a covariance matrix (also known as auto-covariance matrix, dispersion matrix, variance matrix, or variance–covariance matrix) is a square matrix giving...
35 KB (5,447 words) - 15:34, 4 November 2024
calculating covariance Analysis of covariance Autocovariance Covariance function Covariance matrix Covariance operator Distance covariance, or Brownian...
29 KB (4,739 words) - 20:20, 24 October 2024
variance-covariance matrix (or simply covariance matrix) showing also the relationship between each pair of variables. This would be a 3×3 matrix when 3...
13 KB (2,206 words) - 10:24, 20 March 2024
probability theory and statistics, a cross-covariance matrix is a matrix whose element in the i, j position is the covariance between the i-th element of a random...
7 KB (1,237 words) - 17:13, 21 April 2024
CMA-ES (redirect from Covariance matrix adaptation)
Covariance matrix adaptation evolution strategy (CMA-ES) is a particular kind of strategy for numerical optimization. Evolution strategies (ES) are stochastic...
46 KB (7,545 words) - 11:27, 22 September 2024
statistics, sometimes the covariance matrix of a multivariate random variable is not known but has to be estimated. Estimation of covariance matrices then deals...
25 KB (3,930 words) - 21:12, 2 August 2024
Principal component analysis (category Matrix decompositions)
of the data's covariance matrix. Thus, the principal components are often computed by eigendecomposition of the data covariance matrix or singular value...
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variable. Then the variances and covariances can be placed in a covariance matrix, in which the (i, j) element is the covariance between the i th random variable...
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{\displaystyle 1\leq j\leq k} . The inverse of the covariance matrix is called the precision matrix, denoted by Q = Σ − 1 {\displaystyle {\boldsymbol {Q}}={\boldsymbol...
65 KB (9,519 words) - 19:47, 3 October 2024
referred to as the residual maker matrix or the annihilator matrix. The covariance matrix of the residuals r {\displaystyle \mathbf {r} } , by error propagation...
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Weighted least squares (redirect from Weight matrix)
generalized least squares, when all the off-diagonal entries of the covariance matrix of the errors, are null. The fit of a model to a data point is measured...
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_{k}} is the covariance matrix of the observation noise, v k {\displaystyle \mathbf {v} _{k}} . Additionally, the cross covariance matrix is also needed...
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(e_{t}e_{t}')=\Omega \,} . The contemporaneous covariance matrix of error terms is a k × k positive-semidefinite matrix denoted Ω. E ( e t e t − k ′ ) = 0 {\displaystyle...
21 KB (3,431 words) - 23:59, 20 October 2024
Complex random variable (redirect from Pseudo-covariance)
( ℜ ( Z ) , ℑ ( Z ) ) {\displaystyle (\Re {(Z)},\Im {(Z)})} has a covariance matrix of the form: [ Var [ ℜ ( Z ) ] Cov [ ℑ ( Z ) , ℜ ( Z ) ] Cov ...
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positive semi-definite square matrix, commonly referred to as the variance-covariance matrix (or simply as the covariance matrix). If X {\displaystyle X} is...
58 KB (10,093 words) - 12:27, 9 November 2024
of random variables with a known covariance matrix into a set of new variables whose covariance is the identity matrix, meaning that they are uncorrelated...
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The covariance matrix (also called second central moment) K Z Z {\displaystyle \operatorname {K} _{\mathbf {Z} \mathbf {Z} }} contains the covariances between...
18 KB (3,034 words) - 01:22, 27 April 2023
steps: a translation, the computation of a covariance matrix, and the computation of the optimal rotation matrix. Both sets of coordinates must be translated...
9 KB (1,139 words) - 09:12, 10 July 2024
respective random variables.: p.333 The covariance matrix (also called second central moment or variance-covariance matrix) of an n × 1 {\displaystyle n\times...
21 KB (3,426 words) - 01:02, 31 July 2024
Autocovariance (redirect from Auto covariance)
a stochastic process, the autocovariance is a function that gives the covariance of the process with itself at pairs of time points. Autocovariance is...
8 KB (1,342 words) - 10:26, 15 May 2024
Kalman filter for large problems (essentially, the covariance matrix is replaced by the sample covariance), and it is now an important data assimilation component...
25 KB (3,897 words) - 21:06, 5 October 2024
Gaussian) a covariance matrix C M {\displaystyle C_{M}} representing the a priori uncertainties on the model parameters, and a covariance matrix C D {\displaystyle...
30 KB (3,941 words) - 18:19, 21 September 2024
the value of x {\displaystyle x} . More generally, if the variance-covariance matrix of disturbance ε i {\displaystyle \varepsilon _{i}} across i {\displaystyle...
27 KB (3,191 words) - 23:32, 30 August 2024
column vector μ {\displaystyle \mu } , and their variances and covariances in a covariance matrix Σ {\displaystyle \Sigma } . Consider a portfolio of risky...
52 KB (7,937 words) - 12:50, 13 October 2024
three parameters: location parameter μ, covariance matrix Γ {\displaystyle \Gamma } , and the relation matrix C {\displaystyle C} . The standard complex...
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Fisher information (redirect from Fisher information matrix)
by Francis Ysidro Edgeworth). The Fisher information matrix is used to calculate the covariance matrices associated with maximum-likelihood estimates...
50 KB (7,558 words) - 04:41, 7 November 2024
uncorrelated if and only if their cross-covariance matrix K X Y {\displaystyle \operatorname {K} _{\mathbf {X} \mathbf {Y} }} matrix is zero. In the case of two complex...
6 KB (889 words) - 21:29, 30 July 2024
covariance matrix of the samples. When the affine span of the samples is not the entire R N {\displaystyle \mathbb {R} ^{N}} , the covariance matrix would...
19 KB (2,683 words) - 22:48, 23 October 2024
Hotelling's T-squared distribution (redirect from Pooled covariance matrix)
{\displaystyle d} is Gaussian multivariate-distributed with zero mean and unit covariance matrix N ( 0 p , I p , p ) {\displaystyle N(\mathbf {0} _{p},\mathbf {I}...
18 KB (1,980 words) - 21:40, 18 September 2024
high-dimensional statistical phenomenon can be found in the problem of covariance matrix estimation. Suppose that we observe X 1 , … , X n ∈ R p {\displaystyle...
20 KB (2,559 words) - 15:42, 4 October 2024