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Message from discussion Extra relationships in relations list

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More options Aug 24 2012, 8:53 am
From: Jim Eggert <egge...@verizon.net>
Date: Fri, 24 Aug 2012 08:53:38 -0400
Local: Fri, Aug 24 2012 8:53 am
Subject: Re: Extra relationships in relations list
I beg to differ.  Quoted inline below is a simple GEDCOM file that shows the problem I see.  If you ask for the relationship between the father and the son in this file, in one direction you get just the father-son relationship, in the other direction you get that plus a spurious 1st cousin once removed relationship.

The reason is apparently because the pruning algorithm improperly handles inbreeding in the father's ancestry (Grandpa and Grandma were siblings).  If all "relationships" between father and son go only through the father, then the two are just father and son, and not cousins.  The fact that the father has genetic heritage from the same ancestor in different ways doesn't change this.

I think the pruning algorithm needs to be improved.  It should eliminate relationship paths with a common individual in the ascending side and the descending side unless that individual is the common person at the top of that relationship path.

=Jim

0 @I1@ INDI
1 NAME /Son/
1 SEX M
1 FAMC @F1@
0 @I2@ INDI
1 NAME /Father/
1 SEX M
1 FAMS @F1@
1 FAMC @F2@
0 @I3@ INDI
1 NAME /Grandpa/
1 SEX M
1 FAMS @F2@
1 FAMC @F3@
0 @I4@ INDI
1 NAME /Grandma/
1 SEX F
1 FAMS @F2@
1 FAMC @F3@
0 @I5@ INDI
1 NAME /Great-grandpa/
1 SEX M
1 FAMS @F3@
0 @F1@ FAM
1 HUSB @I2@
1 REFN 24 AUG 2012 08:30:35
2 TYPE Creation Date
1 CHIL @I1@
0 @F2@ FAM
1 HUSB @I3@
1 WIFE @I4@
1 CHIL @I2@
0 @F3@ FAM
1 HUSB @I5@
1 CHIL @I3@
1 CHIL @I4@
0 TRLR

On Aug 24, 2012, at 12:46 AM, John Nairn wrote:

> In summary, as far as I know:

> 1. The most direct relationship is always found
> 2. Extra relationships are found; these are always correct and efforts were taken to prune them only to unique or interesting ones
> 3. From your findings, it seems possible that not all extra relationships are found