Question about delaunay precision.

[Willie Maddox]

Hello,

Here is a a sample of some saved Delaunay Triangulaiton data using the "write_to_file" function:

4366 8728 2

-932.286 -456.86

-949.082 -399.486

-951.241 -190.631

...

...

-841.686 -490.896

-841.689 -520.968

-841.689 -522.191

793 794 3 

2 804 805 

783 784 20 

...

...

8484 8487 8724 

8727 8682 8519 

8 8686 8726 

...

For a particular application, however, I needed more precision. 

I tried modifying line 181 in SWIG_CGAL/Triangulations_2/Triangulation_2.h from:

else out << get_data();

to,

else out << std::fixed << std::setprecision(15) << get_data();

and the result looks promising:

4366 8728 2

-932.286071777343750 -456.860137939453125

-949.081542968750000 -399.486114501953125

-951.240783691406250 -190.631210327148438

...

...

-841.686491834052504 -490.895905242047320

-841.689236670315040 -520.967833910861259

-841.689348307647606 -522.190912295210637

793 794 3 

2 804 805 

783 784 20 

...

...

8484 8487 8724 

8727 8682 8519 

8 8686 8726 

...

Is there a way to make this a keyword option of "write_to_file" rather than a 'hard coded' mod?

Maybe something with the flavor,

dt.write_to_file(filename, prec=15)

or

dt.write_to_file(filename, prec=1e-15)

or

dt.write_to_file(filename, prec=machine_precision)

Thoughts?

-Will Maddox

[Sebastien Loriot (GeometryFactory)]

Done.

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[Willie Maddox]

Thanks Sebastien,

Would you mind commenting on the usage?

dt.write_to_file(filename, prec=15)

returns,

TypeError: write_to_file() got an unexpected keyword argument 'prec'

and

dt.write_to_file(filename, 15)

returns,

TypeError: Internal_Triangulation_2_Internal_Contrained_triangulation_2_Constrained_Delaunay_triangulation_2_write_to_file() takes exactly 2 arguments (3 given)

NOTE: I am actually using constrained Delaunay. This shouldn't matter right?

Thanks,

-Will

[Sebastien Loriot (GeometryFactory)]

On 09/26/2013 07:05 PM, Willie Maddox wrote:
> Thanks Sebastien,
>
> Would you mind commenting on the usage?
>
> dt.write_to_file(filename, prec=15)

not sure named parmaters are supported.

>
> returns,
>
> TypeError: write_to_file() got an unexpected keyword argument 'prec'
>
> and
>
> dt.write_to_file(filename, 15)

This one should be correct.

>
> returns,
>
> TypeError:
> Internal_Triangulation_2_Internal_Contrained_triangulation_2_Constrained_Delaunay_triangulation_2_write_to_file()
> takes exactly 2 arguments (3 given)
>
> NOTE: I am actually using constrained Delaunay. This shouldn't matter right?

Try to "touch" CGAL_Triangulation_2.i to be sure the interface is
rebuilt by swig (otherwise only the lib is rebuilt).

Sebastien.

>
> Thanks,
>
> -Will

[Willie Maddox]

That's what it was.  Thanks for adding this.