From 0334aa5e0051b59ce4050fd306b26119466e2991 Mon Sep 17 00:00:00 2001
From: Peter Wu <peter@lekensteyn.nl>
Date: Wed, 21 May 2014 15:13:16 +0200
Subject: Move scripts to subdir

Our scripts end up in js/, third-party libraries end up in lib/.
---
 js/preprocess.js | 98 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 98 insertions(+)
 create mode 100644 js/preprocess.js

(limited to 'js/preprocess.js')

diff --git a/js/preprocess.js b/js/preprocess.js
new file mode 100644
index 0000000..d65c7db
--- /dev/null
+++ b/js/preprocess.js
@@ -0,0 +1,98 @@
+/* "Optimizes" nodes and edges by dropping uninteresting ones. (for example,
+ * nodes with no edges).
+ */
+/* jshint devel:true */
+
+'use strict';
+
+/* find user nodes and remove invalid edges */
+function filterEdges(data, ratelimit_max) {
+    // map userID to nodes
+    var users = {};
+    //data.nodes.length = 10000;
+    data.nodes.forEach(function (user, i) {
+        users[user.group] = user;
+    });
+
+    var ratelimit_count = 0;
+    function ratelimit() {
+        return ++ratelimit_count <= ratelimit_max;
+    }
+    // filter away invalid edges
+    data.edges = data.edges.filter(function (link, i) {
+        var invalid = false;
+        if (!(link.source in users)) {
+            if (ratelimit()) console.warn('Dropping invalid source user',
+                link.source, 'at line', (i + 1), link);
+            invalid = true;
+        }
+        if (!(link.target in users)) {
+            if (ratelimit()) console.warn('Dropping invalid target user',
+                link.target, 'at line', (i + 1), link);
+            invalid = true;
+        }
+        if (link.source === link.target) {
+            if (ratelimit()) console.warn('Dropping self-referencing user',
+                link.target, 'at line', (i + 1), link);
+            invalid = true;
+        }
+        return !invalid;
+    });
+    if (ratelimit_max > 0 && ratelimit_count > ratelimit_max) {
+        console.log('Supressed', ratelimit_count, 'messages');
+    }
+}
+
+function preprocess(data, options) {
+    console.log('Initial nodes count:', data.nodes.length);
+    console.log('Initial edges count:', data.edges.length);
+    filterEdges(data, 10);
+    console.log('Valid edges count:', data.edges.length);
+
+    if (options.minTweetCount > 0) {
+        /* filter away users with almost no tweets */
+        data.nodes = data.nodes.filter(function (node) {
+            return node.tweetCount >= options.minTweetCount;
+        });
+        console.log('Nodes count (ignoring users with fewer than',
+            options.minTweetCount, 'tweets):', data.nodes.length);
+        filterEdges(data, 0);
+    }
+
+    // find all related users by userID
+    var hasRelations = {};
+    data.edges.forEach(function (link) {
+        hasRelations[link.target] = 1;
+        hasRelations[link.source] = 1;
+    });
+
+    if (options.kill_loners) {
+        var hasRelated = {};
+        data.nodes = data.nodes.filter(function (d) {
+            /* Uncomment if it seems to be useful.
+            if (!(d.group in hasRelations) && d.tweetCount >= 100) {
+                console.log('Keeping lonely user with', d.tweetCount, 'tweets');
+                return true;
+            }
+            */
+            return d.group in hasRelations;
+        });
+        console.log('Nodes count (after dropping loners):', data.nodes.length);
+    }
+
+    // prepare data for force layout: map user IDs to indices
+    var userIds_indices = {};
+    data.nodes.forEach(function (user, i) {
+        userIds_indices[user.group] = i;
+    });
+    console.log('UserID to index map:', userIds_indices);
+
+    // change userID of relation edges to indices
+    data.edges.map(function (link) {
+        link.source = userIds_indices[link.source];
+        link.target = userIds_indices[link.target];
+        // for faster lookup, store neighboring nodes per node
+        data.nodes[link.source].relatedTo.push(link.target);
+        data.nodes[link.target].relatedFrom.push(link.source);
+    });
+}
-- 
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