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Re: Newbie question


From: Joe Koski
Subject: Re: Newbie question
Date: Fri, 05 Aug 2005 13:44:43 -0600
User-agent: Microsoft-Entourage/11.1.0.040913

on 8/5/05 11:47 AM, Henry F. Mollet at address@hidden wrote:

> Thanks, Joe
> [~] -bash-2.05b 501$ locate image.m
> /usr/local/share/octave/2.1.71/m/image/image.m
> 
> /usr/local/share/octave/2.1.71/site/m/octave-forge/MacOSX/image.m
> [~] -bash-2.05b 502$
> 
> Now please tell me why my set up is using your /MacOSX/image.m that uses
> bmpwrite(A, colors, bmp_name);
> ## Author: Tony Richardson <address@hidden>
> ## Created: July 1994
> ## Adapted-By: jwe
> ## Mac OS X adaptation by J. Koski 6/24/04
> 
> Rather than image/image.m which would require ImageMagick
> ## Author: Tony Richardson <address@hidden>
> ## Created: July 1994
> ## Adapted-By: jwe
> with:
>   ## ImageMagick:
>   im_display = sprintf ("display -geometry %f%% \"%s\"", zoom*100,
> ppm_name);
> 
> Also, am I correct that the same applies to X11/xterm with graphing in X
> gnuplot window. I've tried and again the image, e.g. image(ones(100))
> appeared in Preview.
> Henry
>  
Yes, the Mac OSX .bmp version of image.m would apply for both AquaTerm and
X11 graphics because the image color/gray scale issue is between octave and
gnuplot, and not an AquaTerm problem. I haven't tried the ImageMagick
version of image.m. I have ImageMagick on my machine, but haven't used it
much. There is a binary install of ImageMagick for Mac users out there.
Someone, please let me know if it's better. The advantage of the bmpwrite.m
approach is that it uses existing Mac software, and doesn't require
installation of ImageMagick.

The new gnuplot-4.0 feature that would permit its use as a possible
replacement is called palette modulated 3d (pm3d). The advantage would be
that axis labels, etc. could be drawn outside the plot frame, similar to
MATLAB. To adapt its use for image.m would not be a trivial undertaking,
however.  

