Merge branch 'main' into tied-rankings

README.md

@@ -119,6 +119,11 @@ Ties should have either equivalent rank or score.
 ]
 ```
 
+## Implementations
+
+* Kotlin https://github.com/brezinajn/openskill
+* Elixir https://github.com/philihp/openskill.ex
+
 ## TODO
 
 - Configurable alternate `gamma` to avoid ill-conditioning problems from large numbers of teams, as discussed in the paper.

benchmark/package.json

@@ -5,7 +5,7 @@
     "csv-parser": "3.0.0",
     "microtime": "3.0.0",
     "ndjson": "2.0.0",
-    "openskill": "1.0.1",
+    "openskill": "1.1.1",
     "ramda": "0.27.1",
     "ts-trueskill": "3.2.0"
   }

package.json

@@ -1,6 +1,6 @@
 {
   "name": "openskill",
-  "version": "1.1.0",
+  "version": "1.1.1",
   "description": "Weng-Lin Bayesian approximation method for online skill-ranking.",
   "scripts": {
     "build": "babel src -d dist",
@@ -27,13 +27,13 @@
   },
   "homepage": "https://github.com/philihp/openskill.js#readme",
   "devDependencies": {
-    "@babel/cli": "7.12.10",
-    "@babel/core": "7.12.10",
-    "@babel/preset-env": "7.12.11",
-    "@babel/register": "7.12.10",
+    "@babel/cli": "7.12.13",
+    "@babel/core": "7.12.13",
+    "@babel/preset-env": "7.12.13",
+    "@babel/register": "7.12.13",
     "@philihp/eslint-config": "4.2.0",
-    "husky": "5.0.6",
-    "lint-staged": "10.5.3",
+    "husky": "5.0.8",
+    "lint-staged": "10.5.4",
     "prettier": "2.2.1"
   },
   "lint-staged": {

src/__tests__/rating.test.js

@@ -24,4 +24,16 @@ describe('rating', () => {
     const { sigma } = rating({ sigma: 6.283185 })
     expect(sigma).toBe(6.283185)
   })
+
+  it('can initialize a mu of zero', () => {
+    expect.assertions(1)
+    const { mu } = rating({ mu: 0 })
+    expect(mu).toBe(0)
+  })
+
+  it('can initialize a sigma of zero', () => {
+    expect.assertions(1)
+    const { sigma } = rating({ sigma: 0 })
+    expect(sigma).toBe(0)
+  })
 })

src/rating.js

@@ -2,8 +2,8 @@ const DEFAULT_MU = 25.0
 const DEFAULT_SIGMA = DEFAULT_MU / 3.0
 
 const rating = (initial) => ({
-  mu: initial?.mu || DEFAULT_MU,
-  sigma: initial?.sigma || DEFAULT_SIGMA,
+  mu: initial?.mu ?? DEFAULT_MU,
+  sigma: initial?.sigma ?? DEFAULT_SIGMA,
 })
 
 export default rating