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Re: colorbar for decimal images
From: |
Lorenzo Trojan |
Subject: |
Re: colorbar for decimal images |
Date: |
Fri, 30 Oct 2009 18:01:57 +0000 (GMT) |
On Oct 30, 2009, at 7:54 AM, Lorenzo Trojan <address@hidden>
wrote:
> > Hi all,
> >
> > sorry for asking this question, I've been looking around but I
> > couldn't find a solution to this.
> >
> > I have a matrix of intensities. The intensity of each pixel is a
> > double number ranging from e-4 to e-3 and I'd like to produce an
> > image using image() or imshow() and add a colorbar showing the
> > correct range of values. I could do something like:
> >
> > > minmat = min (min (matrix)) ;
> > > maxmat = max (max (matrix)) ;
> > > delmat = maxmat - minmat ;
> > > imgmat = (matrix + minmat) * 64 / delmat ;
> > > image (imgmat);
> > > colormat (hot (64)) ;
> > > colorbar ();
> >
> > but then the colorbar would show the range from 1 to 64.
> >
> > is there a way to change the labels to the colorbar so that it
> > display the range of the original image limits? I tried to look for
> > the axis object associated with the colorbar, but I could't find
> > them...
>
> You can obtain the handle to the colorbar by
>
> hc = findall (gcf, "tag", "colorbar", "type", "axes");
>
> Or when you create the colorbar ...
>
> hc = colorbar ();
>
> Ben
Hi
Thanks for the reply. I downloaded findall which didn't seem to be installed on
my system, from:
http://velveeta.che.wisc.edu/cgi-bin/hgwebdir.cgi/octave/file/tip//scripts/plot/findall.m?rev=HEAD&content-type=text/plain
but is didn't work. When i use it says:
> warning: get: invalid property `showhiddenhandles'
and a bunch of other errors. the second solution also didn't work. Octave
returns:
> error: value on right hand side of assignment is undefined
I've installed octave from the main Ubuntu rep:
> octave:1405> version
> ans = 3.0.1
is this octave version too old?
thanks
Lorenzo