Re: image, imshow and similar display empty axes

[Ben Abbott]

On Nov 8, 2012, at 4:30 AM, Jan-Timm Kuhr wrote:

> 
> On 02.11.2012, at 14:20, Ben Abbott wrote:
> 
>> *** Please "reply-all" and respond at the bottom of the email ***
>> 
>> On Nov 2, 2012, at 5:16 AM, Jan-Timm Kuhr wrote:
>> 
>>> On 31.10.2012, at 22:02, Ben Abbott wrote:
>>> 
>>>> On Oct 31, 2012, at 3:15 PM, Jan-Timm Kuhr wrote:
>>>> 
>>>>> Hello,
>>>>> I'm working on with octave 3.6.3. on a Mac.
>>>>> When I try to plot a 2D image, say by using image(rand(10)), I get an 
>>>>> correct set of axes, but filled with with white space instead.
>>>>> 1d plots seem to work alright.
>>>>> I suspect that it has something to do with working on a Mac.
>>>>> I found this here https://savannah.gnu.org/bugs/?29522
>>>>> but it links to another thread, which is rather cryptic, at least to me.
>>>>> Thanks a lot for any help,
>>>>> jan
>>>> 
>>>> If you try ...
>>>> 
>>>>    h = image (rand (10))
>>>>    set (h, "cdatamapping", "scaled")
>>>> 
>>>> ... do you get what you expect?
>>>> 
>>>> If so, you can try "imagesc()" instead of "image()"
>>>> 
>>>> Ben
>>> 
>>> Thanks Ben but it does not seem to have anything to do with the scaling of 
>>> the color map.
>>> Best,
>>> Jan
>> 
>> 
>> With Octave 3.6.3 from Fink on MacOS 10.6.8 using Gnuplot 4.6 patchlevel 0 
>> and AquaTerm v1.0.1.
>> 
>> The command  image(rand(10)) produces a solid navy blue image. 
>> imagesc(rand(10)) produces random colors.
>> 
>> I'm get the same result using Octave 3.4.0 from MacPorts (on MacOS 10.7.5 
>> with Gnuplot 4.6 patchlevel 1 and AquaTerm v1.1.1).
>> 
>> Where did you get your Octave, Gnuplot and AquaTerm?  And what version of 
>> MacOS are you running?
>> 
>> Ben
>> 
> 
> Hello Ben,
> I got Octave using MacPorts. I'm quite sure I also got AquaTerm and Gnuplot 
> there, also I might have had earlier manual installations from a different 
> source.
> I'm running MacOS 10.7.5, Octave 3.6.3, AquaTerm 1.1.1, Gnuplot 4.6 
> patchlevel 1.
> Neither image nor images produce anything but an AquaTerm window which only 
> contains a set of empty axes.
> Thanks a lot for your help,
> Jan

I"ve filed a bug report for this problem.

        
http://sourceforge.net/tracker/?func=detail&aid=3583459&group_id=2055&atid=102055

Perhaps it is best to avoid using AquaTerm with gnuplot? My gnuplot includes 
the variants below.

        gnuplot @4.6.1_0+aquaterm+luaterm+pangocairo+qt+x11 (active)

If you include the "qt" variant then the following should work ...

        setenv GNUTERM qt
        close all
        img = uint8 (round (255 * rand (5,4,3)));
        imwrite (img, "image.png", "png");
        img = imread ("image.png");
        image (img)

If it does not, verify that an earlier gnuplot isn't being called.  You can do 
that by typing 

        system ("which gnuplot")

at Octave's prompt.

Ben