Re: Problem with printing plots

[Ben Abbott]

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       }

Ben