prepare structure for R package
[valse.git] / src / sources / EMGLLF.c
diff --git a/src/sources/EMGLLF.c b/src/sources/EMGLLF.c
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+#include "EMGLLF.h"
+#include <gsl/gsl_linalg.h>
+
+// TODO: comment on EMGLLF purpose
+void EMGLLF(
+       // IN parameters
+       const Real* phiInit,  // parametre initial de moyenne renormalisé
+       const Real* rhoInit,  // parametre initial de variance renormalisé
+       const Real* piInit,   // parametre initial des proportions
+       const Real* gamInit,  // paramètre initial des probabilités a posteriori de chaque échantillon
+       Int mini,      // nombre minimal d'itérations dans l'algorithme EM     
+       Int maxi,      // nombre maximal d'itérations dans l'algorithme EM
+       Real gamma,  // valeur de gamma : puissance des proportions dans la pénalisation pour un Lasso adaptatif
+       Real lambda, // valeur du paramètre de régularisation du Lasso
+       const Real* X,     // régresseurs
+       const Real* Y,     // réponse
+       Real tau,    // seuil pour accepter la convergence
+       // OUT parameters (all pointers, to be modified)
+       Real* phi,  // parametre de moyenne renormalisé, calculé par l'EM
+       Real* rho,  // parametre de variance renormalisé, calculé par l'EM
+       Real* pi,   // parametre des proportions renormalisé, calculé par l'EM
+       Real* LLF,   // log vraisemblance associé à cet échantillon, pour les valeurs estimées des paramètres
+    Real* S,
+       // additional size parameters
+       mwSize n,         // nombre d'echantillons
+       mwSize p,         // nombre de covariables
+       mwSize m,         // taille de Y (multivarié)
+       mwSize k)         // nombre de composantes dans le mélange
+{
+       //Initialize outputs
+       copyArray(phiInit, phi, p*m*k);
+       copyArray(rhoInit, rho, m*m*k);
+       copyArray(piInit, pi, k);
+       zeroArray(LLF, maxi);
+       //S is already allocated, and doesn't need to be 'zeroed'
+       
+       //Other local variables
+       //NOTE: variables order is always [maxi],n,p,m,k
+       Real* gam = (Real*)malloc(n*k*sizeof(Real));
+       copyArray(gamInit, gam, n*k);
+       Real* b = (Real*)malloc(k*sizeof(Real));
+       Real* Phi = (Real*)malloc(p*m*k*sizeof(Real));
+       Real* Rho = (Real*)malloc(m*m*k*sizeof(Real));
+       Real* Pi = (Real*)malloc(k*sizeof(Real));
+       Real* gam2 = (Real*)malloc(k*sizeof(Real));
+       Real* pi2 = (Real*)malloc(k*sizeof(Real));
+       Real* Gram2 = (Real*)malloc(p*p*k*sizeof(Real));
+       Real* ps = (Real*)malloc(m*k*sizeof(Real));
+       Real* nY2 = (Real*)malloc(m*k*sizeof(Real));
+       Real* ps1 = (Real*)malloc(n*m*k*sizeof(Real));
+       Real* ps2 = (Real*)malloc(p*m*k*sizeof(Real));
+       Real* nY21 = (Real*)malloc(n*m*k*sizeof(Real));
+       Real* Gam = (Real*)malloc(n*k*sizeof(Real));
+       Real* X2 = (Real*)malloc(n*p*k*sizeof(Real));
+       Real* Y2 = (Real*)malloc(n*m*k*sizeof(Real));
+       gsl_matrix* matrix = gsl_matrix_alloc(m, m);
+       gsl_permutation* permutation = gsl_permutation_alloc(m);
+       Real* YiRhoR = (Real*)malloc(m*sizeof(Real));
+       Real* XiPhiR = (Real*)malloc(m*sizeof(Real));
+       Real dist = 0.0;
+       Real dist2 = 0.0;
+       Int ite = 0;
+       Real EPS = 1e-15;
+       Real* dotProducts = (Real*)malloc(k*sizeof(Real));
+       
+       while (ite < mini || (ite < maxi && (dist >= tau || dist2 >= sqrt(tau))))
+       {
+               copyArray(phi, Phi, p*m*k);
+               copyArray(rho, Rho, m*m*k);
+               copyArray(pi, Pi, k);
+               
+               // Calculs associes a Y et X
+               for (mwSize r=0; r<k; r++)
+               {
+                       for (mwSize mm=0; mm<m; mm++)
+                       {
+                               //Y2(:,mm,r)=sqrt(gam(:,r)).*transpose(Y(mm,:));
+                               for (mwSize u=0; u<n; u++)
+                                       Y2[u*m*k+mm*k+r] = sqrt(gam[u*k+r]) * Y[u*m+mm];
