From 14b7ade4dbeb1c62e43ac80498534c703e0dbf43 Mon Sep 17 00:00:00 2001
From: Peter Wu <peter@lekensteyn.nl>
Date: Tue, 20 May 2014 23:52:45 +0200
Subject: Moves preprocessing to preprocess.js

The only difference in preprocess is the addition of a new options
parameter to avoid using a global var.
---
 preprocess.js | 74 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)
 create mode 100644 preprocess.js

(limited to 'preprocess.js')

diff --git a/preprocess.js b/preprocess.js
new file mode 100644
index 0000000..03af077
--- /dev/null
+++ b/preprocess.js
@@ -0,0 +1,74 @@
+/* "Optimizes" nodes and edges by dropping uninteresting ones. (for example,
+ * nodes with no edges).
+ */
+/* jshint devel:true */
+
+'use strict';
+
+function preprocess(data, options) {
+    // map userID to nodes
+    var users = {};
+    data.nodes.forEach(function (user, i) {
+        users[user.group] = user;
+    });
+    console.log('Initial nodes count:', data.nodes.length);
+    console.log('Initial edges count:', data.edges.length);
+
+    var ratelimit_count = 0, ratelimit_max = 10;
+    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_count > ratelimit_max) {
+        console.log('Supressed', ratelimit_count, 'messages');
+    }
+    console.log('Valid edges count:', data.edges.length);
+
+    // 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) {
+            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) {
+        users[user.group] = user;
+        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];
+    });
+}
-- 
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