Feature 和 FeatureCollection 图表

ui.Chart.feature 模块包含一组用于从 Feature 和 FeatureCollection 对象渲染图表的函数。所选函数决定了图表中数据的排列方式，即定义 x 轴和 y 轴值以及定义系列的是什么。请参考以下函数说明和示例，确定最适合您用途的函数和图表类型。

图表函数

请参考以下图表，直观了解每个函数如何在图表中排列特征及其属性；即，哪些元素定义了 x 值、y 值和系列。

ui.Chart.feature.byFeature

特征会按所选属性的值沿 x 轴绘制。系列由属性名称列表定义，其值会沿 y 轴绘制。

ui.Chart.feature.byProperty

特征属性按名称沿 x 轴绘制；给定属性的值沿 y 轴绘制。系列是按所选属性的值标记的地图项。

ui.Chart.feature.groups

特征会按所选属性的值沿 x 轴绘制。系列由给定媒体资源的唯一值定义。Y 轴位置由给定属性的值定义。

ui.Chart.feature.histogram

所选属性值的频率直方图。

• X 轴：所选属性值的直方图分桶
• Y 轴：符合每个直方图分桶条件的特征的频率

示例数据

以下示例依赖于由三个生态区域地图项组成的 FeatureCollection，其中包含用于描述气候常态的属性。

了解示例数据的创建方式

Code Editor (JavaScript)

// Define three representative ecoregions in the USA.
var desert = ee.Feature(
    ee.Geometry.Rectangle(-109.21, 31.42, -108.3, 32.03),
    {label: 'Desert', value: 0});

var forest = ee.Feature(
    ee.Geometry.Rectangle(-122.73, 43.45, -122.28, 43.91),
    {label: 'Forest', value: 1});

var grassland = ee.Feature(
    ee.Geometry.Rectangle(-101.81, 41.7, -100.53, 42.51),
    {label: 'Grassland', value: 2});

// Combine features into a feature collection.
var ecoregions = ee.FeatureCollection([desert, forest, grassland]);

// Load PRISM climate normals image collection; convert images to bands.
var normClim = ee.ImageCollection('OREGONSTATE/PRISM/Norm81m').toBands();

// Summarize climate normals for each ecoregion feature as a set or properties.
ecoregions = normClim.reduceRegions(
    {collection: ecoregions, reducer: ee.Reducer.mean(), scale: 5e4});

// Add a property for whether January temperature is warm or not.
ecoregions = ecoregions.map(function(ecoregion) {
  return ecoregion.set('warm', ee.Number(ecoregion.get('01_tmean')).gt(0));
});

ui.Chart.feature.byFeature

柱形图

地图项沿 X 轴绘制，并标注所选属性的值。系列由由属性名称列表定义的邻近列表示，其值沿 y 轴绘制。

Code Editor (JavaScript)

// Import the example feature collection.
var ecoregions = ee.FeatureCollection('projects/google/charts_feature_example');

// Define the chart and print it to the console.
var chart =
    ui.Chart.feature
        .byFeature({
          features: ecoregions.select('[0-9][0-9]_tmean|label'),
          xProperty: 'label',
        })
        .setSeriesNames([
          'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct',
          'Nov', 'Dec'
        ])
        .setChartType('ColumnChart')
        .setOptions({
          title: 'Average Monthly Temperature by Ecoregion',
          hAxis:
              {title: 'Ecoregion', titleTextStyle: {italic: false, bold: true}},
          vAxis: {
            title: 'Temperature (°C)',
            titleTextStyle: {italic: false, bold: true}
          },
          colors: [
            '604791', '1d6b99', '39a8a7', '0f8755', '76b349', 'f0af07',
            'e37d05', 'cf513e', '96356f', '724173', '9c4f97', '696969'
          ]
        });
print(chart);

条形图

地图项会沿着 y 轴绘制，并标注所选属性的值。系列由相邻的条柱表示，这些条柱由属性名称列表定义，其值沿 x 轴绘制。

Code Editor (JavaScript)

// Import the example feature collection.
var ecoregions = ee.FeatureCollection('projects/google/charts_feature_example');

