X-Git-Url: https://git.auder.net/?p=valse.git;a=blobdiff_plain;f=pkg%2FR%2FEMGLLF.R;h=f944f98e38ca48fcac75c73cd3ac2074551d06e9;hp=5a69a52273da63777dc9fbd3c2966870e00586e6;hb=e32621012b1660204434a56acc8cf73eac42f477;hpb=fb6e49cb85308c3f99cc98fe955aa7c36839c819 diff --git a/pkg/R/EMGLLF.R b/pkg/R/EMGLLF.R deleted file mode 100644 index 5a69a52..0000000 --- a/pkg/R/EMGLLF.R +++ /dev/null @@ -1,192 +0,0 @@ -#' EMGLLF -#' -#' Description de EMGLLF -#' -#' @param phiInit Parametre initial de moyenne renormalisé -#' @param rhoInit Parametre initial de variance renormalisé -#' @param piInit Parametre initial des proportions -#' @param gamInit Paramètre initial des probabilités a posteriori de chaque échantillon -#' @param mini Nombre minimal d'itérations dans l'algorithme EM -#' @param maxi Nombre maximal d'itérations dans l'algorithme EM -#' @param gamma Puissance des proportions dans la pénalisation pour un Lasso adaptatif -#' @param lambda Valeur du paramètre de régularisation du Lasso -#' @param X Régresseurs -#' @param Y Réponse -#' @param tau Seuil pour accepter la convergence -#' -#' @return A list ... phi,rho,pi,LLF,S,affec: -#' phi : parametre de moyenne renormalisé, calculé par l'EM -#' rho : parametre de variance renormalisé, calculé par l'EM -#' pi : parametre des proportions renormalisé, calculé par l'EM -#' LLF : log vraisemblance associée à cet échantillon, pour les valeurs estimées des paramètres -#' S : ... affec : ... -#' -#' @export -EMGLLF <- function(phiInit, rhoInit, piInit, gamInit, - mini, maxi, gamma, lambda, X, Y, tau, fast=TRUE) -{ - if (!fast) - { - # Function in R - return (.EMGLLF_R(phiInit,rhoInit,piInit,gamInit,mini,maxi,gamma,lambda,X,Y,tau)) - } - - # Function in C - n = nrow(X) #nombre d'echantillons - p = ncol(X) #nombre de covariables - m = ncol(Y) #taille de Y (multivarié) - k = length(piInit) #nombre de composantes dans le mélange - .Call("EMGLLF", - phiInit, rhoInit, piInit, gamInit, mini, maxi, gamma, lambda, X, Y, tau, - phi=double(p*m*k), rho=double(m*m*k), pi=double(k), LLF=double(maxi), - S=double(p*m*k), affec=integer(n), - n, p, m, k, - PACKAGE="valse") -} - -# R version - slow but easy to read -.EMGLLF_R = function(phiInit,rhoInit,piInit,gamInit,mini,maxi,gamma,lambda,X2,Y,tau) -{ - # Matrix dimensions - n = dim(Y)[1] - if (length(dim(phiInit)) == 2){ - p = 1 - m = dim(phiInit)[1] - k = dim(phiInit)[2] - } else { - p = dim(phiInit)[1] - m = dim(phiInit)[2] - k = dim(phiInit)[3] - } - X = matrix(nrow = n, ncol = p) - X[1:n,1:p] = X2 - # Outputs - phi = array(NA, dim = c(p,m,k)) - phi[1:p,,] = phiInit - rho = rhoInit - pi = piInit - llh = -Inf - S = array(0, dim=c(p,m,k)) - - # Algorithm variables - gam = gamInit - Gram2 = array(0, dim=c(p,p,k)) - ps2 = array(0, dim=c(p,m,k)) - X2 = array(0, dim=c(n,p,k)) - Y2 = array(0, dim=c(n,m,k)) - EPS = 1e-15 - - for (ite in 1:maxi) - { - # Remember last pi,rho,phi values for exit condition in the end of loop - Phi = phi - Rho = rho - Pi = pi - - # Computations associated to X and Y - for (r in 1:k) - { - for (mm in 1:m) - Y2[,mm,r] = sqrt(gam[,r]) * Y[,mm] - for (i in 1:n) - X2[i,,r] = sqrt(gam[i,r]) * X[i,] - for (mm in 1:m) - ps2[,mm,r] = crossprod(X2[,,r],Y2[,mm,r]) - for (j in 1:p) - { - for (s in 1:p) - Gram2[j,s,r] = crossprod(X2[,j,r], X2[,s,r]) - } - } - - ######### - #M step # - ######### - - # For pi - b = sapply( 1:k, function(r) sum(abs(phi[,,r])) ) - gam2 = colSums(gam) - a = sum(gam %*% log(pi)) - - # While the proportions are nonpositive - kk = 0 - pi2AllPositive = FALSE - while (!pi2AllPositive) - { - pi2 = pi + 0.1^kk * ((1/n)*gam2 - pi) - pi2AllPositive = all(pi2 >= 0) - kk = kk+1 - } - - # t(m) is the largest value in the grid O.1^k such that it is nonincreasing - while( kk < 1000 && -a/n + lambda * sum(pi^gamma * b) < - -sum(gam2 * log(pi2))/n + lambda * sum(pi2^gamma * b) ) - { - pi2 = pi + 0.1^kk * (1/n*gam2 - pi) - kk = kk + 1 - } - t = 0.1^kk - pi = (pi + t*(pi2-pi)) / sum(pi + t*(pi2-pi)) - - #For phi and rho - for (r in 1:k) - { - for (mm in 1:m) - { - ps = 0 - for (i in 1:n) - ps = ps + Y2[i,mm,r] * sum(X2[i,,r] * phi[,mm,r]) - nY2 = sum(Y2[,mm,r]^2) - rho[mm,mm,r] = (ps+sqrt(ps^2+4*nY2*gam2[r])) / (2*nY2) - } - } - - for (r in 1:k) - { - for (j in 1:p) - { - for (mm in 1:m) - { - S[j,mm,r] = -rho[mm,mm,r]*ps2[j,mm,r] + sum(phi[-j,mm,r] * Gram2[j,-j,r]) - if (abs(S[j,mm,r]) <= n*lambda*(pi[r]^gamma)) - phi[j,mm,r]=0 - else if(S[j,mm,r] > n*lambda*(pi[r]^gamma)) - phi[j,mm,r] = (n*lambda*(pi[r]^gamma)-S[j,mm,r]) / Gram2[j,j,r] - else - phi[j,mm,r] = -(n*lambda*(pi[r]^gamma)+S[j,mm,r]) / Gram2[j,j,r] - } - } - } - - ######## - #E step# - ######## - - # Precompute det(rho[,,r]) for r in 1...k - detRho = sapply(1:k, function(r) det(rho[,,r])) - gam1 = matrix(0, nrow = n, ncol = k) - for (i in 1:n) - { - # Update gam[,] - for (r in 1:k) - { - gam1[i,r] = pi[r]*exp(-0.5*sum((Y[i,]%*%rho[,,r]-X[i,]%*%phi[,,r])^2))*detRho[r] - } - } - gam = gam1 / rowSums(gam1) - sumLogLLH = sum(log(rowSums(gam)) - log((2*base::pi)^(m/2))) - sumPen = sum(pi^gamma * b) - last_llh = llh - llh = -sumLogLLH/n + lambda*sumPen - dist = ifelse( ite == 1, llh, (llh-last_llh) / (1+abs(llh)) ) - Dist1 = max( (abs(phi-Phi)) / (1+abs(phi)) ) - Dist2 = max( (abs(rho-Rho)) / (1+abs(rho)) ) - Dist3 = max( (abs(pi-Pi)) / (1+abs(Pi)) ) - dist2 = max(Dist1,Dist2,Dist3) - - if (ite >= mini && (dist >= tau || dist2 >= sqrt(tau))) - break - } - - list( "phi"=phi, "rho"=rho, "pi"=pi, "llh"=llh, "S"=S) -}