void mexFunction
(
int nargout,
mxArray *pargout [ ],
int nargin,
const mxArray *pargin [ ]
)
{
double dummy = 0, beta [2], *px, *C, *Ct, *C2, *fil, *Zt, *zt, done=1.0, *zz, dzero=0.0;
cholmod_sparse Amatrix, *A, *Lsparse ;
cholmod_factor *L ;
cholmod_common Common, *cm ;
Int minor, *It2, *Jt2 ;
mwIndex l, k2, h, k, i, j, ik, *I, *J, *Jt, *It, *I2, *J2, lfi, *w, *w2, *r;
mwSize nnz, nnzlow, m, n;
int nz = 0;
mwSignedIndex one=1, lfi_si;
mxArray *Am, *Bm;
char *uplo="L", *trans="N";
/* ---------------------------------------------------------------------- */
/* Only one input. We have to find first the Cholesky factorization. */
/* start CHOLMOD and set parameters */
/* ---------------------------------------------------------------------- */
if (nargin == 1) {
cm = &Common ;
cholmod_l_start (cm) ;
sputil_config (SPUMONI, cm) ;
/* convert to packed LDL' when done */
cm->final_asis = FALSE ;
cm->final_super = FALSE ;
cm->final_ll = FALSE ;
cm->final_pack = TRUE ;
cm->final_monotonic = TRUE ;
/* since numerically zero entries are NOT dropped from the symbolic
* pattern, we DO need to drop entries that result from supernodal
* amalgamation. */
cm->final_resymbol = TRUE ;
cm->quick_return_if_not_posdef = (nargout < 2) ;
}
/* This will disable the supernodal LL', which will be slow. */
/* cm->supernodal = CHOLMOD_SIMPLICIAL ; */
/* ---------------------------------------------------------------------- */
/* get inputs */
/* ---------------------------------------------------------------------- */
if (nargin > 3)
{
mexErrMsgTxt ("usage: Z = sinv(A), or Z = sinv(LD, 1)") ;
}
n = mxGetM (pargin [0]) ;
m = mxGetM (pargin [0]) ;
if (!mxIsSparse (pargin [0]))
{
mexErrMsgTxt ("A must be sparse") ;
}
if (n != mxGetN (pargin [0]))
{
mexErrMsgTxt ("A must be square") ;
}
/* Only one input. We have to find first the Cholesky factorization. */
if (nargin == 1) {
/* get sparse matrix A, use tril(A) */
A = sputil_get_sparse (pargin [0], &Amatrix, &dummy, -1) ;
A->stype = -1 ; /* use lower part of A */
beta [0] = 0 ;
beta [1] = 0 ;
/* ---------------------------------------------------------------------- */
/* analyze and factorize */
/* ---------------------------------------------------------------------- */
L = cholmod_l_analyze (A, cm) ;
cholmod_l_factorize_p (A, beta, NULL, 0, L, cm) ;
if (cm->status != CHOLMOD_OK)
{
mexErrMsgTxt ("matrix is not positive definite") ;
}
/* ---------------------------------------------------------------------- */
/* convert L to a sparse matrix */
/* ---------------------------------------------------------------------- */
Lsparse = cholmod_l_factor_to_sparse (L, cm) ;
if (Lsparse->xtype == CHOLMOD_COMPLEX)
{
mexErrMsgTxt ("matrix is complex") ;
}
/* ---------------------------------------------------------------------- */
/* Set the sparse Cholesky factorization in Matlab format */
/* ---------------------------------------------------------------------- */
/*Am = sputil_put_sparse (&Lsparse, cm) ;
I = mxGetIr(Am);
J = mxGetJc(Am);
C = mxGetPr(Am);
nnz = mxGetNzmax(Am); */
It2 = Lsparse->i;
Jt2 = Lsparse->p;
Ct = Lsparse->x;
nnz = (mwSize) Lsparse->nzmax;
Am = mxCreateSparse(m, m, nnz, mxREAL) ;
I = mxGetIr(Am);
J = mxGetJc(Am);
C = mxGetPr(Am);
for (j = 0 ; j < n+1 ; j++) J[j] = (mwIndex) Jt2[j];
for ( i = 0 ; i < nnz ; i++) {
I[i] = (mwIndex) It2[i];
C[i] = Ct[i];
}
cholmod_l_free_sparse (&Lsparse, cm) ;
/*FILE *out1 = fopen( "output1.txt", "w" );
