From 49da7cfdb06f3185c969f3f4bc22896d11fe48eb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dandelion=20Man=C3=A9?= <decentralion@dandelion.io>
Date: Fri, 27 Jul 2018 17:04:29 -0700
Subject: [PATCH] Display cred explorer scores as -Log(score) (#535)

@wchargin suggested displaying scores this way. This way, lowest scores
are best, and higher scores are worse. This is a little
counterintuitive, but maybe less counterintuitive than the current
approach, which arbitrarily adds 10 to scores to keep them non-negative,
and results in an arbitrary crossing point where scores become negative
without any particular significance.

Test plan: Travis, and manual inspection of the frontend.
---
 src/app/credExplorer/PagerankTable.js      | 3 +--
 src/app/credExplorer/PagerankTable.test.js | 6 ++----
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/src/app/credExplorer/PagerankTable.js b/src/app/credExplorer/PagerankTable.js
index 8a2bb8b..8d936f8 100644
--- a/src/app/credExplorer/PagerankTable.js
+++ b/src/app/credExplorer/PagerankTable.js
@@ -67,8 +67,7 @@ function edgeVerb(
 }
 
 function scoreDisplay(probability: number) {
-  const modifiedLogScore = Math.log(probability) + 10;
-  return modifiedLogScore.toFixed(2);
+  return (-1 * Math.log(probability)).toFixed(2);
 }
 
 type SharedProps = {|
diff --git a/src/app/credExplorer/PagerankTable.test.js b/src/app/credExplorer/PagerankTable.test.js
index 275f065..a936007 100644
--- a/src/app/credExplorer/PagerankTable.test.js
+++ b/src/app/credExplorer/PagerankTable.test.js
@@ -378,7 +378,7 @@ describe("app/credExplorer/PagerankTable", () => {
     it("renders a score column with the node's log-score", async () => {
       const {element, sharedProps, node} = await setup();
       const {score: rawScore} = NullUtil.get(sharedProps.pnd.get(node));
-      const expectedScore = (Math.log(rawScore) + 10).toFixed(2);
+      const expectedScore = (-Math.log(rawScore)).toFixed(2);
       const contributionColumn = COLUMNS().indexOf("Score");
       expect(contributionColumn).not.toEqual(-1);
       expect(
@@ -528,9 +528,7 @@ describe("app/credExplorer/PagerankTable", () => {
     });
     it("renders a score column with the source's log-score", async () => {
       const {element, contribution} = await setup();
-      const expectedScore = (Math.log(contribution.sourceScore) + 10).toFixed(
-        2
-      );
+      const expectedScore = (-Math.log(contribution.sourceScore)).toFixed(2);
       const contributionColumn = COLUMNS().indexOf("Score");
       expect(contributionColumn).not.toEqual(-1);
       expect(