From 3c874326a6be737aa9ff588184f6aca61e657468 Mon Sep 17 00:00:00 2001
From: Mike Lynch <m.lynch@sydney.edu.au>
Date: Sat, 7 Feb 2026 11:04:42 +1100
Subject: [PATCH] Equator is done!

---
 cellindex.js               | 31 ++++++++++++++++++++++-
 label_inscribed_600cell.js | 51 ++++++++++++++++++++++++++++++++------
 2 files changed, 74 insertions(+), 8 deletions(-)

diff --git a/cellindex.js b/cellindex.js
index 7bd35bc..97f7d57 100644
--- a/cellindex.js
+++ b/cellindex.js
@@ -154,7 +154,36 @@ export const CELL600_METAMAP = {
     543: 75,
     289: 31,
 
-    
+  48: 114,
+  49: 119,
+  61: 84,
+  68: 85,
+  74: 72,
+  87: 65,
+  234: 8,
+  239: 7,
+  241: 6,
+  248: 5,
+  300: 4,
+  301: 3,
+  356: 82,
+  357: 87,
+  369: 120,
+  376: 113,
+  403: 68,
+  406: 69,
+  444: 86,
+  453: 83,
+  460: 118,
+  469: 115,
+  490: 88,
+  503: 81,
+  525: 116,
+  532: 117,
+  572: 70,
+  581: 67,
+  592: 66,
+  593: 71,
 };
 
 export const CELL120_CELL5 = {
diff --git a/label_inscribed_600cell.js b/label_inscribed_600cell.js
index 2304239..ce19883 100644
--- a/label_inscribed_600cell.js
+++ b/label_inscribed_600cell.js
@@ -197,7 +197,7 @@ export const TEMPERATE_PENTAGONS_I = [
     [ 140, 306, 207, 527, 274 ],
     [ 527, 207, 573, 347, 95 ],
     [ 105, 573, 207, 306, 585 ],
-]
+];
 
 export const TEMPERATE_PENTAGONS = TEMPERATE_PENTAGONS_I.map((f) => {
     return f.map((nid) => CELLINDEX.CELL600_METAMAP[nid])
@@ -222,13 +222,50 @@ export function layer_three(shape, pentagons) {
     }
 }
 
+export const TEMPERATE_APICES = [
+    563,
+    513,
+    285,
+    324,
+    231,
+    487,
+    413,
+    425,
+    378,
+    388,
+    543,
+    289,
+];
 
-/*const cell600 = make_one_600cell();
-const layered = insc600_layers(cell600);
+// this one generates the mapping to the base 600 cell as well, unlike
+// previous versions where I did the mapping by hand 
 
-for( const d in layered ) {
-    console.log(`dist = ${d}`);
-    layer_neighbours(cell600, layered[d]);
+export function equator(i600, b600, apices) {
+    const pairs = [];
+    // get all 30 of the edges on the temperate dodeca
+    for( let i = 0; i < 11; i++ ) {
+        for( let j = i + 1; j < 12; j++ ) {
+            const s = shared_neighbours(i600, [ apices[i], apices[j] ]);
+            if( s.length > 0 ) {
+                const e = s.filter((n) => !(n in CELLINDEX.CELL600_METAMAP));
+                pairs.push([apices[i], apices[j], e]);
+            }
+        }
+    }
+    const MAPPED = Object.values(CELLINDEX.CELL600_METAMAP);
+    const eq = {};
+    for( const pair of pairs ) {
+       const b1 = CELLINDEX.CELL600_METAMAP[pair[0]];
+       const b2 = CELLINDEX.CELL600_METAMAP[pair[1]];
+       const s = shared_neighbours(b600, [ b1, b2 ]);
+       const e = s.filter((n) => !MAPPED.includes(n));
+       if( e.length !== 1 ) {
+           console.log(`Bad value at ${pair}`);
+       } else {
+           eq[pair[2]] = e[0];
+       }
+    }
+    return eq;
 }
 
-*/
+