3smvd$e62$1@fred.mathworks.com>...
> Dear teki,
>
> > 7. Error reads - "undefined function or variable".
>
> Please copy the complete message. Sometimes there is a subtle difference between the exact message and the thing one means to have read (sorry, I have the strong impression, that this is not English anymore - I want to say:
> While it is in general a good idea to think before posting, for error messages it is the other way around: post instead of thinking.).
>
> Something strange happens, so a tiny detail may carry the important hint.
>
> Jan

Did anyone ever find a solution to this? I am having the exact same problem. Tried reinstalling matlab, but no luck.

When I find a folder that works, every script works in that folder. So everytime I start Matlab I have to find a folder that works (totally random each time) and move all my scripts to that folder.

I use Matlab R2010 and Windows 7. I installed Matlab on my D: drive instead of C:, I don't know if that is making Matlab confused. But I have found folders on both my C and my D drive that works.

I had the same problem. It seems that if there is a function in your folder that has the same name of a matlab function (even if it is a function from a pakcage that you did not install), you can have this problem.

The only solution that I found to avoid this problem is to rename all the functions in the folder by adding my name at the end of the function (for instance "yourfunction.m" is then renamed with "yourfunction_yourname.m").

Please, let me know if this worked!

Thanks.

Jeremy

"Øyvind " <oyvdahl@online.no> wrote in message <i6vb1u$36j$1@fred.mathworks.com>...
> Did anyone ever find a solution to this? I am having the exact same problem. Tried reinstalling matlab, but no luck.
>
> When I find a folder that works, every script works in that folder. So everytime I start Matlab I have to find a folder that works (totally random each time) and move all my scripts to that folder.
>
> I use Matlab R2010 and Windows 7. I installed Matlab on my D: drive instead of C:, I don't know if that is making Matlab confused. But I have found folders on both my C and my D drive that works.

I think I have the same problem. I have some functions with the same name as some functions from the Neural Network Package. No functions in that folder will work.

But if I move the contents of that folder to a different folder after Matlab is started, it works.

Oyvind


"Jeremy Lagorse" <jeremy.lagorse@veolia.com> wrote in message <i7cm8g$mms$1@fred.mathworks.com>...
> I had the same problem. It seems that if there is a function in your folder that has the same name of a matlab function (even if it is a function from a pakcage that you did not install), you can have this problem.
>
> The only solution that I found to avoid this problem is to rename all the functions in the folder by adding my name at the end of the function (for instance "yourfunction.m" is then renamed with "yourfunction_yourname.m").
>
> Please, let me know if this worked!
>
> Thanks.
>
> Jeremy
>

"Øyvind" wrote in message <i7equ0$1g3$1@fred.mathworks.com>...
> I think I have the same problem. I have some functions with the same name as some functions from the Neural Network Package. No functions in that folder will work.
>
> But if I move the contents of that folder to a different folder after Matlab is started, it works.
>
> Oyvind
>
>
> "Jeremy Lagorse" <jeremy.lagorse@veolia.com> wrote in message <i7cm8g$mms$1@fred.mathworks.com>...
> > I had the same problem. It seems that if there is a function in your folder that has the same name of a matlab function (even if it is a function from a pakcage that you did not install), you can have this problem.
> >
> > The only solution that I found to avoid this problem is to rename all the functions in the folder by adding my name at the end of the function (for instance "yourfunction.m" is then renamed with "yourfunction_yourname.m").
> >
> > Please, let me know if this worked!
> >
> > Thanks.
> >
> > Jeremy
> >

Have you tried
>> rehash
or
>> rehash path
??
seems to work for me (but I'm not 100% certain)

"Shai " <shai.bagon@weizmann.ac.il> wrote in message <inkn7p$fbi$1@fred.mathworks.com>...
> "Øyvind" wrote in message <i7equ0$1g3$1@fred.mathworks.com>...
> > I think I have the same problem. I have some functions with the same name as some functions from the Neural Network Package. No functions in that folder will work.
> >
> > But if I move the contents of that folder to a different folder after Matlab is started, it works.
> >
> > Oyvind
> >
> >
> > "Jeremy Lagorse" <jeremy.lagorse@veolia.com> wrote in message <i7cm8g$mms$1@fred.mathworks.com>...
> > > I had the same problem. It seems that if there is a function in your folder that has the same name of a matlab function (even if it is a function from a pakcage that you did not install), you can have this problem.
> > >
> > > The only solution that I found to avoid this problem is to rename all the functions in the folder by adding my name at the end of the function (for instance "yourfunction.m" is then renamed with "yourfunction_yourname.m").
> > >
> > > Please, let me know if this worked!
> > >
> > > Thanks.
> > >
> > > Jeremy
> > >
>
> Have you tried
> >> rehash
> or
> >> rehash path
> ??
> seems to work for me (but I'm not 100% certain)

I have exactly a same problem!!


