Re: Problem with printing plots

[Ben Abbott]

On Mar 9, 2012, at 10:07 AM, Ben Abbott wrote:

> On Mar 9, 2012, at 10:02 AM, Michael Goffioul wrote:
> 
>> On Fri, Mar 9, 2012 at 2:54 PM, Ben Abbott <address@hidden> wrote:
>>> 
>>> On Mar 9, 2012, at 9:05 AM, Michael Goffioul wrote:
>>> 
>>>> On Fri, Mar 9, 2012 at 1:48 PM, Ben Abbott <address@hidden> wrote:
>>>>> On Mar 9, 2012, at 1:08 AM, Jordi Gutiérrez Hermoso wrote:
>>>>> 
>>>>>> 2012/3/9 Jordi Gutiérrez Hermoso <address@hidden>:
>>>>>>> Okay, here is a clue. I just ran this in gdb. There is definitely a
>>>>>>> problem with this code. The reason I'm seeing this is that in my debug
>>>>>>> build I compiled with --enable-bounds-checking. On line 600 of
>>>>>>> src/graphics.cc, the p vector only has two coordinates but is being
>>>>>>> indexed one past the end.
>>>>>>> 
>>>>>>> Ben, I think you understand this code best. Why is this indexing past 
>>>>>>> the end?
>>>>>> 
>>>>>> Sorry, the pos vector. This is being called from by
>>>>>> text::get_properties::get_extent on line 6899.
>>>>>> 
>>>>>> - Jordi G. H.
>>>>> 
>>>>> I took a quick look and am off to work in a minute (running late today).
>>>>> 
>>>>> The text position property is a coordinate pair or triplet (2D or 3D). 
>>>>> The position property for axes and figures are vectors of length 4. The 
>>>>> first two are coordinates for the LL corner and the latter pair are the 
>>>>> width and height.
>>>>> 
>>>>> My impression is that convert_text_position(pos, ...) is written to 
>>>>> accept a position vector as a coordinate triplet or [xLL, yLL, width, 
>>>>> height].
>>>>> 
>>>>> As the position property should be saved as a triplet (z coordinate is 
>>>>> zero if not specified), it looks to me like get_position() should return 
>>>>> (x,y,z). This is the way Matlab & Octave work from the command line.
>>>>> 
>>>>> The other option is to modify convert_text_position to treat pos.numel() 
>>>>> == 2 and pos.numel() == 3 differently.
>>>>> 
>>>>> Thoughts ?
>>>> 
>>>> Any idea where the 2D position is coming from? (I mean, where is it set?)
>>>> 
>>>> Michael.
>>> 
>>> I have no idea why a 2D vector is being returned. The text position 
>>> property is defined in graphics.h.in
>>> 
>>> 4241     BEGIN_PROPERTIES (text)
>>> 4242       text_label_property string u , ""
>>> 4243       radio_property units u , 
>>> "{data}|pixels|normalized|inches|centimeters|points"
>>> 4244       array_property position mu , Matrix (1, 3, 0.0)
>>> 4245       double_property rotation mu , 0
>>> 
>>> I'd expect that both pos = get_position ().matrix_value () or pos = 
>>> position.get () would always return a triplet.
>>> 
>>> I noticed the code below in graphics.h.in. I don't understand what its 
>>> supposed to do, but it looks suspicious to me.
>>> 
>>> 4287   protected:
>>> 4288     void init (void)
>>> 4289       {
>>> 4290         position.add_constraint (dim_vector (1, 2));
>>> 4291         position.add_constraint (dim_vector (1, 3));
>>> 4292         cached_units = get_units ();
>>> 4293         update_font ();
>>> 4294       }
>> 
>> This does not change the text position, but simply relax the
>> constraint on the position property by allowing a 2D vector. What I'm
>> trying to figure out is where the 2D vector is assigned. I also see
>> the code in update_xlabel_position (and similar), but the set_position
>> call also uses a triplet. Maybe the 2D vector is coming from the
>> m-code...
>> 
>> Michael.
> 
> The code that produced Jordi's error is from geometry_images.m. Specifically, 
> ...
> 
> rand ("state", 9);
> x = rand (10, 1);
> y = rand (10, 1);
> tri = delaunay (x, y);
> [vx, vy] = voronoi (x, y, tri);
> triplot (tri, x, y, "b");
> hold on;
> plot (vx, vy, "r");
> [r, c] = tri2circ (tri(end,:), x, y);
> pc = [-1:0.01:1];
> xc = r * sin(pi*pc) + c(1);
> yc = r * cos(pi*pc) + c(2);
> plot (xc, yc, "g-", "LineWidth", 3);
> axis([0, 1, 0, 1]);
> legend ("Delaunay Triangulation", "Voronoi Diagram");
> print -dpdfwrite voronoi.pdf
> 
> I've attached an m-file. I suspect the m-file set() command you're looking 
> for is part of legend.m
> 
> Ben

After running that script I attached, text objects 9 and 10 have position 
vectors of length 2. These are part of the legend.

get (findall (gcf, "type", "text"), "position")
ans = 
{
  [1,1] =

     0.50000  -0.05260   0.00000

  [2,1] =

    -0.05069   0.50000   0.00000

  [3,1] =

     0.00000   1.01462   0.50000

  [4,1] =

     0.50000   1.02921   0.50000

  [5,1] =

     0.50000  -0.15625   0.00000

  [6,1] =

    -0.03125   0.50000   0.00000

  [7,1] =

     0.00000   1.15625   0.50000

  [8,1] =

     0.50000   1.31691   0.50000

  [9,1] =

     0.83526   0.75000

  [10,1] =

     0.83526   0.25000

  [11,1] =

     0   0   0

}

I have no idea why the position isn't returned as a triplet.

Ben