if( out1 != NULL )
fprintf( out1, "Hello %d\n", nnz );
fclose (out1);*/
} else {
/* The cholesky factorization is given as an input. */
/* We have to copy it into workspace */
It = mxGetIr(pargin [0]);
Jt = mxGetJc(pargin [0]);
Ct = mxGetPr(pargin [0]);
nnz = mxGetNzmax(pargin [0]);
Am = mxCreateSparse(m, m, nnz, mxREAL) ;
I = mxGetIr(Am);
J = mxGetJc(Am);
C = mxGetPr(Am);
for (j = 0 ; j < n+1 ; j++) J[j] = Jt[j];
for ( i = 0 ; i < nnz ; i++) {
I[i] = It[i];
C[i] = Ct[i];
}
}
/* Evaluate the sparse inverse */
C[nnz-1] = 1.0/C[J[m-1]]; /* set the last element of sparse inverse */
fil = mxCalloc((mwSize)1,sizeof(double));
zt = mxCalloc((mwSize)1,sizeof(double));
Zt = mxCalloc((mwSize)1,sizeof(double));
zz = mxCalloc((mwSize)1,sizeof(double));
for (j=m-2;j!=-1;j--){
lfi = J[j+1]-(J[j]+1);
/* if (lfi > 0) */
if ( J[j+1] > (J[j]+1) )
{
/* printf("lfi = %u \n ", lfi);
printf("lfi*double = %u \n", (mwSize)lfi*sizeof(double));
printf("lfi*lfi*double = %u \n", (mwSize)lfi*(mwSize)lfi*sizeof(double));
printf("\n \n");
*/
fil = mxRealloc(fil,(mwSize)lfi*sizeof(double));
for (i=0;i<lfi;i++) fil[i] = C[J[j]+i+1]; /* take the j'th lower triangular column of the Cholesky */
zt = mxRealloc(zt,(mwSize)lfi*sizeof(double)); /* memory for the sparse inverse elements to be evaluated */
Zt = mxRealloc(Zt,(mwSize)lfi*(mwSize)lfi*sizeof(double)); /* memory for the needed sparse inverse elements */
/* Set the lower triangular for Zt */
k2 = 0;
for (k=J[j]+1;k<J[j+1];k++){
ik = I[k];
h = k2;
for (l=J[ik];l<=J[ik+1];l++){
if (I[l] == I[ J[j]+h+1 ]){
Zt[h+lfi*k2] = C[l];
h++;
}
}
k2++;
}
/* evaluate zt = fil*Zt */
lfi_si = (mwSignedIndex) lfi;
dsymv(uplo, &lfi_si, &done, Zt, &lfi_si, fil, &one, &dzero, zt, &one);
/* Set the evaluated sparse inverse elements, zt, into C */
k=lfi-1;
for (i = J[j+1]-1; i!=J[j] ; i--){
C[i] = -zt[k];
k--;
}
/* evaluate the j'th diagonal of sparse inverse */
dgemv(trans, &one, &lfi_si, &done, fil, &one, zt, &one, &dzero, zz, &one);
C[J[j]] = 1.0/C[J[j]] + zz[0];
}
else
{
/* evaluate the j'th diagonal of sparse inverse */
C[J[j]] = 1.0/C[J[j]];
}
}
/* Free the temporary variables */
mxFree(fil);
mxFree(zt);
mxFree(Zt);
mxFree(zz);
/* ---------------------------------------------------------------------- */
/* Permute the elements according to r(q) = 1:n */
/* Done only if the Cholesky was evaluated here */
/* ---------------------------------------------------------------------- */
if (nargin == 1) {
Bm = mxCreateSparse(m, m, nnz, mxREAL) ;
It = mxGetIr(Bm);
Jt = mxGetJc(Bm);
Ct = mxGetPr(Bm); /* Ct = C(r,r) */
r = (mwIndex *) L->Perm; /* fill reducing ordering */
w = mxCalloc(m,sizeof(mwIndex)); /* column counts of Am */
/* count entries in each column of Bm */
for (j=0; j<m; j++){
k = r ? r[j] : j ; /* column j of Bm is column k of Am */
for (l=J[j] ; l<J[j+1] ; l++){
i = I[l];
ik = r ? r[i] : i ; /* row i of Bm is row ik of Am */
w[ max(ik,k) ]++;
}
}
cumsum2(Jt, w, m);
for (j=0; j<m; j++){
k = r ? r[j] : j ; /* column j of Bm is column k of Am */
for (l=J[j] ; l<J[j+1] ; l++){
i= I[l];
ik = r ? r[i] : i ; /* row i of Bm is row ik of Am */
It [k2 = w[max(ik,k)]++ ] = min(ik,k);
Ct[k2] = C[l];
}
}
mxFree(w);
/* ---------------------------------------------------------------------- */
/* Transpose the permuted (upper triangular) matrix Bm into Am */
/* (this way we get sorted columns) */
/* ---------------------------------------------------------------------- */
