From 717b141cb7151d5a004ed286b34ede520aefc528 Mon Sep 17 00:00:00 2001
From: "Namhyeon, Go" <gnh1201@gmail.com>
Date: Mon, 18 Aug 2025 04:16:52 +0900
Subject: [PATCH] Add clusteredCellsDensity function to extramath.js

Introduces clusteredCellsDensity to evaluate density of selected cells within a grid. Updates module version to 1.0.0 and exports the new function for external use.
---
 lib/extramath.js | 29 ++++++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/lib/extramath.js b/lib/extramath.js
index 8076ff7..db416fd 100644
--- a/lib/extramath.js
+++ b/lib/extramath.js
@@ -70,13 +70,40 @@ function cartesianProduct(arr) {
     }, [[]])
 }
 
+function clusteredCellsDensity(numbers, size, minDensity) {
+    if (!numbers || !numbers.length) return false;
+    if (typeof minDensity === 'undefined') minDensity = 0.6;
+    if (typeof size !== 'number' || size <= 0) size = 4; // default grid size = 4
+
+    // 1. Convert cell number → (x,y) coordinates
+    var coords = numbers.map(function (n) {
+        return { x: n % size, y: Math.floor(n / size) };
+    });
+
+    var xs = coords.map(function (c) { return c.x; });
+    var ys = coords.map(function (c) { return c.y; });
+
+    // 2. Compute bounding box of selected cells
+    var minX = Math.min.apply(Math, xs), maxX = Math.max.apply(Math, xs);
+    var minY = Math.min.apply(Math, ys), maxY = Math.max.apply(Math, ys);
+
+    // 3. Compute area and density
+    var w = maxX - minX + 1;
+    var h = maxY - minY + 1;
+    var boxArea = w * h;
+
+    var density = coords.length / boxArea;
+    return density >= minDensity;
+}
+
 exports.DTM = DTM;
 exports.arrayCos = arrayCos;
 exports.measureSimilarity = measureSimilarity;
 exports.export_measureSimilarity = export_measureSimilarity;
 exports.cartesianProduct = cartesianProduct;
+exports.clusteredCellsDensity = clusteredCellsDensity;
 
-exports.VERSIONINFO = "ExtraMath module (extramath.js) version 0.0.5";
+exports.VERSIONINFO = "ExtraMath module (extramath.js) version 1.0.0";
 exports.AUTHOR = "gnh1201@catswords.re.kr";
 exports.global = global;
 exports.require = global.require;