Re: image, imshow and similar display empty axes

[Jan-Timm Kuhr]

On 08.11.2012, at 14:13, Ben Abbott wrote:

> 
> 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

Thanks for posting the bug report - I'm happy that it's a bug and not the 
user's cluelessness.
While I have not installed qt, x11 works quite nicely.
Thanks a lot,
Jan