+                       }
+                       for (mwSize i=0; i<n; i++)
+                       {
+                               //X2(i,:,r)=X(i,:).*sqrt(gam(i,r));
+                               for (mwSize u=0; u<p; u++)
+                                       X2[i*p*k+u*k+r] = sqrt(gam[i*k+r]) * X[i*p+u];
+                       }
+                       for (mwSize mm=0; mm<m; mm++)
+                       {
+                               //ps2(:,mm,r)=transpose(X2(:,:,r))*Y2(:,mm,r);
+                               for (mwSize u=0; u<p; u++)
+                               {
+                                       Real dotProduct = 0.0;
+                                       for (mwSize v=0; v<n; v++)
+                                               dotProduct += X2[v*p*k+u*k+r] * Y2[v*m*k+mm*k+r];
+                                       ps2[u*m*k+mm*k+r] = dotProduct;
+                               }
+                       }
+                       for (mwSize j=0; j<p; j++)
+                       {
+                               for (mwSize s=0; s<p; s++)
+                               {
+                                       //Gram2(j,s,r)=transpose(X2(:,j,r))*(X2(:,s,r));
+                                       Real dotProduct = 0.0;
+                                       for (mwSize u=0; u<n; u++)
+                                               dotProduct += X2[u*p*k+j*k+r] * X2[u*p*k+s*k+r];                                        
+                                       Gram2[j*p*k+s*k+r] = dotProduct;
+                               }
+                       }
+               }
+
+               /////////////
+               // Etape M //
+               /////////////
+               
+               // Pour pi
+               for (mwSize r=0; r<k; r++)
+               {
+                       //b(r) = sum(sum(abs(phi(:,:,r))));
+                       Real sumAbsPhi = 0.0;
+                       for (mwSize u=0; u<p; u++)
+                               for (mwSize v=0; v<m; v++)
+                                       sumAbsPhi += fabs(phi[u*m*k+v*k+r]);
+                       b[r] = sumAbsPhi;
+               }
+               //gam2 = sum(gam,1);
+               for (mwSize u=0; u<k; u++)
+               {
+                       Real sumOnColumn = 0.0;
+                       for (mwSize v=0; v<n; v++)
+                               sumOnColumn += gam[v*k+u];
+                       gam2[u] = sumOnColumn;
+               }
+               //a=sum(gam*transpose(log(pi)));
+               Real a = 0.0;
+               for (mwSize u=0; u<n; u++)
+               {
+                       Real dotProduct = 0.0;
+                       for (mwSize v=0; v<k; v++)
+                               dotProduct += gam[u*k+v] * log(pi[v]);
+                       a += dotProduct;
+               }
+               
+               //tant que les proportions sont negatives
+               mwSize kk = 0;
+               int pi2AllPositive = 0;
+               Real invN = 1.0/n;
+               while (!pi2AllPositive)
+               {
+                       //pi2(:)=pi(:)+0.1^kk*(1/n*gam2(:)-pi(:));
+                       for (mwSize r=0; r<k; r++)
+                               pi2[r] = pi[r] + pow(0.1,kk) * (invN*gam2[r] - pi[r]);
+                       pi2AllPositive = 1;
+                       for (mwSize r=0; r<k; r++)
+                       {
+                               if (pi2[r] < 0)
+                               {
+                                       pi2AllPositive = 0;
+                                       break;
+                               }
+                       }
+                       kk++;
+               }
+               
+               //t(m) la plus grande valeur dans la grille O.1^k tel que ce soit décroissante ou constante
+               //(pi.^gamma)*b
+               Real piPowGammaDotB = 0.0;
+               for (mwSize v=0; v<k; v++)
+                       piPowGammaDotB += pow(pi[v],gamma) * b[v];
