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swiss-projection

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Convert from LV03(EPSG:21781) and LV95(EPSG:2056) to WGS84(EPSG:4326)

github.com/idris-maps/swiss-projection

idris-maps/swiss-projection

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# swiss-projection Convert from LV03(EPSG:21781) and LV95(EPSG:2056) to WGS84(EPSG:4326) Uses the algorithm from [Approximate formulas for the transformation between Swiss projection coordinates and WGS84](https://www.swisstopo.admin.ch/content/swisstopo-internet/en/online/calculation-services/_jcr_content/contentPar/tabs/items/documents_publicatio/tabPar/downloadlist/downloadItems/19_1467104393233.download/ch1903wgs84_e.pdf) (PDF). ## Usage ```javascript import { LV03toWGS, LV95toWGS, WGStoLV03, WGStoLV95, } from 'swiss-projection' ``` Takes any GeoJSON `FeatureCollection`, `Feature` or `Geometry` as well as `coordinates` ### Examples * `Feature` ```javascript const bs_lv95 = {"type":"Feature","properties":{"KTNR":12,"KTNAME":"Basel-Stadt"},"geometry":{"type":"Polygon","coordinates":[[[2618243,1270052],[2616262,1267990],[2614711,1267840],[2614602,1267872],[2613766,1265748],[2613671,1265408],[2611744,1263231],[2611346,1263338],[2610925,1264472],[2608775,1265954],[2608770,1268212],[2611314,1271031],[2613986,1269877],[2615583,1271829],[2618243,1270052]]]}} const bs_wgs = LV95toWGS(bs_lv95) // {"type":"Feature","properties":{"KTNR":12,"KTNAME":"Basel-Stadt"},"geometry":{"type":"Polygon","coordinates":[[[7.68112,47.580912],[7.654713,47.562419],[7.6341,47.561106],[7.632653,47.561397],[7.621479,47.542312],[7.620207,47.539256],[7.594557,47.519714],[7.589275,47.520683],[7.583714,47.530889],[7.555192,47.54425],[7.55517,47.564558],[7.589046,47.589872],[7.624531,47.579442],[7.645826,47.596962],[7.68112,47.580912]]]}} ``` * `Geometry` ```javascript const polygon_lv95 = {"type":"Polygon","coordinates":[[[2618243,1270052],[2616262,1267990],[2614711,1267840],[2614602,1267872],[2613766,1265748],[2613671,1265408],[2611744,1263231],[2611346,1263338],[2610925,1264472],[2608775,1265954],[2608770,1268212],[2611314,1271031],[2613986,1269877],[2615583,1271829],[2618243,1270052]]]} const polygon_wgs = LV95toWGS(polygon_lv95) // {"type":"Polygon","coordinates":[[[7.68112,47.580912],[7.654713,47.562419],[7.6341,47.561106],[7.632653,47.561397],[7.621479,47.542312],[7.620207,47.539256],[7.594557,47.519714],[7.589275,47.520683],[7.583714,47.530889],[7.555192,47.54425],[7.55517,47.564558],[7.589046,47.589872],[7.624531,47.579442],[7.645826,47.596962],[7.68112,47.580912]]]} ``` * `coordinates` ```javascript const coordinates_lv95 = [[[2618243,1270052],[2616262,1267990],[2614711,1267840],[2614602,1267872],[2613766,1265748],[2613671,1265408],[2611744,1263231],[2611346,1263338],[2610925,1264472],[2608775,1265954],[2608770,1268212],[2611314,1271031],[2613986,1269877],[2615583,1271829],[2618243,1270052]]] const coordinates_wgs = LV95toWGS(coordinates_lv95) // [[[7.68112,47.580912],[7.654713,47.562419],[7.6341,47.561106],[7.632653,47.561397],[7.621479,47.542312],[7.620207,47.539256],[7.594557,47.519714],[7.589275,47.520683],[7.583714,47.530889],[7.555192,47.54425],[7.55517,47.564558],[7.589046,47.589872],[7.624531,47.579442],[7.645826,47.596962],[7.68112,47.580912]]] ``` ## CLI usage To be used with [`ndjson-cli`](https://github.com/mbostock/ndjson-cli) ``` npm install swiss-projection -g ``` scripts: * `lv03ToWgs` * `lv95ToWgs` * `wgsToLv03` * `wgsToLv95` ## Example ``` curl https://raw.githubusercontent.com/idris-maps/swiss-geodata-2018/master/data/cantons.json \ | ndjson-split 'd.features' \ | lv95ToWgs ```