Google earth engine（GEE）——平均气温计算并且显示直方图

美国三个州的平均气温计算并且显示直方图

 完整的图形是这样的

 这是我改了代码之后显示了一年十二个月的一个数据，坐标标签直接改成数字了

这里面有一个数据集OREGONSTATE/PRISM/Norm81m

用数据的时候可以引用这个文章

Daly, C., Halbleib, M., Smith, J.I., Gibson, W.P., Doggett, M.K., Taylor, G.H., Curtis, J., and Pasteris, P.A. 2008. Physiographically-sensitive mapping of temperature and precipitation across the conterminous United States. International Journal of Climatology, 28: 2031-2064

[Daly, C., J.I. Smith, and K.V. Olson. 2015. Mapping atmospheric moisture climatologies across the conterminous United States. PloS ONE 10(10):e0141140. doi:10.1371/journal.pone.0141140.

ee.Filter.notNull(properties)

如果所有命名属性不为空，则返回一个过滤器。

Returns a filter that passes if all the named properties are not null.

Arguments:

properties (List)过滤的值是一个列表，

Returns: Filter

这次主要用到的函数

ui.Chart.feature.byProperty(features, xProperties, seriesProperty)

Generates a Chart from a set of features. Plots property values of one or more features.

- X-axis = Property name, labeled by xProperties (default: all properties).

- Y-axis = Property value (must be numeric).

- Series = Features, labeled by seriesProperty (default: 'system:index').矢量属性值

All properties except seriesProperty are included on the x-axis by default.

默认情况下，除 seriesProperty 之外的所有属性都包含在 x 轴上。

Returns a chart.

Arguments:

features (Feature|FeatureCollection|List<Feature>):

The features to include in the chart.

xProperties (List<String>|Object|String, optional):

One of (1) a property to be plotted on the x-axis; (2) a list of properties to be plotted on the x-axis; or (3) a (property, label) dictionary specifying labels for properties to be used as values on the x-axis. If omitted, all properties will be plotted on the x-axis, labeled with their names.

seriesProperty (String, optional):

The name of the property used to label each feature in the legend. Defaults to 'system:index'.

Returns: ui.Chart

通过这个案例就是给出的三个州气温，明尼苏达州，德克萨斯州和佛罗里达州，1月，四月，7月和10月，如果想多个月份，只管在months加入元素即可

  

   

    

     

    
    

     

      //导入研究区
     
    
   

    

     

    
    

     

      var states = ee.FeatureCollection('TIGER/2018/States');
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      // 导入温度法线并将月份特征转换为波段。
     
    
   

    

     

    
    

     

      var normClim = ee.ImageCollection('OREGONSTATE/PRISM/Norm81m')
     
    
   

    

     

    
    

     

        .select(['tmean'])
     
    
   

    

     

    
    

     

        .toBands();
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      // 计算每个月每个州的平均值
     
    
   

    

     

    
    

     

      states = normClim.reduceRegions({
     
    
   

    

     

    
    

     
  collection: states,
     
    
   

    

     

    
    

     
  reducer: ee.Reducer.mean(),
     
    
   

    

     

    
    

     
  scale: 5e4})
     
    
   

    

     

    
    

     

        .filter(ee.Filter.notNull(['01_tmean']));
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      // 计算每个州1月和7月的温度均值然后给与这个州添加温度差值属性
     
    
   

    

     

    
    

     

      states = states.map(function(state) {
     
    
   

    

     

    
    

     
  var julyTemp = ee.Number(state.get('06_tmean'));
     
    
   

    

     

    
    

     
  var janTemp = ee.Number(state.get('01_tmean'));
     
    
   

    

     

    
    

     
  return state.set('seasonal_delta', julyTemp.subtract(janTemp));
     
    
   

    

     

    
    

     

      });
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      // 选择极端的州的天气，通过再次通过merge选取
     
    
   

    

     

    
    

     

      var extremeStates =
     
    
   

    

     

    
    

     

        states.limit(1, '01_tmean')                 // Coldest.
     
    
   

    

     

    
    

     

        .merge(states.limit(1, '07_tmean', false))  // Hottest.
     
    
   

    

     

    
    

     

        .merge(states.limit(1, 'seasonal_delta'));  // Least variation.
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      // 分别定义属性值在图表中，对应的月份和对应的温度所匹配
     
    
   

    

     

    
    

     

      // Define properties to chart.
     
    
   

    

     

    
    

     

      var months = {
     
    
   

    

     

    
    

     
  '01_tmean': 1,
     
    
   

    

     

    
    

     
  '02_tmean': 2,
     
    
   

    

     

    
    

     
  '03_tmean': 3,
     
    
   

    

     

    
    

     
  '04_tmean': 4,
     
    
   

    

     

    
    

     
  '05_tmean': 5,
     
    
   

    

     

    
    

     
  '06_tmean': 6,
     
    
   

    

     

    
    

     
  '07_tmean': 7,
     
    
   

    

     

    
    

     
  '08_tmean': 8,
     
    
   

    

     

    
    

     
  '09_tmean': 9,
     
    
   

    

     

    
    

     
  '10_tmean': 10,
     
    
   

    

     

    
    

     
  '11_tmean': 11,
     
    
   

    

     

    
    

     
  '12_tmean': 12
     
    
   

    

     

    
    

     

      };
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      // Prepare the chart.
     
    
   

    

     

    
    

     

      var extremeTempsChart =
     
    
   

    

     

    
    

     

        ui.Chart.feature.byProperty(extremeStates, months, 'NAME')
     
    
   

    

     

    
    

     

          .setChartType('LineChart')
     
    
   

    

     

    
    

     

          .setOptions({
     
    
   

    

     

    
    

     
      title: 'Average Temperatures in U.S. States',
     
    
   

    

     

    
    

     
      hAxis: {
     
    
   

    

     

    
    

     
        title: 'Month',
     
    
   

    

     

    
    

     
        ticks: [{v: months['01_tmean'], f: 'January'},
     
    
   

    

     

    
    

     

                      {v: months['02_tmean'], f: '2'},
     
    
   

    

     

    
    

     

                      {v: months['03_tmean'], f: '3'},
     
    
   

    

     

    
    

     

                      {v: months['04_tmean'], f: 'April'},
     
    
   

    

     

    
    

     

                      {v: months['05_tmean'], f: '5'},
     
    
   

    

     

    
    

     

                      {v: months['06_tmean'], f: '6'},
     
    
   

    

     

    
    

     

                      {v: months['07_tmean'], f: 'July'},                
     
    
   

    

     

    
    

     

                      {v: months['08_tmean'], f: '8'},
     
    
   

    

     

    
    

     

                      {v: months['09_tmean'], f: '9'},
     
    
   

    

     

    
    

     

                      {v: months['10_tmean'], f: 'October'},
     
    
   

    

     

    
    

     

                      {v: months['11_tmean'], f: '11'},
     
    
   

    

     

    
    

     

                      {v: months['12_tmean'], f: '12'},]
     
    
   

    

     

    
    

     

            },
     
    
   

    

     

    
    

     
      vAxis: {
     
    
   

    

     

    
    

     
        title: 'Temperature (Celsius)'
     
    
   

    

     

    
    

     

            },
     
    
   

    

     

    
    

     
      lineWidth: 1,
     
    
   

    

     

    
    

     
      pointSize: 3
     
    
   

    

     

    
    

     

          });
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      print(extremeTempsChart);
     
    
  
 

文章来源: blog.csdn.net，作者：此星光明2021年博客之星云计算Top3，版权归原作者所有，如需转载，请联系作者。

原文链接：blog.csdn.net/qq_31988139/article/details/118976744