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Re: gEDA-user: transition of pcb internal units to metric (SI, mm)



On 2/8/2011 12:23 PM, Colin D Bennett wrote:
On Tue, 8 Feb 2011 07:27:01 -0800
Edward Hennessy<ehennes@xxxxxxxxxxxxx>  wrote:

On Feb 7, 2011, at 10:41 AM, DJ Delorie wrote:
* nanometer internal units

* 32-bit values on 32-bit machines, 64-bit on 64-bit.

* configure option for 64-bit values regardless of machine in case
you need a board larger than seven feet across.
What about storing both imperial and metric? This way, the
measurements are ket separate until the very last moment when they
need to be converted to one value. A metric element can be
manipulated on screen in an imperial grid and no errors build up.
What problem does this solve?  It certainly makes things much more
complex and will impact performance for no benefit.

Exactly, it solves no problems. Working with 1 nm internal units preserves the exact inch dimensions down to 0.01 mil. Of course, this is convertible back in to inches with no loss of accuracy.

Rick


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