// Define the chart and print it to the console.
var chart =
    ui.Chart.feature
        .byFeature({
          features: ecoregions.select('[0-9][0-9]_tmean|label'),
          xProperty: 'label',
        })
        .setSeriesNames([
          'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct',
          'Nov', 'Dec'
        ])
        .setChartType('BarChart')
        .setOptions({
          title: 'Average Monthly Temperature by Ecoregion',
          hAxis: {
            title: 'Temperature (°C)',
            titleTextStyle: {italic: false, bold: true}
          },
          vAxis:
              {title: 'Ecoregion', titleTextStyle: {italic: false, bold: true}},
          colors: [
            '604791', '1d6b99', '39a8a7', '0f8755', '76b349', 'f0af07',
            'e37d05', 'cf513e', '96356f', '724173', '9c4f97', '696969'
          ]
        });
print(chart);

堆叠柱形图

绝对

地图项沿 X 轴绘制，并标注所选属性的值。系列由堆叠的列表示，这些列由属性名称列表定义，其值沿 y 轴绘制为累计系列总和。

Code Editor (JavaScript)

// Import the example feature collection.
var ecoregions = ee.FeatureCollection('projects/google/charts_feature_example');

// Define the chart and print it to the console.
var chart =
    ui.Chart.feature
        .byFeature({
          features: ecoregions.select('[0-9][0-9]_ppt|label'),
          xProperty: 'label'
        })
        .setSeriesNames([
          'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct',
          'Nov', 'Dec'
        ])
        .setChartType('ColumnChart')
        .setOptions({
          title: 'Average Monthly Precipitation by Ecoregion',
          hAxis:
              {title: 'Ecoregion', titleTextStyle: {italic: false, bold: true}},
          vAxis: {
            title: 'Precipitation (mm)',
            titleTextStyle: {italic: false, bold: true}
          },
          colors: [
            '604791', '1d6b99', '39a8a7', '0f8755', '76b349', 'f0af07',
            'e37d05', 'cf513e', '96356f', '724173', '9c4f97', '696969'
          ],
          isStacked: 'absolute'
        });
print(chart);

相对

地图项沿 X 轴绘制，并标注所选属性的值。系列由由属性名称列表定义的堆叠列表示，其值沿 y 轴绘制为相对于总和系列的百分比。

Code Editor (JavaScript)

// Import the example feature collection.
var ecoregions = ee.FeatureCollection('projects/google/charts_feature_example');

// Define the chart and print it to the console.
var chart =
    ui.Chart.feature
        .byFeature({
          features: ecoregions.select('[0-9][0-9]_ppt|label'),
          xProperty: 'label'
        })
        .setSeriesNames([
          'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct',
          'Nov', 'Dec'
        ])
        .setChartType('ColumnChart')
        .setOptions({
          title: 'Average Monthly Precipitation by Ecoregion',
          hAxis:
              {title: 'Ecoregion', titleTextStyle: {italic: false, bold: true}},
          vAxis: {
            title: 'Precipitation (mm)',
            titleTextStyle: {italic: false, bold: true}
          },
          colors: [
            '604791', '1d6b99', '39a8a7', '0f8755', '76b349', 'f0af07',
            'e37d05', 'cf513e', '96356f', '724173', '9c4f97', '696969'
          ],
          isStacked: 'percent'
        });
print(chart);

散点图

地图项沿 X 轴绘制，并标注所选属性的值。系列由由属性名称列表定义的点表示，其值沿 y 轴绘制。

Code Editor (JavaScript)

// Import the example feature collection.
var ecoregions = ee.FeatureCollection('projects/google/charts_feature_example');

// Define the chart and print it to the console.
var chart =
    ui.Chart.feature
        .byFeature({
          features: ecoregions,
          xProperty: 'label',
          yProperties: ['01_tmean', '07_tmean']
        })
        .setSeriesNames(['Jan', 'Jul'])
        .setChartType('ScatterChart')
        .setOptions({
          title: 'Average Monthly Temperature by Ecoregion',
          hAxis:
              {title: 'Ecoregion', titleTextStyle: {italic: false, bold: true}},
          vAxis: {
            title: 'Temperature (°C)',
            titleTextStyle: {italic: false, bold: true}
          },
          pointSize: 10,
          colors: ['1d6b99', 'cf513e'],
        });
print(chart);

组合图表

地图项沿 X 轴绘制，并标注所选属性的值。系列由点和列表示，这些点和列由属性名称列表定义，其值沿 y 轴绘制。此图表使用两个轴和系列专用样式创建而成。

Code Editor (JavaScript)

// Import the example feature collection.
var ecoregions = ee.FeatureCollection('projects/google/charts_feature_example');