Joe


> 
> 
> 
> on 8/4/05 4:19 PM, Joe Koski at address@hidden wrote:
> 
>> When a graphical output has a continuous range of color or gray scale, such
>> as a photograph, octave doesn't currently have a way to pass scale
>> information to gnuplot/aquaterm. As a workaround, Paul Kienzle's bmpwrite.m
>> is used for image.m on a Mac. This allows the image to be written into the
>> .bmp format, which is then automatically opened by the OS X in Preview.
>> 
>> The latest gnuplot 4.0/Aquaterm 1.0 combination now has color/gray scale
>> capabilities. It's a matter of developing the necessary routines.
>> 
>> Joe
>> 
>> 
>> on 8/4/05 4:57 PM, Henry F. Mollet at address@hidden wrote:
>> 
>>> I've recently pointed out a similar problem with respect to contourf(z) in
>>> octave-forge. The output is sent to Preview and I don't understand why.
>>> Henry
>>> octave:62> gset term aqua 0
>>> octave:63> [x,y] = meshgrid(linspace(-2,2,200));
>>> octave:64> z = sinc(sqrt(x.^2 + y.^2));
>>> octave:65> contourf(z);
>>> error: expecting integer index, found 7.300000
>>> error: evaluating argument list element number 1
>>> error: called from `contourf' in file
>>> `/usr/local/share/octave/2.1.71/site/m/octave-forge/plot/contourf.m'
>>> 
>>> octave:65> contourf(z); % works when used for the second time and output
>>> appears in Preview rather than Aquaterm.
>>> 
>>> ## contourf(z,n,w)
>>> ## Plots a filled contour plot of n levels using the current
>>> ## colormap.  The width w is the width of the convolution window
>>> ## which smooths the contours.
>>> ##
>>> ## E.g.,
>>> ##     [x,y] = meshgrid(linspace(-2,2,200));
>>> ##     z = sinc(sqrt(x.^2 + y.^2)) + 0.5*randn(size(x));
>>> ##     contourf(z);
>>> ##
>>> ## Note that the algorithm computes incorrect contours near the
>>> ## edges, which you can see using contourf(sinc(sqrt(x.^2+y.^2)))
>>> ## with x,y from above.
>>> 
>>> ## This program is in the public domain
>>> ## Author: Paul Kienzle <address@hidden>
>>> 
>>> function contourf(z,n,w)
>>>   if nargin < 3, w = 16; end
>>>   if nargin < 2, n = 10; end
>>>   if nargin < 1 || nargin > 3
>>>     usage("contourf(z [, n [, w]])");
>>>   endif
>>> 
>>>   ## convolute the original with a gaussian if desired
>>>   if w > 0
>>>     [x,y] = meshgrid(2.5*linspace(-1,1,w));
>>>     B = exp(-.5*(x.^2+y.^2));
>>>     z = filter2(B,z,"same");
>>>   endif
>>> 
>>>   ## find the contours
>>>   C = colormap;
>>>   colormap(repmat(linspace(0.5,1,n+1)',1,3));
>>>   z = filter2(ones(2)/4,imagesc(z));
>>>   z(z!=fix(z)) = 0;
>>> 
>>>   ## plot the image, with the contours drawn in black.
>>>   colormap([0,0,0; C(linspace(1,rows(C),n+1),:)]);
>>>   image(flipud(z)+1);
>>> 
>>>   ## restore the colormap
>>>   colormap(C);
>>> endfunction
>>> 
>>> 
>>> on 8/4/05 2:17 PM, Melvyn Poore at address@hidden wrote:
>>> 
>>>> Hi folks, I¹m new on the block, so forgive me for asking beginner¹s
>>>> questions.  I¹ve installed Octave 2.1.71, Gnuplot, Aqua and X11 on my Mac
>>>> Ti
>>>> Powerbook 550MHz, OSX 10.4.2.  It all appears to function as it should.
>>>> That was already quite an achievement!
>>>> 
>>>> I¹m working on some sound analysis examples and want to put the waveform
>>>> and
>>>> spectrogram plots together in a two-plot diagram.  This doesn¹t seem to
>>>> work
>>>> because plot() sends its results out via Aqua whereas the output of
>>>> imagesc() appears in a Mac Preview window.  Am I missing some terminal
>>>> setting or something?  I¹ve already set the line
>>>> 
>>>> __gnuplot_set__ term aqua
>>>> 
>>>> in startup/octaverc.
>>>> 
>>>> Any help would be appreciated!
>>>> 
>>>> Melvyn
>>> 
>>> 
>>> 
>>> 
>>> 
>>> -------------------------------------------------------------
>>> Octave is freely available under the terms of the GNU GPL.
>>> 
>>> Octave's home on the web:  http://www.octave.org
>>> How to fund new projects:  http://www.octave.org/funding.html
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>>> -------------------------------------------------------------
>>> 
>> 
>> 
>> 
>> 
>> 
>> -------------------------------------------------------------
>> Octave is freely available under the terms of the GNU GPL.
>> 
>> Octave's home on the web:  http://www.octave.org
>> How to fund new projects:  http://www.octave.org/funding.html
>> Subscription information:  http://www.octave.org/archive.html
>> -------------------------------------------------------------
>> 
> 
> 
> 
> 
> 
> -------------------------------------------------------------
> Octave is freely available under the terms of the GNU GPL.
> 
> Octave's home on the web:  http://www.octave.org
> How to fund new projects:  http://www.octave.org/funding.html
> Subscription information:  http://www.octave.org/archive.html
> -------------------------------------------------------------
> 





-------------------------------------------------------------
Octave is freely available under the terms of the GNU GPL.

Octave's home on the web:  http://www.octave.org
How to fund new projects:  http://www.octave.org/funding.html
Subscription information:  http://www.octave.org/archive.html
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