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Table 1 Formulas for computing partial variances and partial correlations

From: From correlation to causation networks: a simple approximate learning algorithm and its application to high-dimensional plant gene expression data

 

Definition

True value

Estimate

Covariance matrix:

cov(X k , X l ) = σ kl

Σ = (σ kl )

S= (s kl )

Concentration matrix:

Ω = Σ-1

Ω = (ω kl )

 

Variances:

var(X k ) = σ kk = σ k 2 MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaaiiGacqWFdpWCdaqhaaWcbaGaem4AaSgabaGaeGOmaidaaaaa@30F4@

σ kk

s kk

Partial variances

var(X k |Xk) = σ ˜ k k MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaaiiGacuWFdpWCgaacamaaBaaaleaacqWGRbWAcqWGRbWAaeqaaaaa@316F@ = σ ˜ k 2 MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaaiiGacuWFdpWCgaacamaaDaaaleaacqWGRbWAaeaacqaIYaGmaaaaaa@3103@ = ω k k 1 MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaaiiGacqWFjpWDdaqhaaWcbaGaem4AaSMaem4AaSgabaGaeyOeI0IaeGymaedaaaaa@3348@

σ ˜ k k MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaaiiGacuWFdpWCgaacamaaBaaaleaacqWGRbWAcqWGRbWAaeqaaaaa@316F@

s ˜ k k MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaacuWGZbWCgaacamaaBaaaleaacqWGRbWAcqWGRbWAaeqaaaaa@3114@

Correlations:

corr(X k , X l ) = ρ kl = σ kl (σ kk σ ll )-1/2

P= (ρ kl )

R= (r kl )

Partial correlations:

corr(X k , X l |Xk, l) = ρ ˜ k l = ω k l ( ω k k ω l l ) 1 / 2 MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaaiiGacuWFbpGCgaacamaaBaaaleaacqWGRbWAcqWGSbaBaeqaaOGaeyypa0JaeyOeI0Iae8xYdC3aaSbaaSqaaiabdUgaRjabdYgaSbqabaGccqGGOaakcqWFjpWDdaWgaaWcbaGaem4AaSMaem4AaSgabeaakiab=L8a3naaBaaaleaacqWGSbaBcqWGSbaBaeqaaOGaeiykaKYaaWbaaSqabeaacqGHsislcqaIXaqmcqGGVaWlcqaIYaGmaaaaaa@4739@

P ˜ = ( ρ ˜ k l ) MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaaieWacuWFqbaugaacaiabg2da9maabmaabaacciGaf4xWdiNbaGaadaWgaaWcbaGaem4AaSMaemiBaWgabeaaaOGaayjkaiaawMcaaaaa@3546@

R ˜ = ( r ˜ k l ) MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaaieWacuWFsbGugaacaiabg2da9maabmaabaGafmOCaiNbaGaadaWgaaWcbaGaem4AaSMaemiBaWgabeaaaOGaayjkaiaawMcaaaaa@34F1@

  1. Index i runs from 1 to n (sample size), and indices k and l run from 1 to p (dimension). A tilde denotes a "partial" quantity.