web前端利用turf.js生成等值线、等值面

时间：2022-02-21 04:10:09

样例如下：

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">

<head>

    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

    <title>等值线的生成</title>

    <link href="Script/leaflet/leaflet.css" rel="stylesheet" />

    <style>

        #map

        {

            height: 2000px;

            width: 1500px;

        }

    </style>

    <script src="Script/leaflet/leaflet.js"></script>

    <script src="Script/leaflet/leaflet.ChineseTmsProviders.js"></script>

    <script src='https://npmcdn.com/@turf/turf/turf.min.js'></script>

</head>

<body>

    <div id="map"></div>

</body>

    <script>

        var normalm = L.tileLayer.chinaProvider('TianDiTu.Normal.Map', {

            maxZoom: 18,

            minZoom: 1

        }),

            normala = L.tileLayer.chinaProvider('TianDiTu.Normal.Annotion', {

                maxZoom: 18,

                minZoom: 1

            }),

            imgm = L.tileLayer.chinaProvider('TianDiTu.Satellite.Map', {

                maxZoom: 18,

                minZoom: 1

            }),

            imga = L.tileLayer.chinaProvider('TianDiTu.Satellite.Annotion', {

                maxZoom: 18,

                minZoom: 1

            });

        var normal = L.layerGroup([normalm, normala]);

        image = L.layerGroup([imgm, imga]);

        var baseLayers = {

            "地图": normal,

            "影像": image,

        }

        var overlayLayers = {

            "图": normal,

            "像": image,

        }

        var map = L.map("map", {

            center: [31.59, 120.29],

            zoom: 12,

            layers: [normal],

            zoomControl: false

        });

        // 创建等值线区域

        var extent = [0, 30, 20, 50];

        var cellWidth = 100;

        var pointGrid = turf.pointGrid(extent, cellWidth, { units: 'miles' });

        for (var i = 0; i < pointGrid.features.length; i++) {

            pointGrid.features[i].properties.temperature = Math.random() * 10;

        }

        console.log(pointGrid.features.length);

        //等值线的级数

        var breaks = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10];

        var lines = turf.isolines(pointGrid, breaks, { zProperty: 'temperature' });

        //设置颜色

        var myStyle = {

            "color": "#ff7800",

            "weight": 5,

            "opacity": 0.65

        };

        //进行平滑处理

            var _lFeatures = lines.features;

            for(var i=0;i<_lFeatures.length;i++){

                var _coords = _lFeatures[i].geometry.coordinates;

                var _lCoords = [];

                for(var j=0;j<_coords.length;j++){

                    var _coord = _coords[j];

                    var line = turf.lineString(_coord);

                    var curved = turf.bezierSpline(line);

                    _lCoords.push(curved.geometry.coordinates);

                }

                _lFeatures[i].geometry.coordinates = _lCoords;

            }

        //geojson数据读取

        L.geoJSON(lines, {

            style: myStyle

        }).addTo(map);

    </script>

</html>

原文地址：https://blog.csdn.net/weixin_40184249/article/details/81198282

另外一个文章地址：http://www.cnblogs.com/naaoveGIS/p/6142226.html

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