[Ipe-discuss] Millimeters grid units

[Otfried Cheong]

On 05/24/2013 06:38 PM, André Lebacq wrote:
> I would like to have a grid with millimeters units (0.5, 1, 2, 4mm).
> I try to set a line like <gridsize name="1 mm" value="2.835"/>
> (72/25.4 = 2.835 pt = 1mm) in a new style sheet, but it seems IPE
> round this value down to 2pt. Is there any way to specify a
> fractional grid size in the style sheet ?

The grid size has to be an integer.  In a previous Ipe version it was 
possible to use fractional grid sizes, but that lead to rounding errors 
that were hard to control, and grid points not really being on the grid.

I intend to make this possible at some point by making the Ipe 
coordinate system flexible (that is, the document can specify that a 
unit of 1 will be, say, 1/10 mm), but this needs to be thought through 
properly (e.g. a linewidth of 1 will also have a different meaning then).

Right now, the only thing you can do is set the grid to, say 3 pts, and 
scale the figure by 2.834646/3.0 when you print it.  Since Ipe was 
designed to make figures for Latex documents, scaling is easy when you 
include the figure.

Cheers,
  Otfried