Questions regarding Octave

Eric,

   Sending you the working code back again,

%------------------------------ modified code start
% 5/1/96 Eric Jacobsen
%
% Design a butterworth filter and determine the equivalent FIR taps.
%

order=4; % Order of filter.
cutoff=0.25; % Cutoff relative to 1.0 = 1/2 sample rate.

[B,A]=butter(order,cutoff);

%---------------- removed "end;" line (not required) --

Regards
Bharat Pathak

Eric,

   Sending you the working code back again,

%------------------------------ modified code start
% 5/1/96 Eric Jacobsen
%
% Design a butterworth filter and determine the equivalent FIR taps.
%

order=4; % Order of filter.
cutoff=0.25; % Cutoff relative to 1.0 = 1/2 sample rate.

[B,A]=butter(order,cutoff);

%---------------- removed "end;" line (not required) --

Regards
Bharat Pathak

Eric Jacobsen <eric.jacobsen@ieee.org> writes:

> On Sun, 23 Mar 2008 22:29:23 -0400, Randy Yates <yates@ieee.org>
> wrote:
>
>>Hi Eric,
>>
>>There is an octave newsgroup: 
>>
>>  comp.soft-sys.octave
>
> Ah, thanks.   Now the mystery is why the group search in Free Agent
> didn't find that...  
>
>>There is also an IRC channel on freenode.net called #octave. 
>>
>>Regarding your error, would it be possible for you to post the code? I
>>can't help too much just based on what you wrote. 
>
> It seems to be code independent and somehow associated with the file.
> It appears to be complaining about some mysterious whitespace marker
> or something, and since in the one example it's complaining about a
> line well past the end of the file the code probably has nothing to do
> with it.
>
> Nevertheless, try this:
> _________________________________
> %
> % 5/1/96  Eric Jacobsen
> %
> % Design a butterworth filter and determine the equivalent FIR taps.
> %
>
> order=4;	% Order of filter.
> cutoff=0.25;	% Cutoff relative to 1.0 = 1/2 sample rate.
>
> [B,A]=butter(order,cutoff);
>
> end;
>
> ___________________
>
> That's an ancient file that I had laying around that's small and
> exhibits the problem.   For this one it says
>
> error: 'buttgen' undefined near line 60 column 1
>
> Well, the file only has 13 lines.   Grrr.

Yeah, but isn't the function name of the function generating the error
somewhere?

I think I found the error. You need to install octave-forge, which is a
lot of the functionality provided by what we consider mainstream
Matlab. 

I thought they had merged this into the main install for octave 3.0.0,
but apparently not - i didn't have "butter()" defined when I first tried
your snippet. After installing octave-forge, it ran without error (after
removing the extraneous "end" as Bharat noted).
-- 
%  Randy Yates                  % "I met someone who looks alot like you,
%% Fuquay-Varina, NC            %             she does the things you do, 
%%% 919-577-9882                %                     but she is an IBM."
%%%% <yates@ieee.org>           %        'Yours Truly, 2095', *Time*, ELO   
http://www.digitalsignallabs.com

On Sun, 23 Mar 2008 22:53:27 -0500, "bharat pathak"
<bharat@arithos.com> wrote:

>Eric,
>
>   Sending you the working code back again,
>
>%------------------------------ modified code start
>% 5/1/96 Eric Jacobsen
>%
>% Design a butterworth filter and determine the equivalent FIR taps.
>%
>
>order=4; % Order of filter.
>cutoff=0.25; % Cutoff relative to 1.0 = 1/2 sample rate.
>
>[B,A]=butter(order,cutoff);
>
>%---------------- removed "end;" line (not required) --
>
>Regards
>Bharat Pathak

Thanks to everybody for the attention so far.

It's evidently file related, as I copied this back into a new file and
it ran fine.   I took the 'end;' out of the old file (which was legal
matlab syntax back in the day when the file was created), and it still
exhibited the 'undefined' problem.  I copied only the executable lines
out of the old file into a new file and it ran okay, too.

So there's something creeping into the files that causes this
undefined problem, but I'll be damned if I can sort out what it is.
FWIW, I've created a few new files (actually trying to get some work
done), and they have the "undefined" problem as well.

