Reweighted range voting: Difference between revisions
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(Added python for RRV. Same code as SPAV roughly.) |
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[[File:RRV Procedure.svg|thumb|RRV Procedure]]
"'''Reweighted range voting'''" (also possibly referred to as '''reweighted score voting''') is one of many [[cardinal proportional representation]] voting systems. It is a [[multi-member system]] (and a variant on [[score voting]]) designed as a natural extension of the [[Webster]] or [[Jefferson Method]] to a [[multi-member system]]. If two-level score (i.e. "[[approval voting]]") ballots are used then it reduces to [[sequential proportional approval voting|sequential proportional approval voting ("SPAV")]]. It is therefore one of the three extensions of [[sequential proportional approval voting]] to score ballots along with [[sequential proportional score voting]] and [[single distributed vote]].
==Procedure==
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# For the final seat available, the two highest-scoring candidates remaining runoff, with the candidate preferred (scored higher) by more reweighted ballots winning the final seat.
==Example
Below is some example code, written in [[Python]] and posted by [[User:Fsargent]]:
<syntaxhighlight lang="python" line>▼
▲<syntaxhighlight lang="python" line="">
import pandas
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print(seated)
</syntaxhighlight>
<syntaxhighlight lang="" line>▼
Here is the output of the script when executed:
▲<syntaxhighlight lang="python" line="">
Red 18.0
Green 10.0
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dtype: float64
['Red', 'Yellow', 'Blue', 'Green']
</syntaxhighlight>The example illustrates the order in which the four candidates are seated (<code>'Red'</code>, then <code>'Yellow'</code>, then <code>'Blue'</code>, then <code>'Green'</code>). After reordering to cluster similar voters, the ballots may be expressed as [[ABIF]] as follows:
<syntaxhighlight lang="text">
1: [Red]/5 = [Blue]/5 > [Yellow]/3 > [Green]/0
2: [Red]/5 = [Blue]/4 > [Yellow]/0 = [Green]/0
1: [Yellow]/5 > [Green]/0 = [Blue]/0 = [Red]/0
1: [Yellow]/4 > [Blue]/3 > [Green]/2 > [Red]/1
1: [Yellow]/2 > [Red]/1 > [Green]/0 = [Blue]/0
1: [Green]/5 > [Blue]/1 > [Red]/0 = [Yellow]/0
1: [Green]/3 > [Red]/1 = [Blue]/1 > [Yellow]/0
</syntaxhighlight>
<code>'Red'</code> and <code>'Blue'</code>are tied in the first round, with scores of "<code>18.0</code>". Because of the tie, the software arbitrarily chooses <code>'Red'</code>(though <code>'Blue'</code> may be arbitrarily chosen with the method in a different software implementation). After that, [[User:RobLa]] gets lost (as of April 2022), so someone else is going to have to explain how <code>'Blue'</code> falls behind <code>'Yellow'</code> in reweighted ballots of the second round.
==Related Systems==▼
If [[Ballot#Approval ballot|approval ballots]] are used,
[[Category:Cardinal voting methods]]
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