"Nick" wrote in message <iudt5e$9q5$1@newscl01ah.mathworks.com>...
> "Shai " <shai.bagon@weizmann.ac.il> wrote in message <inkn7p$fbi$1@fred.mathworks.com>...
> > "Øyvind" wrote in message <i7equ0$1g3$1@fred.mathworks.com>...
> > > I think I have the same problem. I have some functions with the same name as some functions from the Neural Network Package. No functions in that folder will work.
> > >
> > > But if I move the contents of that folder to a different folder after Matlab is started, it works.
> > >
> > > Oyvind
> > >
> > >
> > > "Jeremy Lagorse" <jeremy.lagorse@veolia.com> wrote in message <i7cm8g$mms$1@fred.mathworks.com>...
> > > > I had the same problem. It seems that if there is a function in your folder that has the same name of a matlab function (even if it is a function from a pakcage that you did not install), you can have this problem.
> > > >
> > > > The only solution that I found to avoid this problem is to rename all the functions in the folder by adding my name at the end of the function (for instance "yourfunction.m" is then renamed with "yourfunction_yourname.m").
> > > >
> > > > Please, let me know if this worked!
> > > >
> > > > Thanks.
> > > >
> > > > Jeremy
> > > >
> >
> > Have you tried
> > >> rehash
> > or
> > >> rehash path
> > ??
> > seems to work for me (but I'm not 100% certain)

Hi Theopane,
Did you figure this out? I also encountered this bizarre problem this morning, and I have not found a solution. Any help would be greatly appreciated.
Thanks in advance,
Di

"Theophane " <theo.weber@hotmail.com> wrote in message <huspi6$6ko$1@fred.mathworks.com>...
> Matlab has gone mad! It won't accept any declaration other than predeclared matlab functions (say, fft). Almost any other function call returns 'Undefined function or method bla bla'.
>
> I know you'll think that I don't have the path defined correctly, or that my function is not defined properly, but this is not the case. I am trying to call functions or script located in the directory i am currently browsing.
>
> Tab autocompletes their name when I start typing the first few letters.
> But as soon as I press enter, matlab gets confused. I have been using matlab for years, never encountered this problem.
>
> Even weirder, I can copy those files in a different folder, and sometimes, just sometimes, they will work. For a bit. Before becoming un-callable again.
>
> This does not concern all the files I am using, just some. they can be on a different drive, too.
>
> Does anyone have any clue what is going on?

You cannot have the same function name as an already existing matlab function (either built-in or from one of the libraries). It doesn't matter if you don't have the respective library installed.

I had this problem and couldn't figure it out before I contacted Matlab support.

"Øyvind" wrote in message <jq4v8a$21u$1@newscl01ah.mathworks.com>...
> You cannot have the same function name as an already existing matlab function (either built-in or from one of the libraries). It doesn't matter if you don't have the respective library installed.
>
> I had this problem and couldn't figure it out before I contacted Matlab support.

In fact, this is a false statement.

For example, I do NOT have the image processing toolbox
so imshow does not exist.

>> which imshow
'imshow' not found.

I can define a variable with that name.

>> imshow = 7
imshow =
     7

clear imshow

Now, try creating an imshow function.

>> edit imshow
>> type imshow

function imshow
disp('Gosh, it works fine')

Now, test the code out.

>> imshow
Gosh, it works fine

John

John:
You are right, it is possible to have the same name and make it work. BUT it is also a chance that this will produce errors that are hard to figure out.

Here is an explanation: http://www.mathworks.com/support/solutions/en/data/1-3NP7VQ/index.html

Oyvind

"Øyvind" wrote in message <jq57d4$8be$1@newscl01ah.mathworks.com>...
> John:
> You are right, it is possible to have the same name and make it work. BUT it is also a chance that this will produce errors that are hard to figure out.
>
> Here is an explanation: http://www.mathworks.com/support/solutions/en/data/1-3NP7VQ/index.html
>
> Oyvind

Of course. Name conflicts are always a potential problem. But
it is silly to expect me to know every possible toolbox, and
every existing function name in every toolbox I do not own.

MATLAB does NOT have a problem with me naming a function
something even though they have already used that name in
some toolbox I've never seen or intend to use. That would be
insane.

In fact, I can happily name a function with the same name
as an existing function, as long as I am cognizant of what
I've done, and take care that it does not cause a problem.
Yes, this is dangerous, and even often foolish, but still
possible.