w = mxCalloc(m,sizeof(mwIndex));
for (i=0 ; i<Jt[m] ; i++) w[It[i]]++; /* row counts of Bm */
cumsum2(J, w, m); /* row pointers */
for (j=0 ; j<m ; j++){
for (i=Jt[j] ; i<Jt[j+1] ; i++){
I[ l=w[ It[i] ]++ ] = j;
C[l] = Ct[i];
}
}
mxFree(w);
mxDestroyArray(Bm);
}
/* ---------------------------------------------------------------------- */
/* Fill the upper triangle of the sparse inverse */
/* ---------------------------------------------------------------------- */
w = mxCalloc(m,sizeof(mwIndex)); /* workspace */
w2 = mxCalloc(m,sizeof(mwIndex)); /* workspace */
for (k=0;k<J[m];k++) w[I[k]]++; /* row counts of the lower triangular */
for (k=0;k<m;k++) w2[k] = w[k] + J[k+1] - J[k] - 1; /* column counts of the sparse inverse */
nnz = (mwSize)2*nnz - m; /* The number of nonzeros in Z */
pargout[0] = mxCreateSparse(m,m,nnz,mxREAL); /* The sparse matrix */
It = mxGetIr(pargout[0]);
Jt = mxGetJc(pargout[0]);
Ct = mxGetPr(pargout[0]);
cumsum2(Jt, w2, m); /* column starting points */
for (j = 0 ; j < m ; j++){ /* fill the upper triangular */
for (k = J[j] ; k < J[j+1] ; k++){
It[l = w2[ I[k]]++] = j ; /* place C(i,j) as entry Ct(j,i) */
if (Ct) Ct[l] = C[k] ;
}
}
for (j = 0 ; j < m ; j++){ /* fill the lower triangular */
for (k = J[j]+1 ; k < J[j+1] ; k++){
It[l = w2[j]++] = I[k] ; /* place C(j,i) as entry Ct(j,i) */
if (Ct) Ct[l] = C[k] ;
}
}
mxFree(w2);
mxFree(w);
/* ---------------------------------------------------------------------- */
/* return to MATLAB */
/* ---------------------------------------------------------------------- */
/* ---------------------------------------------------------------------- */
/* free workspace and the CHOLMOD L, except for what is copied to MATLAB */
/* ---------------------------------------------------------------------- */
if (nargin == 1) {
cholmod_l_free_factor (&L, cm) ;
cholmod_l_finish (cm) ;
cholmod_l_print_common (" ", cm) ;
}
mxDestroyArray(Am);
}
void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
{
// Allocate space.
double *Bbar, *delta_tilda_k, *delta_k;
double *tmp_stage, *tmp_stage_b;
double a, b;
mwSignedIndex p;
mwSignedIndex i;
#ifdef SUPERSAFE
mxArray* Bbar_copy = mxDuplicateArray(prhs[0]); // Safe
#else
mxArray* Bbar_copy = (prhs[0]); // Fast and Dangerous
#endif
// Read Input
p = mxGetM(prhs[0]);
Bbar = mxGetPr(Bbar_copy);
a = *(mxGetPr(prhs[1]));
b = *(mxGetPr(prhs[2]));
delta_tilda_k = mxGetPr(prhs[3]);
delta_k = mxGetPr(prhs[4]);
/* mexPrintf("a %f b %f Bbar(1,1) %f Bbar(1,3) %f", a, b, Bbar[0], Bbar[2]); */
/* print_arr(delta_tilda_k, p, "delta_tilda_k"); */
/* print_arr(delta_k, p, "delta_k"); */
#ifdef SAFE
tmp_stage = mxCalloc(p , sizeof(double));
tmp_stage_b = mxCalloc(p , sizeof(double));
#else
tmp_stage = mxGetPr(prhs[5]);
tmp_stage_b = mxGetPr(prhs[6]);
#endif
/* Stage 1: Bbar is symmetric.
*/
// tmp_stage = Bbar * delta_tilda_k;
dsymv("U", &p, &one, Bbar, &p, delta_tilda_k, &inc, &zero, tmp_stage, &inc);
// tmp_deno = a + b * (delta_k' * tmp_stage);
double tmp_deno = a + b * ddot(&p, delta_k, &inc, tmp_stage, &inc);
// tmp_stage_b = Bbar' * delta_k; == Bbar * delta_k (since Bbar is symmetric)
dsymv("U", &p, &one, Bbar, &p, delta_k, &inc, &zero, tmp_stage_b, &inc);
// Bbar = Bbar + (-b/tmp_deno) * tmp_stage * tmp_stage_b';
double b_by_tmp = -b / tmp_deno;
dger(&p, &p, &b_by_tmp, tmp_stage, &inc, tmp_stage_b, &inc, Bbar, &p);
/* Stage 2: Bbar is no longer symmetric.
