Re: more graphics changes.

[Daniel J Sebald]

Søren Hauberg wrote:
> John W. Eaton skrev:
>
> > It would be helpful to me if people who have been using the new
> > graphics features could check that I haven't broken too many things.
> > Please report any problems that you find to this list.
>
> I've actually used octave today for some real work so I hit a few bugs:
>
> *) The axis when showing images isn't correct. This was fixed in 
> previous version after some discussions on the behaviour. I think you 
> just have to flip the y-axis. The problem can be illustrated by the 
> following code:
>
>   im = zeros(50, 50);
>   im(30,  5:15) = 1;
>   im(25:35, 10) = 1;
>   imshow(im)
>   hold on; plot(10, 30, 'r*'); hold off
>
> This should show a black image with a white cross. In the center of the 
> white cross a red * should appear.

Well, there may be an error there.  I see some inconsistency using the 
image(x,y,im) form.  Not sure what the convention is.  Note however that the 
baby example of image comes out correct.  Also, location (x,y) in the matrix 
representation of the image doesn't necessarily have to mean (x,y) in the 
plotting space.  Many conventions have the image with reference point at the top 
left (and some have bottom left, unfortunately).  If you can't supply a patch, 
let me know what the convention should be.

Dan