+               //(pi2.^gamma)*b
+               Real pi2PowGammaDotB = 0.0;
+               for (mwSize v=0; v<k; v++)
+                       pi2PowGammaDotB += pow(pi2[v],gamma) * b[v];
+               //transpose(gam2)*log(pi2)
+               Real prodGam2logPi2 = 0.0;
+               for (mwSize v=0; v<k; v++)
+                       prodGam2logPi2 += gam2[v] * log(pi2[v]);
+               while (-invN*a + lambda*piPowGammaDotB < -invN*prodGam2logPi2 + lambda*pi2PowGammaDotB && kk<1000)
+               {
+                       //pi2=pi+0.1^kk*(1/n*gam2-pi);
+                       for (mwSize v=0; v<k; v++)
+                               pi2[v] = pi[v] + pow(0.1,kk) * (invN*gam2[v] - pi[v]);
+                       //pi2 was updated, so we recompute pi2PowGammaDotB and prodGam2logPi2
+                       pi2PowGammaDotB = 0.0;
+                       for (mwSize v=0; v<k; v++)
+                               pi2PowGammaDotB += pow(pi2[v],gamma) * b[v];
+                       prodGam2logPi2 = 0.0;
+                       for (mwSize v=0; v<k; v++)
+                               prodGam2logPi2 += gam2[v] * log(pi2[v]);
+                       kk++;
+               }
+               Real t = pow(0.1,kk);
+               //sum(pi+t*(pi2-pi))
+               Real sumPiPlusTbyDiff = 0.0;
+               for (mwSize v=0; v<k; v++)
+                       sumPiPlusTbyDiff += (pi[v] + t*(pi2[v] - pi[v]));
+               //pi=(pi+t*(pi2-pi))/sum(pi+t*(pi2-pi));
+               for (mwSize v=0; v<k; v++)
+                       pi[v] = (pi[v] + t*(pi2[v] - pi[v])) / sumPiPlusTbyDiff;
+               
+               //Pour phi et rho
+               for (mwSize r=0; r<k; r++)
+               {
+                       for (mwSize mm=0; mm<m; mm++)
+                       {
+                               for (mwSize i=0; i<n; i++)
+                               {
+                                       //< X2(i,:,r) , phi(:,mm,r) >
+                                       Real dotProduct = 0.0;
+                                       for (mwSize u=0; u<p; u++)
+                                               dotProduct += X2[i*p*k+u*k+r] * phi[u*m*k+mm*k+r];
+                                       //ps1(i,mm,r)=Y2(i,mm,r)*dot(X2(i,:,r),phi(:,mm,r));
+                                       ps1[i*m*k+mm*k+r] = Y2[i*m*k+mm*k+r] * dotProduct;
+                                       nY21[i*m*k+mm*k+r] = Y2[i*m*k+mm*k+r] * Y2[i*m*k+mm*k+r];
+                               }
+                               //ps(mm,r)=sum(ps1(:,mm,r));
+                               Real sumPs1 = 0.0;
+                               for (mwSize u=0; u<n; u++)
+                                       sumPs1 += ps1[u*m*k+mm*k+r];
+                               ps[mm*k+r] = sumPs1;
+                               //nY2(mm,r)=sum(nY21(:,mm,r));
+                               Real sumNy21 = 0.0;
+                               for (mwSize u=0; u<n; u++)
+                                       sumNy21 += nY21[u*m*k+mm*k+r];
+                               nY2[mm*k+r] = sumNy21;
+                               //rho(mm,mm,r)=((ps(mm,r)+sqrt(ps(mm,r)^2+4*nY2(mm,r)*(gam2(r))))/(2*nY2(mm,r)));
+                               rho[mm*m*k+mm*k+r] = ( ps[mm*k+r] + sqrt( ps[mm*k+r]*ps[mm*k+r] 
+                                       + 4*nY2[mm*k+r] * (gam2[r]) ) ) / (2*nY2[mm*k+r]);
+                       }
+               }
+               for (mwSize r=0; r<k; r++)
+               {
+                       for (mwSize j=0; j<p; j++)
+                       {
+                               for (mwSize mm=0; mm<m; mm++)
+                               {
+                                       //sum(phi(1:j-1,mm,r).*transpose(Gram2(j,1:j-1,r)))+sum(phi(j+1:p,mm,r).*transpose(Gram2(j,j+1:p,r)))
+                                       Real dotPhiGram2 = 0.0;
+                                       for (mwSize u=0; u<j; u++)
+                                               dotPhiGram2 += phi[u*m*k+mm*k+r] * Gram2[j*p*k+u*k+r];
