[英]Can't access object property in Javascript, property key is from FileReader
[英]javascript - can't access property of an object using its key?
在Google Earth编辑器中,我们使用reduceRegion()函数创建了一个对象:
var meanValue2015 = ndvi2015.reduceRegion({
reducer: ee.Reducer.mean(),
geometry: justEC15.geometry(),
crs: 'EPSG:4326',
scale: 30,
});
我的问题是,meanValue2015似乎是一个对象-我输入
print(meanValue2015);
print(typeof(meanValue2015));
print(Object.keys(meanValue2015));
并分别获得“对象(1属性)-NDVI:0.3177 ...”,“对象”,然后分别是“ []”? 接着
print(meanValue2015.NDVI);
print(meanValue2015['NDVI']);
是不确定的? 我在这里做错什么明显吗?
meanValue2015是Earth Engine对象:Dictionary。 所以..
var meanValue2015 = ndvi2015.reduceRegion({
reducer: ee.Reducer.mean(),
geometry: justEC15.geometry(),
crs: 'EPSG:4326',
scale: 30,
});
var realValue = ee.Number(meanValue2015.get("ndvi"));
print("real value (object):", realValue)
// realValue is a EE object, so you have to use it as is..
// this would be easy, but it is wrong..
var newValueWrong = realValue + 1
// this is the right way..
var newValueRight = realValue.add(ee.Number(1))
print("wrong:", newValueWrong)
print("right:", newValueRight)
// there is another way, but it is not recommendable because you'd
// be wasting EE computing capacity (Google's gift! don't waste it)
var localValue = realValue.getInfo() + 1
print("value in the local scope (try to avoid)", localValue)
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