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    <p>I tried and failed to do something very similar to this a few days ago. The problem lies in the fact that you can't get a sum of a collection, only the sum of an aggregation.</p> <p>See: <a href="https://groups.google.com/d/topic/neo4j/_MqwGp1a1Oo/discussion" rel="noreferrer">https://groups.google.com/d/topic/neo4j/_MqwGp1a1Oo/discussion</a></p> <p>I hope they'll add some functionality for this in Cypher, but I couldn't get it to work, even with the help of the expert--Michael Hunger.</p> <p><strong>UPDATE</strong> I actually poked at the Cypher code today to make an expression that does exactly this. I'm not sure if it will be accepted by 1.9, but maybe some form of it will get into the community edition soon. </p> <p><strong>UPDATE 2</strong> They've merged in my pull request for <code>reduce</code> into 1.9-SNAPSHOT, I'll update the syntax below.</p> <p>It does basically exactly what you're asking for--a slightly stale version of my data is here: <a href="http://console.neo4j.org/r/2rvznu" rel="noreferrer">http://console.neo4j.org/r/2rvznu</a></p> <p>And here's the Cypher (<strong>NOTE, currently requires 1.9-SNAPSHOT</strong>):</p> <pre><code> START n=node(18) MATCH p=n-[r*]-&gt;m WHERE not(m--&gt;()) WITH extract(x in r: x.score) as scores, length(p) as len RETURN scores, reduce(res=0, x in scores: res + x) as totalscore, len ORDER BY totalscore desc; </code></pre> <p>gives:</p> <pre><code>+------------------------------------------+ | scores | totalscore | len | +------------------------------------------+ | [0.9,0.9,3.7] | 5.5 | 3 | | [0.8,0.79] | 1.59 | 2 | | [0.4,0.75] | 1.15 | 2 | | [0.4,0.45] | 0.8500000000000001 | 2 | +------------------------------------------+ </code></pre>
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    1. COi tried to do find the solution myself and came to the same background as this one, based on the EXTRACT function. this is nowdays probably the only way. i imagine a solution similar to the SHORTESTPATHS or ALLSHORTESTPATHS function, except the traversal pattern will calculate with some weights defined in the entry parameter of such a function,i.e. CHEAPESTPATH(rel.param)
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    2. COTwo questions: A.) Does the Dijkstra algorithm exist within Cypher? B.) Is there a way to define a function like sumcollect() so that Cypher can use it without waiting for a new version/rebuilding your forked source?
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    3. COA) not that I know of. B) not that I know of. Considering throwing out `sumcollect` in favor of a more generic `reduce` function. See pull request comments: https://github.com/neo4j/community/pull/878
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