So while I can get a few examples of some very small code snippets
working, I can't get any real work done.   Also, FWIW, I've yet to
find any of my existing library of Matlab files that -don't- exhibit
this "undefined" problem.

To recap what I've tried:

All tested examples of previously existing m files exhibit the
problem.
Most examples of newly written programs exhibit the problem.
A few examples of very small new programs don't exhibit the problem.
Copying three executable lines out of a problematic file into a new
one didn't exhibit the problem.
Other attempts at copying executable lines into new files did exhibit
the problem.


Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.ericjacobsen.org

"Eric Jacobsen" schrieb
> 
> It's evidently file related, as I copied this back into 
> a new file and it ran fine.   I took the 'end;' out of 
> the old file [...]
>

Could there be a CR/LF vs CR problem (linux to Windows 
file transfer)?

If you open the file in Notepad and all lines show as only
one line, then you have a file that follows the Unix file
convention (CR or LF only, I keep forgetting which one it is).
Open it in Wordpad, save it again and from then it should show
up also in Notepad correctly.

This is a long shot, I don't know whether Octave is susceptible
to this type of issue.

YMMV.
Martin

On Mar 23, 11:11 pm, dbd <d...@ieee.org> wrote:
> On Mar 23, 7:49 pm, robert bristow-johnson <r...@audioimagination.com>
> wrote:
>
> > ...
> > yer not the only one, after all it seems intended to be a gnu freeware
> > counterpart to MATLAB.  i contacted Eaton (and got on the Octave
> > developer's list for a little while) to propose they do to Octave what
> > i have, for more than a decade, been trying to get MATLAB to do:
> > generalize handling array indices so that an array can have non-
> > positive integer indices; so that the indices of the upper-left corner
> > need not always be (1,1).
>
> > fell on deaf ears.
>
> > r b-j
>
> So, doesn't that make Octave an accurate counterpart to MATLAB?
>
> But, in the spirit of GNU freeware, what did they say when you offered
> to implement the change for them?

i can't do it all by myself.  i downloaded the whole code base, even
got it to build on my Linux machine, but i could not, for the life of
me, figure out specifically where they were doing their index
calculations.  specifically, for arrays of two dimensions or more, the
*must* be subtracting 1 from the index and multiplying it by the row
length (or, in MATLAB/Octave i think it's the column length) and
adding that to the "less significant" index where either they subtract
one and add it to the array base address, or they don't bother to
subtract 1 and the base address is fudged by 1.  also this should be
intimately related to the index bounds checking that either MATLAB or
Octave do.  i can't find that and no one who was a regular developer
would help me because (like the Math Works) they didn't think that
this modification was a good thing to do which is still just
inexplicable to me.

the Octave source code is spaghetti.  it's shit.  i cannot believe
that people take any pride in code written like that.  (well, i dunno,
i see a lot of shit code where i work.)

r b-j

On Mar 23, 11:11 pm, dbd <d...@ieee.org> wrote:
> On Mar 23, 7:49 pm, robert bristow-johnson <r...@audioimagination.com>
> wrote:
>
> > ...
> > yer not the only one, after all it seems intended to be a gnu freeware
> > counterpart to MATLAB.  i contacted Eaton (and got on the Octave
> > developer's list for a little while) to propose they do to Octave what
> > i have, for more than a decade, been trying to get MATLAB to do:
> > generalize handling array indices so that an array can have non-
> > positive integer indices; so that the indices of the upper-left corner
> > need not always be (1,1).
>
> > fell on deaf ears.
>
> > r b-j
>
> So, doesn't that make Octave an accurate counterpart to MATLAB?
>
> But, in the spirit of GNU freeware, what did they say when you offered
> to implement the change for them?

i can't do it all by myself.  i downloaded the whole code base, even
got it to build on my Linux machine, but i could not, for the life of
me, figure out specifically where they were doing their index
calculations.  specifically, for arrays of two dimensions or more, the
*must* be subtracting 1 from the index and multiplying it by the row
length (or, in MATLAB/Octave i think it's the column length) and
adding that to the "less significant" index where either they subtract
one and add it to the array base address, or they don't bother to
subtract 1 and the base address is fudged by 1.  also this should be
intimately related to the index bounds checking that either MATLAB or
Octave do.  i can't find that and no one who was a regular developer
would help me because (like the Math Works) they didn't think that
this modification was a good thing to do which is still just
inexplicable to me.

