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<div class="moz-cite-prefix">Le 7/05/2014 16:32, Peter K a écrit :<br>
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<blockquote cite="mid:536A4412.6030401@yahoo.de" type="cite">
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</pre>
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When the lazy updates are activated,
* do we still need to update the neighbour points of a node we just
contracted?
</pre>
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Lazy update is exactly for that purpose: updating the priorities of the
neighbour nodes of a contracted node</pre>
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as far as I understand it, lazy update is about checking that the
node we are going to contract has a proper priority by recomputing
its priority, and postponing its contraction if necessary. It does
not seem to be about updating the neighbours of a node that has just
been updated. <br>
<blockquote cite="mid:536A4412.6030401@yahoo.de" type="cite">
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<pre wrap="">* is it still needed to perform periodic updates of all the priorities?
</pre>
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we only do periodic updates for not yet contracted nodes</pre>
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yes, but I feel that the lazy updates actually performs a redundant
function with the periodic updates. <br>
<br>
<blockquote cite="mid:536A4412.6030401@yahoo.de" type="cite">
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Keep in mind: all the ordering and preparation procedure is entirely
heuristic nature. But still it leads to an algorithm with correct
behaviour, no heuristics. The only difference e.g. if we don't do lazy
or periodic updates etc is the quality of how fast is the query, how
fast is the preparation itself and how many shortcuts were produced.</pre>
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Yes, I understand, I just want to make contraction faster without
losing on quality, <br>
hence my remarks<br>
<br>
<blockquote cite="mid:536A4412.6030401@yahoo.de" type="cite">
<pre wrap="">
Peter.
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