X-Authentication-Warning: delorie.com: mail set sender to geda-user-bounces using -f
X-Recipient: geda-user AT delorie DOT com
Date: Fri, 14 Dec 2012 17:28:44 +0100 (CET)
X-X-Sender: igor2 AT igor2priv
To: geda-user AT delorie DOT com
X-Debug: to=geda-user AT delorie DOT com from="gedau AT igor2 DOT repo DOT hu"
From: gedau AT igor2 DOT repo DOT hu
Subject: Re: [geda-user] Find rat lines
In-Reply-To: <50CB4CD3.3080707@zepler.net>
Message-ID: <alpine.DEB.2.00.1212141720400.26605@igor2priv>
References: <20121204183305 DOT 6b04c0dc AT jive DOT levalinux DOT org> <20121208112649 DOT 388a9d22 AT jive DOT levalinux DOT org> <1355011808 DOT 19390 DOT 8 DOT camel AT localhost> <alpine DOT DEB DOT 2 DOT 00 DOT 1212090407031 DOT 26605 AT igor2priv> <1355188647 DOT 12937 DOT 14 DOT camel AT localhost> <A7B4EDBD-3704-4837-9350-A16559C60A2A AT noqsi DOT com>
 <1355442697 DOT 2993 DOT 14 DOT camel AT localhost> <008677C3-7BA0-4B7D-B8E7-D0A5B2CCC573 AT noqsi DOT com> <alpine DOT DEB DOT 2 DOT 00 DOT 1212140350530 DOT 26605 AT igor2priv> <898C7D41-7B55-4D61-9CC6-7ABB560C144E AT noqsi DOT com> <alpine DOT DEB DOT 2 DOT 00 DOT 1212140458230 DOT 26605 AT igor2priv> <5189151C-7C93-4AD6-A154-185C8F7AC203 AT noqsi DOT com>
 <alpine DOT DEB DOT 2 DOT 00 DOT 1212140537520 DOT 26605 AT igor2priv> <6E00459F-C749-4DE5-B182-44A8623E70E8 AT noqsi DOT com> <alpine DOT DEB DOT 2 DOT 00 DOT 1212141012260 DOT 26605 AT igor2priv> <C0A29256-3D74-4C3F-B2A0-150F85C85047 AT noqsi DOT com> <alpine DOT DEB DOT 2 DOT 00 DOT 1212141116350 DOT 26605 AT igor2priv>
 <50CB1FFC DOT 1010600 AT zepler DOT net> <alpine DOT DEB DOT 2 DOT 00 DOT 1212141419090 DOT 26605 AT igor2priv> <50CB4CD3 DOT 3080707 AT zepler DOT net>
User-Agent: Alpine 2.00 (DEB 1167 2008-08-23)
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed
Reply-To: geda-user AT delorie DOT com
Errors-To: nobody AT delorie DOT com
X-Mailing-List: geda-user AT delorie DOT com
X-Unsubscribes-To: listserv AT delorie DOT com
Precedence: bulk



On Fri, 14 Dec 2012, Chris Smith wrote:

> On 14/12/2012 13:41, gedau AT igor2 DOT repo DOT hu wrote:
>>
>> In this system your above method is Markus' first touch method and some
>> extra details. With these details it would work better and would not
>> restrict the user to build traces only in one way, but I still have some
>> questions:
>>
>> 1. what happens if I cut an existing, tagged net in a way a segment
>> falls off? Does it become a floating (not associated) net or, does it
>> keep its tag reflecting original user intention?
>
> IMHO, the system should never automatically change an attribute from a
> specific to a more general value -- to do so is effectively throwing
> away information.  The track segment should keep its association; the
> user can manually change it if desired.

Yes, this is one of the approaches. Advantage is simplicity without losing 
info, drawback is more manual tweaking when one doesn't build things 
incrementally but breaks/rewires.

>> 2. What happens if I draw a line accross the board shorting two random
>> nets? I started the line in the middle of nothing, so it would be
>> floating (if starting point matters; causing 2 shorts); or would it be
>> attached to the net of the first line it hits (first touch; only one
>> short, with the second line)?
>>
>> 3. alternative wording of 2.: what happens if I add an object that
>> connects an existing floating net to two existing non-floating nets in
>> the same time?
>
> To be honest I don't think it really matters, as long as it behaves in a
> consistent manner.  I would suggest inheriting the netname of the first
> connected track and marking a short with the second.

Reasonable choice. By the way, a minimal cut solution would highlight 
something very similar in the same situation. The above method would show 
the crossing, a minimal cut would show the extra line causing the short, 
attaching it to whichever net randomly in case 2 or suggesting to cut 
whichever line at the crossing (leaving a rat behind) in case 3.

So beside this method retrains more information about user intention, 
which is good, in many cases it would highlight something very similar to 
a minimal cut.

This argument is relevant only if the final decision needs to consider 
the extra UI/conceptual features put on the user and/or the effort 
required to implement for a developer.


Regards,

Tibor