// Define the chart and print it to the console.
var chart =
    ui.Chart.feature
        .byFeature({
          features: ecoregions,
          xProperty: 'label',
          yProperties: ['06_ppt', '06_tmean']
        })
        .setSeriesNames(['Precipitation', 'Temperature'])
        .setChartType('ColumnChart')
        .setOptions({
          title: 'Average June Temperature and Precipitation by Ecoregion',
          series: {
            0: {targetAxisIndex: 1, type: 'bar', color: '1d6b99'},
            1: {
              targetAxisIndex: 0,
              type: 'line',
              lineWidth: 0,
              pointSize: 10,
              color: 'e37d05'
            }
          },
          hAxis:
              {title: 'Ecoregion', titleTextStyle: {italic: false, bold: true}},
          vAxes: {
            0: {
              title: 'Temperature (°C)',
              baseline: 0,
              titleTextStyle: {italic: false, bold: true, color: 'e37d05'}
            },
            1: {
              title: 'Precipitation (mm)',
              titleTextStyle: {italic: false, bold: true, color: '1d6b99'}
            },
          },
          bar: {groupWidth: '40%'},
        });
print(chart);

ui.Chart.feature.byProperty

示例设置

ui.Chart.feature.byProperty 函数接受一个字典，您可以通过为 x 轴上的属性名称分配数值来控制其标签和顺序。以下直角坐标系图表使用此选项来设置月份标签，并按时间顺序对月份名称进行排序，以显示每月平均降水量。

柱形图

特征属性沿 x 轴绘制，并按字典输入进行标记和排序；给定属性的值沿 y 轴绘制。系列是指由列表示的房源，并以所选房源的值标记。如需转换为条形图，请使用 .setChartType('BarChart')。

Code Editor (JavaScript)

// Import the example feature collection.
var ecoregions = ee.FeatureCollection('projects/google/charts_feature_example');

// Define a dictionary that associates property names with values and labels.
var precipInfo = {
  '01_ppt': {v: 1, f: 'Jan'},
  '02_ppt': {v: 2, f: 'Feb'},
  '03_ppt': {v: 3, f: 'Mar'},
  '04_ppt': {v: 4, f: 'Apr'},
  '05_ppt': {v: 5, f: 'May'},
  '06_ppt': {v: 6, f: 'Jun'},
  '07_ppt': {v: 7, f: 'Jul'},
  '08_ppt': {v: 8, f: 'Aug'},
  '09_ppt': {v: 9, f: 'Sep'},
  '10_ppt': {v: 10, f: 'Oct'},
  '11_ppt': {v: 11, f: 'Nov'},
  '12_ppt': {v: 12, f: 'Dec'}
};

// Organize property information into objects for defining x properties and
// their tick labels.
var xPropValDict = {};  // Dictionary to codify x-axis property names as values.
var xPropLabels = [];   // Holds dictionaries that label codified x-axis values.
for (var key in precipInfo) {
  xPropValDict[key] = precipInfo[key].v;
  xPropLabels.push(precipInfo[key]);
}

// Define the chart and print it to the console.
var chart = ui.Chart.feature
                .byProperty({
                  features: ecoregions,
                  xProperties: xPropValDict,
                  seriesProperty: 'label'
                })
                .setChartType('ColumnChart')
                .setOptions({
                  title: 'Average Ecoregion Precipitation by Month',
                  hAxis: {
                    title: 'Month',
                    titleTextStyle: {italic: false, bold: true},
                    ticks: xPropLabels
                  },
                  vAxis: {
                    title: 'Precipitation (mm)',
                    titleTextStyle: {italic: false, bold: true}
                  },
                  colors: ['f0af07', '0f8755', '76b349'],
                });
print(chart);

折线图

特征属性沿 x 轴绘制，并按字典输入进行标记和排序；给定属性的值沿 y 轴绘制。系列是指由线条表示的地图项，并以所选属性的值标记。

Code Editor (JavaScript)

// Import the example feature collection.
var ecoregions = ee.FeatureCollection('projects/google/charts_feature_example');

