这次使用到的工具：
ui.Chart.image.regions(image, regions, reducer, scale, seriesProperty, xLabels)
和上次的.byregions不同下面黄色部分
Generates a Chart from an image. Extracts and plots the value of each band in one or more regions.
- X-axis = Band labeled by xProperty (default: band name).
- Y-axis = Reducer output.
- Series = Region labeled by seriesProperty (default: 'system:index').
系列 = 由 seriesProperty 标记的区域（默认值：'system:index'）属性值不同，主要是标记的点来进行属性添加的。
Returns a chart.
Arguments:
image (Image):
Image to extract band values from.
regions (Feature|FeatureCollection|Geometry|List<Feature>|List<Geometry>, optional):
Regions to reduce. Defaults to the image's footprint.
reducer (Reducer, optional):筛选器产生一个单个波段的值作为Y轴的值
Reducer that generates the value(s) for the y-axis. Must return a single value per band.
scale (Number, optional):
The pixel scale in meters.
seriesProperty (String, optional):
用作图例中每个区域标签的属性。默认为“系统：索引”
Property to be used as the label for each region in the legend. Defaults to 'system:index'.
xLabels (List<Object>, optional):
A list of labels used for bands on the x-axis. Must have the same number of elements as the image bands. If omitted, bands will be labeled with their names. If the labels are numeric (e.g. wavelengths), x-axis will be continuous.
Returns: ui.Chart
看代码：
var landsat8Toa = ee.ImageCollection('LANDSAT/LC08/C01/T1_TOA'); //设定一个变量三个颜色，一会分别作为三个点显示的颜色 var COLOR = { PARK: 'ff0000', FARM: '0000ff', URBAN: '00ff00' }; // 设置三个你想知道的点，并且把label作为其中的legend图例 Three known locations. var park = ee.Feature( ee.Geometry.Point(-99.25260, 19.32235), {'label': 'park'}); var farm = ee.Feature( ee.Geometry.Point(-99.08992, 19.27868), {'label': 'farm'}); var urban = ee.Feature( ee.Geometry.Point(-99.21135, 19.31860), {'label': 'urban'}); //设置点的集合作为矢量点图层 var mexicoPoints = ee.FeatureCollection([park, farm, urban]); landsat8Toa = landsat8Toa.filterBounds(mexicoPoints); //选取第一幅影像 var mexicoImage = ee.Image(landsat8Toa.first()); // 选取波段可以这么选省下一个个写，Select bands B1 to B7. mexicoImage = mexicoImage.select(['B[1-7]']); //这个就是根据你的矢量无论是点还是面还是线，一般都是通过region来进行图形的显示 var bandChart = ui.Chart.image.regions({ image: mexicoImage, regions: mexicoPoints, scale: 30, seriesProperty: 'label' }); //设置你的图像显示，本次选择是线性图 bandChart.setChartType('LineChart'); //设置你的图上的属性，设置横纵轴和标题，线宽和点的大小 bandChart.setOptions({ title: 'Landsat 8 TOA band values at three points near Mexico City', hAxis: { title: 'Band' }, vAxis: { title: 'Reflectance' }, lineWidth: 1, pointSize: 4, series: { 0: {color: COLOR.PARK}, 1: {color: COLOR.FARM}, 2: {color: COLOR.URBAN} } }); // From: https://landsat.usgs.gov/what-are-best-spectral-bands-use-my-study最佳光谱值通过官网提供的，自己可以查询 var wavelengths = [.44, .48, .56, .65, .86, 1.61, 2.2]; //这个是光谱的值图像显示seriesProperty就是你的图例，label对应的键值 var spectraChart = ui.Chart.image.regions({ image: mexicoImage, regions: mexicoPoints, scale: 30, seriesProperty: 'label', xLabels: wavelengths }); spectraChart.setChartType('LineChart'); spectraChart.setOptions({ title: 'Landsat 8 TOA spectra at three points near Mexico City', hAxis: { title: 'Wavelength (micrometers)'//（）中代表你的单位 }, vAxis: { title: 'Reflectance' }, lineWidth: 1, pointSize: 4, series: { 0: {color: COLOR.PARK}, 1: {color: COLOR.FARM}, 2: {color: COLOR.URBAN} } }); //最后打印两个图表 print(bandChart); print(spectraChart); Map.addLayer(park, {color: COLOR.PARK}); Map.addLayer(farm, {color: COLOR.FARM}); Map.addLayer(urban, {color: COLOR.URBAN}); Map.setCenter(-99.25260, 19.32235, 11);
三个点的信息分别代表市区、城中心和农场
