Add getCenter() and getRadius() to Polygon

[Copilot]

Polygons had no way to compute their geographic centroid or bounding radius, making sliding-window workflows (add coords until radius exceeds limit, then trim from the front) impossible without external computation.

Changes

New: PolygonCenterTrait

Shared trait providing coordinateToXYZ() and haversineDistance() helpers, used by both Polygon and MultiPolygon.

PolygonInterface

• getCenter(): ?CoordinateInterface — geographic centroid; null on empty polygon
• getRadius(): float — max haversine distance (metres) from centroid to any vertex

Polygon

• Maintains incremental unit-sphere sums ($sumX/Y/Z) updated in O(1) for add() and remove() — the hot path for sliding-window use
• Bulk mutations (set(), setCoordinates(), offsetSet(), offsetUnset()) recalculate sums from scratch
• Centroid uses 3D unit-sphere averaging (correct near poles and the ±180 meridian; avoids simple lat/lng mean pitfalls)

MultiPolygon

Implements both methods by iterating all coordinates across sub-polygons via the inherited getCoordinates().

Usage

$polygon = new \League\Geotools\Polygon\Polygon([
    [48.9675969, 1.7440796],
    [48.4711003, 2.5268555],
    [48.9279131, 3.1448364],
    [49.3895245, 2.6119995],
]);

$center = $polygon->getCenter(); // CoordinateInterface — geographic centroid
$radius = $polygon->getRadius(); // float — metres from centroid to farthest vertex

// Sliding-window: add to tail, remove from head
$polygon->add($newCoord);
if ($polygon->getRadius() > $limit) {
    $polygon->remove(0);
}