// Define a dictionary that associates property names with values and labels.
var precipInfo = {
  '01_ppt': {v: 1, f: 'Jan'},
  '02_ppt': {v: 2, f: 'Feb'},
  '03_ppt': {v: 3, f: 'Mar'},
  '04_ppt': {v: 4, f: 'Apr'},
  '05_ppt': {v: 5, f: 'May'},
  '06_ppt': {v: 6, f: 'Jun'},
  '07_ppt': {v: 7, f: 'Jul'},
  '08_ppt': {v: 8, f: 'Aug'},
  '09_ppt': {v: 9, f: 'Sep'},
  '10_ppt': {v: 10, f: 'Oct'},
  '11_ppt': {v: 11, f: 'Nov'},
  '12_ppt': {v: 12, f: 'Dec'}
};

// Organize property information into objects for defining x properties and
// their tick labels.
var xPropValDict = {};  // Dictionary to codify x-axis property names as values.
var xPropLabels = [];   // Holds dictionaries that label codified x-axis values.
for (var key in precipInfo) {
  xPropValDict[key] = precipInfo[key].v;
  xPropLabels.push(precipInfo[key]);
}

// Define the chart and print it to the console.
var chart = ui.Chart.feature
                .byProperty({
                  features: ecoregions,
                  xProperties: xPropValDict,
                  seriesProperty: 'label'
                })
                .setChartType('ScatterChart')
                .setOptions({
                  title: 'Average Ecoregion Precipitation by Month',
                  hAxis: {
                    title: 'Month',
                    titleTextStyle: {italic: false, bold: true},
                    ticks: xPropLabels
                  },
                  vAxis: {
                    title: 'Precipitation (mm)',
                    titleTextStyle: {italic: false, bold: true}
                  },
                  colors: ['f0af07', '0f8755', '76b349'],
                  lineSize: 5,
                  pointSize: 0
                });
print(chart);

面积图

特征属性沿 x 轴绘制，并按字典输入进行标记和排序；给定属性的值沿 y 轴绘制。系列是指由线条和阴影区域表示的地图项，并通过所选属性的值进行标记。

Code Editor (JavaScript)

// Import the example feature collection.
var ecoregions = ee.FeatureCollection('projects/google/charts_feature_example');

// Define a dictionary that associates property names with values and labels.
var precipInfo = {
  '01_ppt': {v: 1, f: 'Jan'},
  '02_ppt': {v: 2, f: 'Feb'},
  '03_ppt': {v: 3, f: 'Mar'},
  '04_ppt': {v: 4, f: 'Apr'},
  '05_ppt': {v: 5, f: 'May'},
  '06_ppt': {v: 6, f: 'Jun'},
  '07_ppt': {v: 7, f: 'Jul'},
  '08_ppt': {v: 8, f: 'Aug'},
  '09_ppt': {v: 9, f: 'Sep'},
  '10_ppt': {v: 10, f: 'Oct'},
  '11_ppt': {v: 11, f: 'Nov'},
  '12_ppt': {v: 12, f: 'Dec'}
};

// Organize property information into objects for defining x properties and
// their tick labels.
var xPropValDict = {};  // Dictionary to codify x-axis property names as values.
var xPropLabels = [];   // Holds dictionaries that label codified x-axis values.
for (var key in precipInfo) {
  xPropValDict[key] = precipInfo[key].v;
  xPropLabels.push(precipInfo[key]);
}

// Define the chart and print it to the console.
var chart = ui.Chart.feature
                .byProperty({
                  features: ecoregions,
                  xProperties: xPropValDict,
                  seriesProperty: 'label'
                })
                .setChartType('AreaChart')
                .setOptions({
                  title: 'Average Ecoregion Precipitation by Month',
                  hAxis: {
                    title: 'Month',
                    titleTextStyle: {italic: false, bold: true},
                    ticks: xPropLabels
                  },
                  vAxis: {
                    title: 'Precipitation (mm)',
                    titleTextStyle: {italic: false, bold: true}
                  },
                  colors: ['f0af07', '0f8755', '76b349'],
                  lineSize: 5,
                  pointSize: 0,
                  curveType: 'function'
                });
print(chart);

饼图

饼图是一种地图项，每个切片都是一个房源标签，其值会转换为构成饼图的房源的所有值总和的百分比。

Code Editor (JavaScript)

// Import the example feature collection.
var ecoregions = ee.FeatureCollection('projects/google/charts_feature_example');

// Subset the forest ecoregion feature and select the monthly precipitation
// properties, rename them as abbreviated months.
var thisForest = ecoregions.filter(ee.Filter.eq('label', 'Forest'))
                     .select(Object.keys(precipInfo), [
                       'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug',
                       'Sep', 'Oct', 'Nov', 'Dec'
                     ]);