+                                       for (mwSize u=j+1; u<p; u++)
+                                               dotPhiGram2 += phi[u*m*k+mm*k+r] * Gram2[j*p*k+u*k+r];
+                                       //S(j,r,mm)=-rho(mm,mm,r)*ps2(j,mm,r)+sum(phi(1:j-1,mm,r).*transpose(Gram2(j,1:j-1,r)))
+                                       //    +sum(phi(j+1:p,mm,r).*transpose(Gram2(j,j+1:p,r)));
+                                       S[j*m*k+mm*k+r] = -rho[mm*m*k+mm*k+r] * ps2[j*m*k+mm*k+r] + dotPhiGram2;
+                                       if (fabs(S[j*m*k+mm*k+r]) <= n*lambda*pow(pi[r],gamma))
+                                               phi[j*m*k+mm*k+r] = 0;
+                                       else if (S[j*m*k+mm*k+r] > n*lambda*pow(pi[r],gamma))
+                                               phi[j*m*k+mm*k+r] = (n*lambda*pow(pi[r],gamma) - S[j*m*k+mm*k+r]) 
+                                                       / Gram2[j*p*k+j*k+r];
+                                       else
+                                               phi[j*m*k+mm*k+r] = -(n*lambda*pow(pi[r],gamma) + S[j*m*k+mm*k+r]) 
+                                                       / Gram2[j*p*k+j*k+r];
+                               }
+                       }
+               }
+               
+               /////////////
+               // Etape E //
+               /////////////
+               
+               int signum;
+               Real sumLogLLF2 = 0.0;
+               for (mwSize i=0; i<n; i++)
+               {
+                       Real sumLLF1 = 0.0;
+                       Real sumGamI = 0.0;
+                       Real minDotProduct = INFINITY;
+            
+                       for (mwSize r=0; r<k; r++)
+                       {
+                               //Compute
+                               //Gam(i,r) = Pi(r) * det(Rho(:,:,r)) * exp( -1/2 * (Y(i,:)*Rho(:,:,r) - X(i,:)...
+                               //    *phi(:,:,r)) * transpose( Y(i,:)*Rho(:,:,r) - X(i,:)*phi(:,:,r) ) );
+                               //split in several sub-steps
+                               
+                               //compute Y(i,:)*rho(:,:,r)
+                               for (mwSize u=0; u<m; u++)
+                               {
+                                       YiRhoR[u] = 0.0;
+                                       for (mwSize v=0; v<m; v++)
+                                               YiRhoR[u] += Y[i*m+v] * rho[v*m*k+u*k+r];
+                               }
+                               
+                               //compute X(i,:)*phi(:,:,r)
+                               for (mwSize u=0; u<m; u++)
+                               {
+                                       XiPhiR[u] = 0.0;
+                                       for (mwSize v=0; v<p; v++)
+                                               XiPhiR[u] += X[i*p+v] * phi[v*m*k+u*k+r];
+                               }
+                               
+                               // compute dotProduct < Y(:,i)*rho(:,:,r)-X(i,:)*phi(:,:,r) . Y(:,i)*rho(:,:,r)-X(i,:)*phi(:,:,r) >
+                               dotProducts[r] = 0.0;
+                               for (mwSize u=0; u<m; u++)
+                                       dotProducts[r] += (YiRhoR[u]-XiPhiR[u]) * (YiRhoR[u]-XiPhiR[u]);
+                               if (dotProducts[r] < minDotProduct)
+                                       minDotProduct = dotProducts[r];
+                       }
+                       Real shift = 0.5*minDotProduct;
+                       for (mwSize r=0; r<k; r++)
+                       {
+                               //compute det(rho(:,:,r)) [TODO: avoid re-computations]
+                               for (mwSize u=0; u<m; u++)
+                               {
+                                       for (mwSize v=0; v<m; v++)
+                                               matrix->data[u*m+v] = rho[u*m*k+v*k+r];
+                               }