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• https://api.github.com/repos/doctrine/instantiator/zipball/c6222283fa3f4ac679f8b9ced9a4e23f163e80d0
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/geocoder-php/php-common/zipball/a749e00819d2929bd0ec40fb79853956332970ba
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/myclabs/DeepCopy/zipball/07d290f0c47959fd5eed98c95ee5602db07e0b6a
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/nikic/PHP-Parser/zipball/dca41cd15c2ac9d055ad70dbfd011130757d1f82
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/phar-io/manifest/zipball/54750ef60c58e43759730615a392c31c80e23176
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/phar-io/version/zipball/4f7fd7836c6f332bb2933569e566a0d6c4cbed74
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/php-cache/adapter-common/zipball/8788309be72aa7be69b88cdc0687549c74a7d479
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/IFsND5 /usr/bin/composer install (http block)
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/php-cache/array-adapter/zipball/7658acf46b35a23b7be13e50a2792049e1c678c4
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/IFsND5 /usr/bin/composer install (http block)
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/php-cache/hierarchical-cache/zipball/dedffd0a74f72c1db76e57ce29885836944e27f3
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/IFsND5 /usr/bin/composer install (http block)
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/php-cache/tag-interop/zipball/b062b1d735357da50edf8387f7a8696f3027d328
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/IFsND5 /usr/bin/composer install (http block)
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/php-fig/cache/zipball/213f9dbc5b9bfbc4f8db86d2838dc968752ce13b
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/IFsND5 /usr/bin/composer install (http block)
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/php-fig/container/zipball/c71ecc56dfe541dbd90c5360474fbc405f8d5963
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/php-fig/log/zipball/f16e1d5863e37f8d8c2a01719f5b34baa2b714d3
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/IFsND5 /usr/bin/composer install (http block)
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/php-fig/simple-cache/zipball/408d5eafb83c57f6365a3ca330ff23aa4a5fa39b
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/IFsND5 /usr/bin/composer install (http block)
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/php-http/discovery/zipball/82fe4c73ef3363caed49ff8dd1539ba06044910d
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/IFsND5 /usr/bin/composer install (http block)
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/reactphp/event-loop/zipball/ba276bda6083df7e0050fd9b33f66ad7a4ac747a
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/reactphp/promise/zipball/23444f53a813a3296c1368bb104793ce8d88f04a
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/sebastianbergmann/code-unit-reverse-lookup/zipball/ac91f01ccec49fb77bdc6fd1e548bc70f7faa3e5
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/sebastianbergmann/code-unit/zipball/1fc9f64c0927627ef78ba436c9b17d967e68e120
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/sebastianbergmann/comparator/zipball/e4df00b9b3571187db2831ae9aada2c6efbd715d
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/sebastianbergmann/complexity/zipball/25f207c40d62b8b7aa32f5ab026c53561964053a
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/sebastianbergmann/diff/zipball/ba01945089c3a293b01ba9badc29ad55b106b0bc
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/sebastianbergmann/environment/zipball/830c43a844f1f8d5b7a1f6d6076b784454d8b7ed
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/sebastianbergmann/exporter/zipball/14c6ba52f95a36c3d27c835d65efc7123c446e8c
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/sebastianbergmann/global-state/zipball/b6781316bdcd28260904e7cc18ec983d0d2ef4f6
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/sebastianbergmann/lines-of-code/zipball/e1e4a170560925c26d424b6a03aed157e7dcc5c5
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/sebastianbergmann/object-enumerator/zipball/5c9eeac41b290a3712d88851518825ad78f45c71
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/sebastianbergmann/object-reflector/zipball/b4f479ebdbf63ac605d183ece17d8d7fe49c15c7
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/sebastianbergmann/php-code-coverage/zipball/85402a822d1ecf1db1096959413d35e1c37cf1a5
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/sebastianbergmann/php-file-iterator/zipball/cf1c2e7c203ac650e352f4cc675a7021e7d1b3cf
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/sebastianbergmann/phpunit/zipball/b36f02317466907a230d3aa1d34467041271ef4a
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/sebastianbergmann/recursion-context/zipball/539c6691e0623af6dc6f9c20384c120f963465a0
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/sebastianbergmann/resource-operations/zipball/05d5692a7993ecccd56a03e40cd7e5b09b1d404e
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/sebastianbergmann/type/zipball/75e2c2a32f5e0b3aef905b9ed0b179b953b3d7c7
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/sebastianbergmann/version/zipball/c6c1022351a901512170118436c764e473f6de8c
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/symfony/console/zipball/e1e6770440fb9c9b0cf725f81d1361ad1835329d
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/symfony/deprecation-contracts/zipball/63afe740e99a13ba87ec199bb07bbdee937a5b62
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/symfony/polyfill-ctype/zipball/a3cc8b044a6ea513310cbd48ef7333b384945638
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/symfony/polyfill-intl-grapheme/zipball/380872130d3a5dd3ace2f4010d95125fde5d5c70
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/symfony/polyfill-intl-normalizer/zipball/3833d7255cc303546435cb650316bff708a1c75c
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/symfony/polyfill-mbstring/zipball/6d857f4d76bd4b343eac26d6b539585d2bc56493
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/symfony/polyfill-php84/zipball/d8ced4d875142b6a7426000426b8abc631d6b191
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/symfony/property-access/zipball/fa49bf1ca8fce1ba0e2dba4e4658554cfb9364b1
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/symfony/property-info/zipball/02501d75fd834345da3ecdd8e3200ced39e370f8
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/symfony/serializer/zipball/bd395bbc6fabd136a48e1a6f91b09f88b5050b0b
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/symfony/service-contracts/zipball/45112560a3ba2d715666a509a0bc9521d10b6c43
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/symfony/string/zipball/9f209231affa85aa930a5e46e6eb03381424b30b
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/symfony/type-info/zipball/31f1e40cbf7851c7354281c90eb1b352c4cb8269
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)
• https://api.github.com/repos/theseer/tokenizer/zipball/b7489ce515e168639d17feec34b8847c326b0b3c
  • Triggering command: /usr/bin/php8.3 /usr/bin/php8.3 -n -c /tmp/dccXdY /usr/bin/composer install --no-progress (http block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

---

This section details on the original issue you should resolve

<issue_title>calculate center and radius of polygon?</issue_title>
<issue_description>Is it possible / are there plans to keep track of the center and radius of a polygon?

My use case:

1. first: keep adding coordinates to end of polygon until certain radius is exceeded
2. then: keep removing coordinates from start of polygon until radius is within defined limit

For this I need to calculate the weighted center of the current polygon (not: average of the bounding box) and the radius of the coordinates.

Bonus points when average is calculated by keeping track of the sums of x/y/z (and dividing by number of coordinates) instead of calculating/adding all x/y/z's when center is calculated.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes calculate center and radius of polygon? #152

---

📍 Connect Copilot coding agent with Jira, Azure Boards or Linear to delegate work to Copilot in one click without leaving your project management tool.