// Define the chart and print it to the console.
var chart = ui.Chart.feature
                .byProperty({
                  features: thisForest,
                  xProperties: [
                    'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug',
                    'Sep', 'Oct', 'Nov', 'Dec'
                  ]
                })
                .setChartType('PieChart')
                .setOptions({
                  title: 'Average Monthly Precipitation for Forest Ecoregion',
                  colors: [
                    '604791', '1d6b99', '39a8a7', '0f8755', '76b349', 'f0af07',
                    'e37d05', 'cf513e', '96356f', '724173', '9c4f97', '696969'
                  ]
                });
print(chart);

圆环图

通过设置 pieHole 图表选项，将饼图转换为甜甜圈图；在大多数图表中，数字介于 0.4 到 0.6 之间效果最佳。

Code Editor (JavaScript)

// Import the example feature collection.
var ecoregions = ee.FeatureCollection('projects/google/charts_feature_example');

// Subset the forest ecoregion feature and select the monthly precipitation
// properties, rename them as abbreviated months.
var thisForest = ecoregions.filter(ee.Filter.eq('label', 'Forest'))
                     .select(Object.keys(precipInfo), [
                       'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug',
                       'Sep', 'Oct', 'Nov', 'Dec'
                     ]);

// Define the chart and print it to the console.
var chart = ui.Chart.feature
                .byProperty({
                  features: thisForest,
                  xProperties: [
                    'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug',
                    'Sep', 'Oct', 'Nov', 'Dec'
                  ]
                })
                .setChartType('PieChart')
                .setOptions({
                  title: 'Average Monthly Precipitation for Forest Ecoregion',
                  colors: [
                    '604791', '1d6b99', '39a8a7', '0f8755', '76b349', 'f0af07',
                    'e37d05', 'cf513e', '96356f', '724173', '9c4f97', '696969'
                  ],
                  pieHole: 0.4,
                });
print(chart);

ui.Chart.feature.groups

柱形图

地图项沿 X 轴绘制，并标注所选属性的值。系列由由给定属性的一组唯一值定义的列表示。Y 轴位置由给定属性的值定义。您可以通过将图表类型设置为 'ScatterChart' (.setChartType('ScatterChart')) 将此图表更改为散点图。或者，如果时间是 x 轴变量，您可能更喜欢使用折线图：.setChartType('LineChart')。

Code Editor (JavaScript)

// Import the example feature collection.
var ecoregions = ee.FeatureCollection('projects/google/charts_feature_example');

// Define the chart and print it to the console.
var chart =
    ui.Chart.feature
        .groups({
          features: ecoregions,
          xProperty: 'label',
          yProperty: '01_tmean',
          seriesProperty: 'warm'
        })
        .setSeriesNames(['Warm', 'Cold'])
        .setChartType('ColumnChart')
        .setOptions({
          title: 'Average January Temperature by Ecoregion',
          hAxis:
              {title: 'Ecoregion', titleTextStyle: {italic: false, bold: true}},
          vAxis: {
            title: 'Jan temp (°C)',
            titleTextStyle: {italic: false, bold: true}
          },
          bar: {groupWidth: '80%'},
          colors: ['cf513e', '1d6b99'],
          isStacked: true
        });
print(chart);

ui.Chart.feature.histogram

x 轴由所选属性的值范围的值分桶定义；y 轴是给定分桶中的元素数量。

Code Editor (JavaScript)

// Load PRISM climate normals image collection; convert images to bands.
var normClim = ee.ImageCollection('OREGONSTATE/PRISM/Norm81m').toBands();

// Make a point sample of climate variables for a region in western USA.
var region = ee.Geometry.Rectangle(-123.41, 40.43, -116.38, 45.14);
var climSamp = normClim.sample(region, 5000);

// Define the chart and print it to the console.
var chart =
    ui.Chart.feature
        .histogram({features: climSamp, property: '07_ppt', maxBuckets: 30})
        .setOptions({
          title: 'July Precipitation Distribution for NW USA',
          hAxis: {
            title: 'Precipitation (mm)',
            titleTextStyle: {italic: false, bold: true}
          },
          vAxis: {
            title: 'Pixel count',
            titleTextStyle: {italic: false, bold: true}
          },
          colors: ['1d6b99'],
          legend: {position: 'none'}
        });
print(chart);