+                               gsl_linalg_LU_decomp(matrix, permutation, &signum);
+                               Real detRhoR = gsl_linalg_LU_det(matrix, signum);
+                               
+                               Gam[i*k+r] = pi[r] * detRhoR * exp(-0.5*dotProducts[r] + shift);
+                               sumLLF1 += Gam[i*k+r] / pow(2*M_PI,m/2.0);
+                               sumGamI += Gam[i*k+r];
+                       }
+                       sumLogLLF2 += log(sumLLF1);
+                       for (mwSize r=0; r<k; r++)
+                       {
+                               //gam(i,r)=Gam(i,r)/sum(Gam(i,:));
+                               gam[i*k+r] = sumGamI > EPS
+                                       ? Gam[i*k+r] / sumGamI
+                                       : 0.0;
+                       }
+               }
+               
+               //sum(pen(ite,:))
+               Real sumPen = 0.0;
+               for (mwSize r=0; r<k; r++)
+                       sumPen += pow(pi[r],gamma) * b[r];
+               //LLF(ite)=-1/n*sum(log(LLF2(ite,:)))+lambda*sum(pen(ite,:));
+               LLF[ite] = -invN * sumLogLLF2 + lambda * sumPen;
+               if (ite == 0)
+                       dist = LLF[ite];
+               else 
+                       dist = (LLF[ite] - LLF[ite-1]) / (1.0 + fabs(LLF[ite]));
+               
+               //Dist1=max(max((abs(phi-Phi))./(1+abs(phi))));
+               Real Dist1 = 0.0;
+               for (mwSize u=0; u<p; u++)
+               {
+                       for (mwSize v=0; v<m; v++)
+                       {
+                               for (mwSize w=0; w<k; w++)
+                               {
+                                       Real tmpDist = fabs(phi[u*m*k+v*k+w]-Phi[u*m*k+v*k+w]) 
+                                               / (1.0+fabs(phi[u*m*k+v*k+w]));
+                                       if (tmpDist > Dist1)
+                                               Dist1 = tmpDist;
+                               }
+                       }
+               }
+               //Dist2=max(max((abs(rho-Rho))./(1+abs(rho))));
+               Real Dist2 = 0.0;
+               for (mwSize u=0; u<m; u++)
+               {
+                       for (mwSize v=0; v<m; v++)
+                       {
+                               for (mwSize w=0; w<k; w++)
+                               {
+                                       Real tmpDist = fabs(rho[u*m*k+v*k+w]-Rho[u*m*k+v*k+w]) 
+                                               / (1.0+fabs(rho[u*m*k+v*k+w]));
+                                       if (tmpDist > Dist2)
+                                               Dist2 = tmpDist;
+                               }
+                       }
+               }
+               //Dist3=max(max((abs(pi-Pi))./(1+abs(Pi))));
+               Real Dist3 = 0.0;
+               for (mwSize u=0; u<n; u++)
+               {
+                       for (mwSize v=0; v<k; v++)
+                       {
+                               Real tmpDist = fabs(pi[v]-Pi[v]) / (1.0+fabs(pi[v]));
+                               if (tmpDist > Dist3)
+                                       Dist3 = tmpDist;
+                       }
+               }
+               //dist2=max([max(Dist1),max(Dist2),max(Dist3)]);
+               dist2 = Dist1;
+               if (Dist2 > dist2)
+                       dist2 = Dist2;
+               if (Dist3 > dist2)
+                       dist2 = Dist3;
+               
+               ite++;
+       }
+       
+       //free memory
+       free(b);
+       free(gam);
+       free(Gam);
+       free(Phi);
+       free(Rho);
+       free(Pi);
+       free(ps);
+       free(nY2);
+       free(ps1);
+       free(nY21);
+       free(Gram2);
+       free(ps2);
+       gsl_matrix_free(matrix);
+       gsl_permutation_free(permutation);
+       free(XiPhiR);
+       free(YiRhoR);
+       free(gam2);
+       free(pi2);
+       free(X2);
+       free(Y2);
+       free(dotProducts);
+}