• Thumbnail for Covariance matrix
    a covariance matrix (also known as auto-covariance matrix, dispersion matrix, variance matrix, or variance–covariance matrix) is a square matrix giving...
    34 KB (5,418 words) - 23:44, 30 May 2024
  • calculating covariance Analysis of covariance Autocovariance Covariance function Covariance matrix Covariance operator Distance covariance, or Brownian...
    29 KB (4,693 words) - 08:43, 18 June 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
  • 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) - 07:52, 22 June 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) - 22:37, 24 June 2024
  • 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...
    4 KB (638 words) - 20:58, 15 March 2023
  • Thumbnail for Principal component analysis
    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...
    114 KB (14,283 words) - 16:49, 3 July 2024
  • (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 (3,495 words) - 07:55, 28 May 2024
  • Thumbnail for Kalman filter
    _{k}} is the covariance matrix of the observation noise, v k {\displaystyle \mathbf {v} _{k}} . Additionally, the cross covariance matrix is also needed...
    129 KB (20,535 words) - 05:27, 1 July 2024
  • 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...
    14 KB (2,249 words) - 06:44, 14 June 2024
  • Thumbnail for Complex random vector
    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
  • Thumbnail for Multivariate normal distribution
    {\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...
    64 KB (9,444 words) - 15:36, 3 July 2024
  • Thumbnail for Complex random variable
    ( 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 ⁡...
    16 KB (2,276 words) - 03:38, 16 November 2023
  • referred to as the residual maker matrix or the annihilator matrix. The covariance matrix of the residuals r {\displaystyle \mathbf {r} } , by error propagation...
    13 KB (1,837 words) - 14:54, 22 May 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...
    7 KB (802 words) - 01:33, 4 January 2024
  • Thumbnail for Variance
    positive semi-definite square matrix, commonly referred to as the variance-covariance matrix (or simply as the covariance matrix). If X {\displaystyle X} is...
    57 KB (10,018 words) - 20:40, 27 June 2024
  • 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
  • Thumbnail for Homoscedasticity and heteroscedasticity
    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) - 15:51, 29 May 2024
  • 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 (1,147 words) - 07:12, 19 June 2024
  • Thumbnail for Multivariate random variable
    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 (3,433 words) - 09:35, 25 March 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 (2,560 words) - 23:59, 6 January 2024
  • three parameters: location parameter μ, covariance matrix Γ {\displaystyle \Gamma } , and the relation matrix C {\displaystyle C} . The standard complex...
    16 KB (2,288 words) - 00:08, 11 May 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 (2,684 words) - 09:30, 23 June 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) - 07:05, 27 April 2022
  • Thumbnail for Hotelling's T-squared distribution
    {\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}...
    17 KB (1,921 words) - 23:42, 24 June 2024
  • theory and statistics, the covariance function describes how much two random variables change together (their covariance) with varying spatial or temporal...
    4 KB (582 words) - 18:22, 13 June 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 (7,890 words) - 06:07, 17 June 2024
  • }K\mathbf {g} >0\ ,} implying that the conductivity matrix should be positive definite. Covariance matrix M-matrix Positive-definite function Positive-definite...
    50 KB (8,509 words) - 10:50, 9 June 2024
  • Thumbnail for Simple linear regression
    \end{aligned}}} The solution can be reformulated using elements of the covariance matrix: β ^ = s x , y s x 2 = r x y s y s x {\displaystyle {\widehat {\beta...
    29 KB (4,722 words) - 15:12, 23 May 2024