the Octave source code is spaghetti.  it's shit.  i cannot believe
that people take any pride in code written like that.  (well, i dunno,
i see a lot of shit code where i work.)

r b-j

On Mar 23, 11:11 pm, dbd <d...@ieee.org> wrote:
> On Mar 23, 7:49 pm, robert bristow-johnson <r...@audioimagination.com>
> wrote:
>
> > ...
> > yer not the only one, after all it seems intended to be a gnu freeware
> > counterpart to MATLAB.  i contacted Eaton (and got on the Octave
> > developer's list for a little while) to propose they do to Octave what
> > i have, for more than a decade, been trying to get MATLAB to do:
> > generalize handling array indices so that an array can have non-
> > positive integer indices; so that the indices of the upper-left corner
> > need not always be (1,1).
>
> > fell on deaf ears.
>
> > r b-j
>
> So, doesn't that make Octave an accurate counterpart to MATLAB?
>
> But, in the spirit of GNU freeware, what did they say when you offered
> to implement the change for them?

i can't do it all by myself.  i downloaded the whole code base, even
got it to build on my Linux machine, but i could not, for the life of
me, figure out specifically where they were doing their index
calculations.  specifically, for arrays of two dimensions or more, the
*must* be subtracting 1 from the index and multiplying it by the row
length (or, in MATLAB/Octave i think it's the column length) and
adding that to the "less significant" index where either they subtract
one and add it to the array base address, or they don't bother to
subtract 1 and the base address is fudged by 1.  also this should be
intimately related to the index bounds checking that either MATLAB or
Octave do.  i can't find that and no one who was a regular developer
would help me because (like the Math Works) they didn't think that
this modification was a good thing to do which is still just
inexplicable to me.

the Octave source code is spaghetti.  it's shit.  i cannot believe
that people take any pride in code written like that.  (well, i dunno,
i see a lot of shit code where i work.)

r b-j

On Mon, 24 Mar 2008 09:56:13 -0700 (PDT), robert bristow-johnson
<rbj@audioimagination.com> wrote:

>the Octave source code is spaghetti.  it's shit.  i cannot believe
>that people take any pride in code written like that.  (well, i dunno,
>i see a lot of shit code where i work.)

I'm sure your 10K+ lines of opensource code looks much better. Where
can we download it to study it?

On Mon, 24 Mar 2008 17:38:57 +0100, "Martin Blume"
<mblume@freesurf.ch> wrote:

>"Eric Jacobsen" schrieb
>> 
>> It's evidently file related, as I copied this back into 
>> a new file and it ran fine.   I took the 'end;' out of 
>> the old file [...]
>>
>
>Could there be a CR/LF vs CR problem (linux to Windows 
>file transfer)?
>
>If you open the file in Notepad and all lines show as only
>one line, then you have a file that follows the Unix file
>convention (CR or LF only, I keep forgetting which one it is).
>Open it in Wordpad, save it again and from then it should show
>up also in Notepad correctly.
>
>This is a long shot, I don't know whether Octave is susceptible
>to this type of issue.
>
>YMMV.
>Martin

Well, I tried that and resaving it with either Wordpad or Word didn't
make any difference.

HOWEVER, somewhere along the way of porting all this crap across
numerous machines (all Windows-based, btw), the filename and extension
became all caps, i.e., BUTTGEN.M.  So I renamed the file to buttgen.m
and PRESTO!  It works.  Jeebuz.

So I changed the name of another, more complex file, from all upper
case to all lower case and that runs and generates a nice plot of a
spectrum (I'm guessing that's what it's supposed to do, it's another
really old file).   In any case, it didn't generate an 'undefined'
error and it did previously when I tried that same file in Octave.

This doesn't explain why some of the new files I created were
problematic, but I'll poke around some more and see what I can sort
out.

Progress in any case, even in the right direction!  ;)

Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.ericjacobsen.org