域名不作网站用途,指数函数图像及性质,神马网站快速排名软件,互联网建造公司有哪些零、背景
这几天在选样点#xff0c;发现GEE有强大的ui功能#xff0c;于是应用在我的工作上。
下述代码实现了几个功能#xff1a;
①用户可以自己勾勒多边形#xff0c;随后程序会按面积比例在多边形中自动生成样点#xff0c;同时根据改多边形的区域生成区域平均月N…零、背景
这几天在选样点发现GEE有强大的ui功能于是应用在我的工作上。
下述代码实现了几个功能
①用户可以自己勾勒多边形随后程序会按面积比例在多边形中自动生成样点同时根据改多边形的区域生成区域平均月NDVI曲线可以实现选取多个多边形。
②设置【Export】ui按钮将已选的多边形和生成的样点以shp文件形式导出。
③如果对刚才画的多边形不满意点击【Delete】ui按钮即可将最近画的一个多边形以及其上生成的样点删除。 一、录了个小视频先来感受一下效果吧 用户自画多边形 按面积比例在多边形中自动生成样点导出多边形 二、代码
GEE链接https://code.earthengine.google.com/31d8edcd71f7b5d27201b88fc46c1e05
/*----------- --------------Sample
------------- --------------*/
// 创建地图
var map1 ui.Map().setOptions(Hybrid).setZoom(4);
var map2 ui.Map().setOptions(Hybrid).setZoom(4);// map1 监听 map2 的缩放级别变化map2 监听 map1 的缩放级别变
map1.onChangeZoom(function(zoom){zoom parseInt(zoom); // 转换为整数类型map2.setZoom(zoom);
});map2.onChangeZoom(function(zoom){zoom parseInt(zoom);map1.setZoom(zoom);
});// 当在一个地图上平移时其他两个地图会同步平移。
var linker ui.Map.Linker([map1, map2], change-center);// 添加图层到地图面板
map1.centerObject(aoi,8);map1.addLayer(lucc_img.clip(aoi), luccVis, year_Land Cover Map);//lucc_img可替换为自己的可视化数据// 获取MODIS影像集合
var modisCollection ee.ImageCollection(MODIS/061/MOD13Q1).filterBounds(aoi).filterDate(year-01-01, year-12-31); // 修正日期范围// 创建时间序列面板
var chartPanel ui.Panel({style: {width: 34%}
});// 创建一个空的 FeatureCollection 来存储样本polygon
var polygonsCollection ee.FeatureCollection([]);
// 创建一个空的 FeatureCollection 来存储样本points
var pointsCollection ee.FeatureCollection([]);
var numPoints; // 全局变量// 创建region 的NDVI时间序列图表
var plotNDVI function(geometry, title) {// 选择NDVI波段并将值乘以0.0001var adjustedModisCollection modisCollection.map(function(image) {return image.reproject(EPSG:4326).select(NDVI).multiply(0.0001).copyProperties(image, [system:time_start]);});// ee.Reducer.mean() 计算该区域内像素值的平均值var timeSeries ui.Chart.image.series({imageCollection: adjustedModisCollection,region: geometry,reducer: ee.Reducer.mean(),scale: 250,xProperty: system:time_start}).setOptions({title: title,vAxis: {title: NDVI},hAxis: {title: Date},lineWidth: 1,pointSize: 3});chartPanel.clear();chartPanel.add(timeSeries);
};// 导出函数
function exportPolygons_points() {// 检查 FeatureCollection 是否包含元素if (polygonsCollection.size().getInfo() 0) {// 导出 FeatureCollection 到 Google Drive 为 SHP 格式Export.table.toDrive({collection: polygonsCollection,description: Exported_Polygons,fileFormat: SHP // 指定文件格式为 SHP});print(Exporting polygons to Google Drive as SHP...);} else {print(No polygons to export.);}if (pointsCollection.size().getInfo() 0) {// 导出 FeatureCollection 到 Google Drive 为 SHP 格式Export.table.toDrive({collection: pointsCollection,description: Exported_Points,fileFormat: SHP // 指定文件格式为 SHP});print(Exporting points to Google Drive as SHP...);
} else {print(No points to export.);
}
}
// 创建导出按钮
var exportPolygons_points_Button ui.Button({label: Export Polygons/points,onClick: exportPolygons_points
});
// 将导出按钮添加到 map2
map2.add(exportPolygons_points_Button);// Function to add drawing tools to the map
function addDrawingTools(map, mapTitle) {var drawingTools map.drawingTools();drawingTools.addLayer([], geometry);drawingTools.setShape(polygon);drawingTools.draw();// Draw a polygonfunction onClickToDrawPoint(){var polygon drawingTools.layers().get(0).getEeObject(); // Get the point drawn by the userdrawingTools.layers().reset(); // Clear the drawing toolsvar areaInMeters polygon.area();print(areaInMeters,areaInMeters);// Create a feature with the coordinates as propertiesvar polygon_feature ee.Feature(polygon);// Add the new point to the points collectionpolygonsCollection polygonsCollection.merge(ee.FeatureCollection([polygon_feature])); // Merge the feature into the collection//print(polygonsCollection,polygonsCollection)// Calculate