John

"Øyvind" wrote in message <jq57d4$8be$1@newscl01ah.mathworks.com>...
> John:
> You are right, it is possible to have the same name and make it work. BUT it is also a chance that this will produce errors that are hard to figure out.
>
> Here is an explanation: http://www.mathworks.com/support/solutions/en/data/1-3NP7VQ/index.html
>
> Oyvind

------------------------------------------------------------------------------------------

I'm not quite sure what the problem here turned out to be or how you or TMW solved it, but many, many versions ago when MATLAB first created the ‘MATLAB’ directory under ‘Documents’ (on Windows systems), I added the following code to the beginning of my ‘startup.m’ (in ‘toolbox\local’) and have never had problems since (unless I created a new subdirectory while I was running MATLAB and forgot to tell MATLAB about it). The code could probably be improved, and updated to take advantage of new features and syntax, but since it only needs to run once when I launch MATLAB, and it still runs correctly, I haven't changed it significantly unless changes in MATLAB versions required them. (I have all my user files and data collected in a single ‘Documents\MATLAB\’ subdirectory ‘My_Files’ and its subdirectories.)

To use it, change the ‘workfiles = 'My_Files';’ line to the subdirectory name you use. MATLAB will find and run new ‘.m’ files and find new data files created while MATLAB is running if they’re somewhere in an existing subdirectory of ‘My_Files’.


% ================== START ‘ADD WORK FILES TO PATH’ ==================

pathmat = path;

findpath = strfind(pathmat,'\MATLAB');

firstpath = [pathmat(1,1:findpath(1)+6) '\'];

firstpathdir = dir(firstpath);

dirnamemat = char(firstpathdir.name);

for k1 = 1:size(dirnamemat,1)
    if isdir(dirnamemat(k1,:)) && isempty(findstr(dirnamemat(k1,:),'.'))
        workpath = [firstpath dirnamemat(k1,:) '\'];
        workdir = deblank(dirnamemat(k1,:));
    end
end

workfiles = 'My_Files'; % Subdirectory and its subdirectories under 'Documents\MATLAB\' where I have my user files

newpath = genpath(workdir);

scanpath = textscan(newpath,'%s','Delimiter',';');

charpath = char(scanpath{:});

for k1 = 1:size(charpath,1)
    filepath(k1,:) = [firstpath '\' charpath(k1,:)];
end

for k1 = 1:size(charpath,1)
% fprintf(1,'\t%3d %s\n',k1,filepath(k1,:))
    addpath(filepath(k1,:),1)
end

fprintf(1,'\n\t\tWORK FILES "%s" ADDED TO “MATLABPATH” ... \n', workfiles);

% ================== END OF ‘ADD WORK FILES TO PATH’ ==================

I experienced this issue in the following scenario.

Initially I named my .m file HW1.m, it worked fine.
I then renamed my .m file to be HW1-NearestNeighboar.m.

I experienced the dreaded Undefined function or variable error.

I then changed the - to _ and everything worked fine.

Apparenly, MatLab doesn't support - characters in the *.m filename.

"Ben Lange" <blange3@gmail.com> wrote in message
news:kf640u$rn0$1@newscl01ah.mathworks.com...
> I experienced this issue in the following scenario.
>
> Initially I named my .m file HW1.m, it worked fine.
> I then renamed my .m file to be HW1-NearestNeighboar.m.
>
> I experienced the dreaded Undefined function or variable error.
>
> I then changed the - to _ and everything worked fine.
>
> Apparenly, MatLab doesn't support - characters in the *.m filename.

That is correct.

http://www.mathworks.com/help/matlab/matlab_prog/create-functions-in-files.html

"Valid function names follow the same rules as variable names. They must
start with a letter, and can contain letters, digits, or underscores."

If function names were allowed to contain a minus sign, this:

HW1-NearestNeighboar(1)

would be ambiguous -- it could be either a call to the function you wrote or
the result of subtracting the first element of the array NearestNeighboar
from the variable HW1.

--
Steve Lord
slord@mathworks.com
To contact Technical Support use the Contact Us link on
http://www.mathworks.com

On Sun, 10 Feb 2013 22:36:33 -0500, Steven_Lord wrote:

> "Ben Lange" <blange3@gmail.com> wrote in message
> news:kf640u$rn0$1@newscl01ah.mathworks.com...
>> I experienced this issue in the following scenario.
>>
>> Initially I named my .m file HW1.m, it worked fine.
>> I then renamed my .m file to be HW1-NearestNeighboar.m.
>>
>> I experienced the dreaded Undefined function or variable error.
>>
>> I then changed the - to _ and everything worked fine.
>>
>> Apparenly, MatLab doesn't support - characters in the *.m filename.
>
> That is correct.
>
> http://www.mathworks.com/help/matlab/matlab_prog/create-functions-in-files.html
>
> "Valid function names follow the same rules as variable names. They must
> start with a letter, and can contain letters, digits, or underscores."
>
> If function names were allowed to contain a minus sign, this:
>
> HW1-NearestNeighboar(1)
>
> would be ambiguous -- it could be either a call to the function you
> wrote or the result of subtracting the first element of the array
> NearestNeighboar from the variable HW1.

so what he -really- needs is software that will do what he means, not what he says.