Pseudo regression coefficients from generalized partial correlation coefficients, (GPCC).
Pseudo regression coefficients from generalized partial correlation coefficients, (GPCC).
This function gets the GPCCs by calling the parcorVec function. The pseudo regression coefficient of a kernel regression is then obtained by [GPCC*(sd dep.var)/(sd regressor)], that is, by multiplying the GPCC by the standard deviation (sd) of the dependent variable, and dividing by the sd of the regressor.
sudoCoefParcor(mtx, ctrl =0, verbo =FALSE, idep =1)
Arguments
mtx: Input data matrix with p (> or = 3) columns,
ctrl: Input vector or matrix of data for control variable(s), default is ctrl=0, when control variables are absent
verbo: Make this TRUE for detailed printing of computational steps
idep: The column number of the dependent variable (=1, default)
Returns
A p by 1 `out' vector pseudo partial derivatives.
Note
Generalized Partial Correlation Coefficients (GPCC) allow comparison of the relative contribution of each Xj to the explanation of Xi, because GPCC are scale-free. The pseudo regression coefficient are not scale-free since they equal GPCC*(sd dep.var)/(sd regressor)
We want to get all partial correlation coefficient pairs removing other column effects. Vinod (2018) shows why one needs more than one criterion to decide the causal paths or exogeneity.
Examples
set.seed(234)z=runif(10,2,11)# z is independently createdx=sample(1:10)+z/10#x is partly indep and partly affected by zy=1+2*x+3*z+rnorm(10)# y depends on x and z not vice versamtx=cbind(x,y,z)sudoCoefParcor(mtx, idep=2)## Not run:set.seed(34);x=matrix(sample(1:600)[1:99],ncol=3)colnames(x)=c('V1','v2','V3')#some names neededsudoCoefParcor(x)## End(Not run)
Vinod, H. D. 'Matrix Algebra Topics in Statistics and Economics Using R', Chapter 4 in Handbook of Statistics: Computational Statistics with R, Vol.32, co-editors: M. B. Rao and C.R. Rao. New York: North Holland, Elsevier Science Publishers, 2014, pp. 143-176.