the number of random points based on the areanumPoints areaInMeters.divide(1572500).ceil(); // Area / 1572500 (in square meters)不加var 即更新全局变量 numPoints而不是定义局部变量print(numPoints, numPoints);// Generate random points within the polygonvar randomPoints ee.FeatureCollection.randomPoints(polygon_feature.geometry(), numPoints);//print(randomPoints,randomPoints);pointsCollection pointsCollection.merge(ee.FeatureCollection(randomPoints)); // Merge the feature into the collection//print(pointsCollection,pointsCollection)// Update the map with the new points collectionmap1.layers().set(4, ui.Map.Layer(polygonsCollection, {color: FF0000}, Sample Polygons));map2.layers().set(0, ui.Map.Layer(polygonsCollection, {color: FF0000}, Sample Polygons));map1.layers().set(5, ui.Map.Layer(pointsCollection, {color: 000000}, Sample Points));map2.layers().set(1, ui.Map.Layer(pointsCollection, {color: 000000}, Sample Points));// Redraw the NDVI chart (or any other chart youre displaying)plotNDVI(polygon_feature, mapTitle);drawingTools.draw();}drawingTools.onDraw(onClickToDrawPoint); // Enable drawing tools
}// Add drawing tools and delete button
addDrawingTools(map1, Click map 1 and add polygons!);
addDrawingTools(map2, Click map 2 and add polygons!);
addDeleteButton(); // Add the delete button to the UI// Function to add a delete button to remove the last drawn Polygon/Points
function addDeleteButton() {// Create the delete buttonvar deleteButton ui.Button({label: Delete Last Polygon/Points,onClick: function() {// Delete last polygonif (polygonsCollection.size().getInfo() 0) {// Get the index of the last featurevar lastPolygon polygonsCollection.toList(polygonsCollection.size()).get(-1); // Get the last polygon// Remove the last polygon by filtering it outpolygonsCollection polygonsCollection.filter(ee.Filter.neq(system:index, ee.Feature(lastPolygon).get(system:index)));print(Last polygon deleted);} else {print(No polygon to delete); // Print if no polygon exists}// Delete last pointsif (pointsCollection.size().getInfo() 0) {// Calculate the size of the collectionvar collectionSize pointsCollection.size();// Convert FeatureCollection to listvar pointsList pointsCollection.toList(collectionSize);//var n numPoints // assuming numPoints is defined elsewhere//print(numPoints2,numPoints)// Slice the list to exclude the last n pointsvar slicedPointsList pointsList.slice(0, ee.Number(collectionSize).subtract(numPoints)); // Slice to remove last numPoints points// Convert the sliced list back to a FeatureCollectionpointsCollection ee.FeatureCollection(slicedPointsList);// Update the map with the new polygon/points collectionmap1.layers().set(4, ui.Map.Layer(polygonsCollection, {color: FF0000}, Sample Polygons));map2.layers().set(0, ui.Map.Layer(polygonsCollection, {color: FF0000}, Sample Polygons));map1.layers().set(5, ui.Map.Layer(pointsCollection, {color: 000000}, Sample Points));map2.layers().set(1, ui.Map.Layer(pointsCollection, {color: 000000}, Sample Points));print(Last numPoints.getInfo() points deleted);} else {print(No points to delete.);}}});// Add the delete button to map2map2.add(deleteButton);
}// 创建水平分割面板宽度为整个用户界面的66%其中 map1 和 map2 分别位于左侧和右侧
var split1 ui.Panel(ui.SplitPanel({firstPanel: map1,secondPanel: map2,orientation: horizontal,wipe: false,
}), null, {width: 66%, height:100%});// 创建水平分割面板宽度为整个用户界面的34%其中 chartPanel 位于map1和map2的右侧
var split2 ui.Panel(ui.SplitPanel({firstPanel: split1,secondPanel: chartPanel,orientation: horizontal,wipe: false,
}), null, {width: 100%, height: 100%});map2.setControlVisibility(false);//设置 map2 地图的控制面板如缩放、平移、图层选择等控制元素不显示
ui.root.clear(); // 清空当前用户界面上的所有内容
ui.root.insert(0, split2); // 将新的布局 split2 插入到用户界面的根容器中位置索引为 0即第一个位置
完结撒花
