covariance

名词 n.
中文释义
英 /kəʊˈvɛː.ɹi.əns/    美 /koʊˈvæɹ.i.əns/|/kəʉˈveː.ɹi.əns/

英文释义

名词 n.
  1. A statistical measure defined as scriptstyle operatorname Cov(X,Y)= operatorname E((X-μ)(Y-ν)) given two real-valued random variables X and Y, with expected values scriptstyle E(X),=,μ and scriptstyle E(Y),=,ν. countable,uncountable
    — The elements of such a correlation matrix do not have asymptotic variances and covariances of the form (1.2), even if S has a Wishart distribution.
  2. The conversion of data types from wider to narrower in certain situations. countable,uncountable
    — As we will see in Chapter 8, we see both covariance and contravariance throughout the Java Collections. They largely exist to ensure that the generics just “do the right thing” and behave in a manner that should not surprise the developer.

词形变化

covariances plural

词汇关系

衍生词
autocovariance covariance function covariance mapping covariance matrix crosscovariance eddy covariance isocovariance subcovariance
相关词
covariant

词源

Etymology tree
Proto-Indo-European *ḱe?
Proto-Indo-European *ḱóm
Proto-Italic *kom
Proto-Italic *kom-
Latin con-
Latin co-der.
English co-
English variance
English covariance
From co- + variance.
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