ptolemy-reproject

Reproject between coordinates systems. Supports EPSG codes.

This project is based on proj4js and PostGIS Spatial Reference table.

It can be used for who needs to deal with more projections than the common web projections (EPSG:4326, EPSG:3857).

Setup

npm install ptolemy-reproject

Coordinate Reference System Options

You can use the EPSG code number, WKT or proj4 string to convert the projections.

Functions

• point
• multipoint
• linestring
• multilinestring
• polygon
• multipolygon

point

const ptolemyReproject = require('ptolemy-reproject');
 
//ptolemyReproject.point(sourceCRS, toCRS, pointCoordinate);
const result = ptolemyReproject.point(4326, 32723, [-46.64, -23.5703]);
console.log(result);
// [ 332629.00686995825, 7392387.8835482355 ]

multipoint

const ptolemyReproject = require('ptolemy-reproject');
 
//ptolemyReproject.multipoint(sourceCRS, toCRS, multipointCoordinate);
const result = ptolemyReproject.multipoint(4326, 32723, [[-46.64, -23.5703], [-47.64, -21.2703]]);
console.log(result);
// [ [ 332629.00686995825, 7392387.8835482355 ],   [ 226053.02820297563, 7645646.386169953 ] ]

linestring

const ptolemyReproject = require('ptolemy-reproject');
 
//ptolemyReproject.linestring(sourceCRS, toCRS, linestringCoordinate);
const result = ptolemyReproject.linestring(4326, 32723, [
  [-46.64624065160751, -23.569855558195446],
  [-46.645567417144775, -23.570371829788982],
  [-46.645462810993195, -23.570465250146203],
]);
console.log(result);
// [ [ 331991.4287047193, 7392429.793622222 ],
//  [ 332060.80596672115, 7392373.411801645 ],
//  [ 332071.60244720604, 7392363.189180976 ] ]

multilinestring

const ptolemyReproject = require('ptolemy-reproject');
 
//ptolemyReproject.multilinestring(sourceCRS, toCRS, multilinestringCoordinate);
const result = ptolemyReproject.multilinestring(4326, 32723, [
  [[-46.64624065160751, -23.569855558195446], [-46.645567417144775, -23.570371829788982]],
  [[-46.645567417144775, -23.570371829788982], [-46.645462810993195, -23.570465250146203]],
]);
console.log(result);
// [ [ [ 331991.4287047193, 7392429.793622222 ],
//    [ 332060.80596672115, 7392373.411801645 ] ],
//  [ [ 332060.80596672115, 7392373.411801645 ],
//    [ 332071.60244720604, 7392363.189180976 ] ] ]

polygon

const ptolemyReproject = require('ptolemy-reproject');
 
//ptolemyReproject.polygon(sourceCRS, toCRS, polygonCoordinate);
const result = ptolemyReproject.polygon(4326, 32722, [
  [
    [-50.77056884765625, -21.13062153436313],
    [-50.9271240234375, -21.12293562133021],
    [-50.83648681640625, -21.19465530313863],
    [-50.77056884765625, -21.13062153436313],
  ],
]);
console.log(result);
// [ [ [ 523823.74799737247, 7663378.812094709 ],
//    [ 507567.6962134191, 7664244.906816781 ],
//    [ 516971.61788843677, 7656300.323619341 ],
//    [ 523823.74799737247, 7663378.812094709 ] ] ]

multipolygon

const ptolemyReproject = require('ptolemy-reproject');
 
//ptolemyReproject.multipolygon(sourceCRS, toCRS, multipolygonCoordinate);
const result = ptolemyReproject.multipolygon(4326, 32722, [
  [
    [
      [-50.77056884765625, -21.13062153436313],
      [-50.9271240234375, -21.12293562133021],
      [-50.83648681640625, -21.19465530313863],
      [-50.77056884765625, -21.13062153436313],
    ],
  ],
  [
    [
      [-50.9930419921875, -21.971066459686128],
      [-51.16607666015625, -22.039821650237034],
      [-51.0260009765625, -22.06527806776582],
      [-50.9930419921875, -21.971066459686128],
    ],
  ],
]);
console.log(result);
// [[[
//   [523823.74799737247, 7663378.812094709],
//   [507567.6962134191, 7664244.906816781],
//   [516971.61788843677, 7656300.323619341],
//   [523823.74799737247, 7663378.812094709]]],
// [[
//   [500718.3570432642, 7570375.557733057],
//   [482862.1996588615, 7562756.012907166],
//   [497317.38720489846, 7559947.418020568],
//   [500718.3570432642, 7570375.557733057],
//   ]]];

Testing

npm test