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ui.Chart.image.byRegion
使用集合让一切井井有条
根据您的偏好保存内容并对其进行分类。
根据图片生成图表。提取并绘制图像中一个或多个区域的波段值,每个波段位于单独的序列中。
- X 轴 = 由 xProperty 标记的区域(默认值:'system:index')
- Y 轴 = Reducer 输出。
- Series = 频段名称。
返回图表。
用法 | 返回 |
---|
ui.Chart.image.byRegion(image, regions, reducer, scale, xProperty) | ui.Chart |
参数 | 类型 | 详细信息 |
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image | 图片 | 要从中提取波段值的图片。 |
regions | Feature|FeatureCollection|Geometry|List<Feature>|List<Geometry>,可选 | 要缩减的区域。默认为影像的覆盖区。 |
reducer | Reducer,可选 | 用于生成 y 轴值的 reducer。必须为每个波段返回一个值。默认值为 ee.Reducer.mean()。 |
scale | 数字,可选 | 用于与缩减器搭配使用的缩放比例(以米为单位)。 |
xProperty | 字符串,可选 | 用作 x 轴上每个地区的标签的属性。默认为“system:index”。 |
如未另行说明,那么本页面中的内容已根据知识共享署名 4.0 许可获得了许可,并且代码示例已根据 Apache 2.0 许可获得了许可。有关详情,请参阅 Google 开发者网站政策。Java 是 Oracle 和/或其关联公司的注册商标。
最后更新时间 (UTC):2025-07-25。
[null,null,["最后更新时间 (UTC):2025-07-25。"],[[["\u003cp\u003eGenerates a chart that visualizes band values within specified regions of an image.\u003c/p\u003e\n"],["\u003cp\u003eCharts display band values on the y-axis, region labels on the x-axis, and separate series for each band.\u003c/p\u003e\n"],["\u003cp\u003eUsers can customize the chart by defining regions, specifying a reducer for calculations, setting a scale, and choosing a property for x-axis labels.\u003c/p\u003e\n"],["\u003cp\u003eThe default reducer is \u003ccode\u003eee.Reducer.mean()\u003c/code\u003e, and the default x-axis property is \u003ccode\u003e'system:index'\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eThe function returns a \u003ccode\u003eui.Chart\u003c/code\u003e object.\u003c/p\u003e\n"]]],["The core functionality involves creating a chart from an image by extracting and plotting band values from specified regions. Users define `image`, `regions`, `reducer`, `scale`, and `xProperty`. It extracts band values, uses the provided `reducer` to compute a single y-value per band, which are then plotted as separate series. `regions` are labeled on the x-axis, based on the provided `xProperty`. The chart plots the reduced values per band in different regions, returning a `ui.Chart` object.\n"],null,["# ui.Chart.image.byRegion\n\n\u003cbr /\u003e\n\nGenerates a Chart from an image. Extracts and plots band values in one or more regions in the image, with each band in a separate series.\n\n\u003cbr /\u003e\n\n- X-axis = Region labeled by xProperty (default: 'system:index')\n\n- Y-axis = Reducer output.\n\n- Series = Band name.\n\nReturns a chart.\n\n| Usage | Returns |\n|-----------------------------------------------------------------------------------------|----------|\n| `ui.Chart.image.byRegion(image, `*regions* `, `*reducer* `, `*scale* `, `*xProperty*`)` | ui.Chart |\n\n| Argument | Type | Details |\n|-------------|-----------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------|\n| `image` | Image | Image to extract band values from. |\n| `regions` | Feature\\|FeatureCollection\\|Geometry\\|List\\\u003cFeature\\\u003e\\|List\\\u003cGeometry\\\u003e, optional | Regions to reduce. Defaults to the image's footprint. |\n| `reducer` | Reducer, optional | Reducer that generates the value(s) for the y-axis. Must return a single value per band. Defaults to ee.Reducer.mean(). |\n| `scale` | Number, optional | Scale to use with the reducer in meters. |\n| `xProperty` | String, optional | Property to be used as the label for each Region on the x-axis. Defaults to 'system:index'. |"]]