公告：凡是在
2025 年 4 月 15 日前註冊使用 Earth Engine 的非商業專案，都必須
驗證非商業用途資格，才能繼續存取 Earth Engine。
ee.Reducer.covariance
透過集合功能整理內容
你可以依據偏好儲存及分類內容。
建立縮減器，將相同長度 N 的 1 維陣列縮減為 NxN 形狀的共變異數矩陣。這個縮減器會使用 Sandia 國家實驗室技術報告 SAND2008-6212 中的單次傳遞共變異數公式，如果值涵蓋的範圍很廣，準確度可能會降低。
| 用量 | 傳回 |
|---|
ee.Reducer.covariance() | 縮減函式 |
沒有引數。
除非另有註明，否則本頁面中的內容是採用創用 CC 姓名標示 4.0 授權，程式碼範例則為阿帕契 2.0 授權。詳情請參閱《Google Developers 網站政策》。Java 是 Oracle 和/或其關聯企業的註冊商標。
上次更新時間：2025-07-26 (世界標準時間)。
[null,null,["上次更新時間：2025-07-26 (世界標準時間)。"],[[["\u003cp\u003eCreates a reducer for calculating the covariance matrix from multiple 1-D arrays.\u003c/p\u003e\n"],["\u003cp\u003eUtilizes a one-pass covariance formula which may be less accurate with large value ranges.\u003c/p\u003e\n"],["\u003cp\u003eOutput is an NxN covariance matrix where N is the length of the input arrays.\u003c/p\u003e\n"],["\u003cp\u003eThe reducer is created using \u003ccode\u003eee.Reducer.covariance()\u003c/code\u003e.\u003c/p\u003e\n"]]],["This describes a reducer function that computes a covariance matrix from multiple 1-D arrays of identical length. The output is an NxN covariance matrix. It employs a one-pass covariance formula, as detailed in Sandia National Laboratories Technical Report SAND2008-6212. The key action is reducing multiple arrays into a single matrix, and the critical information is the use of a specific formula which can result in decreased accuracy if the input data contains a broad range of values.\n"],null,["# ee.Reducer.covariance\n\nCreates a reducer that reduces some number of 1-D arrays of the same length N to a covariance matrix of shape NxN. This reducer uses the one-pass covariance formula from Sandia National Laboratories Technical Report SAND2008-6212, which can lose accuracy if the values span a large range.\n\n\u003cbr /\u003e\n\n\u003cbr /\u003e\n\n| Usage | Returns |\n|---------------------------|---------|\n| `ee.Reducer.covariance()` | Reducer |\n\n**No arguments.**"]]
