Results 11 to 20 of about 615,565 (289)

pyGNMF: A Python library for implementation of generalised non-negative matrix factorisation method

open access: yesSoftwareX, 2022
This article introduces a Python library named pyGNMF, which implements the recently proposed generalised non-negative matrix factorisation (GNMF) method.
Nirav L. Lekinwala, Mani Bhushan
doaj   +1 more source

Weighted covariance matrix estimation [PDF]

open access: yesComputational Statistics & Data Analysis, 2019
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Guangren Yang, Yiming Liu, Guangming Pan
openaire   +3 more sources

The effect on cosmological parameter estimation of a parameter dependent covariance matrix

open access: yesThe Open Journal of Astrophysics, 2019
Cosmological large-scale structure analyses based on two-point correlation functions often assume a Gaussian likelihood function with a fixed covariance matrix. We study the impact on cosmological parameter estimation of ignoring the parameter dependence
Darsh Kodwani   +2 more
doaj   +2 more sources

Sparse estimation of a covariance matrix [PDF]

open access: yesBiometrika, 2011
We suggest a method for estimating a covariance matrix on the basis of a sample of vectors drawn from a multivariate normal distribution. In particular, we penalize the likelihood with a lasso penalty on the entries of the covariance matrix. This penalty plays two important roles: it reduces the effective number of parameters, which is important even ...
Jacob Bien, Robert J. Tibshirani
openaire   +3 more sources

A cautionary note on robust covariance plug-in methods [PDF]

open access: yes, 2014
Many multivariate statistical methods rely heavily on the sample covariance matrix. It is well known though that the sample covariance matrix is highly non-robust.
Nordhausen, Klaus, Tyler, David E.
core   +1 more source

The Intraclass Covariance Matrix [PDF]

open access: yesBehavior Genetics, 2005
Introduced by C.R. Rao in 1945, the intraclass covariance matrix has seen little use in behavioral genetic research, despite the fact that it was developed to deal with family data. Here, I reintroduce this matrix, and outline its estimation and basic properties for data sets on pairs of relatives.
openaire   +2 more sources

Impact of different estimations of the background-error covariance matrix on climate reconstructions based on data assimilation [PDF]

open access: yesClimate of the Past, 2019
Data assimilation has been adapted in paleoclimatology to reconstruct past climate states. A key component of some assimilation systems is the background-error covariance matrix, which controls how the information from observations spreads into the model
V. Valler   +5 more
doaj   +1 more source

Remarks on covariant matrix strings [PDF]

open access: yesPhysics Letters B, 1999
15 pages, harvmac.
Baulieu, Laurent   +2 more
openaire   +2 more sources

A Kernel Gabor-Based Weighted Region Covariance Matrix for Face Recognition

open access: yesSensors, 2012
This paper proposes a novel image region descriptor for face recognition, named kernel Gabor-based weighted region covariance matrix (KGWRCM). As different parts are different effectual in characterizing and recognizing faces, we construct a weighting ...
Yantao Li   +3 more
doaj   +1 more source

Discriminant methods for high dimensional data [PDF]

open access: yesSongklanakarin Journal of Science and Technology (SJST), 2019
The main purpose of discriminant analysis is to enable classification of new observations into one of g classes or populations. Discriminant methods suffer when applied to high dimensional data because the sample covariance matrix is singular.
Poompong Kaewumpai, Samruam Chongcharoen
doaj   +1 more source

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