fix up movies index route [wip]

unwind-ui/src/components/MovieList.vue

@@ -29,8 +29,8 @@
           <span class="mediatype">{{ item.media_type }}</span>
         </td>
         <td>
-          <span class="score imdb-score tag is-large" title="IMDb rating (1-10)">{{ imdb_rating(item.imdb_score) }}</span>
-          <span class="score tag is-info is-large" title="User rating (1-10)">{{ imdb_rating(item.user_score) }}</span>
+          <span class="score imdb-score tag is-large" :title="`IMDb rating (1-10) / ${item.imdb_votes} votes`">{{ imdb_rating(item.imdb_score) }}</span>
+          <span class="score tag is-info is-large" :title="`User rating (1-10) / ${item.user_scores.length} votes / σ = ${imdb_stdev(item.user_scores)}`">{{ avg_imdb_rating(item.user_scores) }}</span>
         </td>
         <td>
           <span>{{ duration(item.runtime) }}</span>
@@ -44,6 +44,20 @@
 
 <script lang="ts">
 import { defineComponent } from "vue"
+import { mean, pstdev } from "../utils.ts"
+
+
+function avg_imdb_rating(scores) {
+  return imdb_rating(scores.length === 0 ? null : mean(scores))
+}
+
+function imdb_stdev(scores) {
+  return pstdev(scores.map(imdb_rating_from_score))
+}
+
+function imdb_rating_from_score(score) {
+  return Math.round((score * 9) / 100 + 1)
+}
 
 function imdb_rating(score) {
   if (score == null) {
@@ -85,7 +99,9 @@ export default defineComponent({
     observer.observe(this.$refs.sentinel)
   },
   methods: {
+    avg_imdb_rating,
     imdb_rating,
+    imdb_stdev,
     duration,
   },
 })

unwind-ui/src/utils.ts

@@ -1,3 +1,18 @@
 export function is_object(x) {
   return x !== null && typeof x === "object" && !Array.isArray(x)
 }
+
+export function sum(nums) {
+  return nums.reduce((s, n) => s + n, 0)
+}
+
+export function mean(nums) {
+  return sum(nums) / nums.length
+}
+
+export function pstdev(nums, mu=null) {
+  if (mu === null) {
+    mu = mean(nums)
+  }
+  return Math.sqrt(mean(nums.map((n) => (n - mu) ** 2)))
+}