Re: Locale definitions, dots and commas

["Martin (OpenGeoMap)" <martin opengeomap org>]

Dave Howorth escribió:
> Martin (OpenGeoMap) wrote:
>   
> > I am building an intermediate  unit system for engineeres in Gobject and 
> > i hope publish this library soon.
> > With this system you always work in lineal measures in meters (double), 
> > and you can input others (inches, centimeters)
> >
> > input system - intermediate system -out system
> >
> > you can input in a entry for example (22m, 22 m, 220cm,...) and 
> > internally you have a double always in meters.
> >     
>
> How do you deal with precision? 22 m is not the same as 22.000 m
>
>   

Internally you always have doubles, but you show to the people only 3, 2 
or 0 dezimals,...

You have 16 mantise numbers:
1234.567890123456
123456.7890123456
123456789.0123456
12345678901.23456

In DXF files for example you see always 16 numbers .

This is the double precision IEEE standard:

This is explained very well in GSL API:
http://linux.duke.edu/~mstenner/free-docs/gsl-ref-1.1/gsl-ref_38.html

The important here in mantain the double (16 numbers) in an intermediate 
system. It doesn`t matter what you see in a gtk_entry (22.34555, 
22.346,22.35,).



Regards.