variance

noun

1. an activity that varies from a norm or standard

e.g. any variation in his routine was immediately reported

Synonym: variation

2. an official dispensation to act contrary to a rule or regulation (typically a building regulation)

e.g. a zoning variance

3. the quality of being subject to variation

Synonym: variabilityvariableness

4. a difference between conflicting facts or claims or opinions

e.g. a growing divergence of opinion

Synonym: discrepancydisagreementdivergence

5. the second moment around the mean
the expected value of the square of the deviations of a random variable from its mean value

6. discord that splits a group

Synonym: division

7. an event that departs from expectations

Synonym: discrepancyvariant

1. （与…）不一致，相矛盾
If one thing is at variance with another, the two things seem to contradict each other.

e.g. Many of his statements were at variance with the facts...
他的说法有很多和事实不符。
e.g. This idealistic concept is at variance with reality.
这种理想主义的观念和现实相矛盾。

2. 差异;不同
The variance between things is the difference between them.

e.g. ...the variances in the stock price.
股票价格的变化
e.g. ...total revenue variance.
总收入的差异

1. 方差：16 方差(variance)是一组数据中各变量与其均值离差平方的平均数,方差的算术平方根叫标准差(standard deviation). 方差与标准差是反映数值型数据离散程度的主要的也是常用的方法,是描述数据分布特征的重要的统计量.

2. 变异数：心率变异性分析则是通过测量连续正常的QRS波群周期之间的变化(beat to fluctuation)变异数(Variance),从而反应心率的变化. 它不同于常用的以时间为单位的平均心率变化指标(如最大心率或最小心率等),HRV的大小并不反映心率的快慢.

3. 差异：除此之外,Breiman [Bre96a] 还从偏向(bias)和差异(variance)的角度对泛化误差进行了分析. 他指出,不稳定预测函数的偏向较小、差异较大,Bagging正是通过减小差异来减小泛化误差的. 在此之后,