Need to use dgemv instead of dsymv.
*/
// tmp_stage = Bbar * delta_k;
dgemv("N", &p, &p, &one, Bbar, &p, delta_k, &inc, &zero, tmp_stage, &inc);
// tmp_deno = a + b * (delta_tilda_k' * tmp_stage);
tmp_deno = a + b * ddot(&p, delta_tilda_k, &inc, tmp_stage, &inc);
// tmp_stage_b = Bbar' * delta_tilda_k;
dgemv("T", &p, &p, &one, Bbar, &p, delta_tilda_k, &inc, &zero, tmp_stage_b, &inc);
// Bbar = Bbar + (-b/tmp_deno) * tmp_stage * tmp_stage_b';
b_by_tmp = -b / tmp_deno;
dger(&p, &p, &b_by_tmp, tmp_stage, &inc, tmp_stage_b, &inc, Bbar, &p);
// In place edit Bbar and return the value.
plhs[0] = Bbar_copy;
#ifdef SAFE
mxFree(tmp_stage);
mxFree(tmp_stage_b);
#endif
}
// Sample factor vectors
// Function written from perspective of sampling user factor vectors with cross-topics
// Switch roles of user-item inputs to sample item factor vectors
void sampleTopicFactorVectors(uint32_t* items, double* resids, const mxArray* exampsByUser,
int KU, int KM, int numUsers, int numItems, double invSigmaSqd,
ptrdiff_t numTopicFacs, double* LambdaU, double* muU, double* c, double* d,
uint32_t* zU, uint32_t* zM){
// Array of random number generators
gsl_rng** rngs = getRngArray();
// Extract internals of jagged arrays
uint32_t** userExamps;
mwSize* userLens;
unpackJagged(exampsByUser, &userExamps, &userLens, numUsers);
ptrdiff_t numTopicFacsSqd = numTopicFacs*numTopicFacs;
ptrdiff_t numTopicFacsTimesNumItems = numTopicFacs*numItems;
ptrdiff_t numTopicFacsTimesNumUsers = numTopicFacs*numUsers;
// BLAS constants
char uplo[] = "U";
char trans[] = "N";
char diag[] = "N";
ptrdiff_t oneInt = 1;
double oneDbl = 1;
double zeroDbl = 0;
// Compute muBase = LambdaU*muU
double* muBase = mxMalloc(numTopicFacs*sizeof(*muBase));
dsymv(uplo, &numTopicFacs, &oneDbl, LambdaU, &numTopicFacs, muU, &oneInt, &zeroDbl, muBase, &oneInt);
// Allocate memory for new mean and precision parameters
double** muNew[MAX_NUM_THREADS];
double** LambdaNew[MAX_NUM_THREADS];
for(int thread = 0; thread < MAX_NUM_THREADS; thread++){
muNew[thread] = mxMalloc(KM*sizeof(**muNew));
LambdaNew[thread] = mxMalloc(KM*sizeof(**LambdaNew));
for(int i = 0; i < KM; i++){
muNew[thread][i] = mxMalloc(numTopicFacs*sizeof(***muNew));
LambdaNew[thread][i] = mxMalloc(numTopicFacsSqd*sizeof(***LambdaNew));
}
}
#pragma omp parallel for
for(int u = 0; u < numUsers; u++){
int thread = omp_get_thread_num();
for(int i = 0; i < KM; i++){
// Initialize new mean to muBase
dcopy(&numTopicFacs, muBase, &oneInt, muNew[thread][i], &oneInt);
// Initialize new precision to LambdaU
dcopy(&numTopicFacsSqd, LambdaU, &oneInt, LambdaNew[thread][i], &oneInt);
}
// Iterate over user's examples
mxArray* exampsArray = mxGetCell(exampsByUser, u);
mwSize len = mxGetN(exampsArray);
uint32_t* examps = (uint32_t*) mxGetData(exampsArray);
for(int j = 0; j < len; j++){
uint32_t e = examps[j]-1;
int m = items[e]-1;
int userTop = zU[e]-1;
int itemTop = zM[e]-1;
// Item vector for this rated item
double* dVec = d + m*numTopicFacs + userTop*numTopicFacsTimesNumItems;
// Compute posterior sufficient statistics for factor vector
// Add resid * dVec/sigmaSqd to muNew
double resid = resids[e];
resid *= invSigmaSqd;
daxpy(&numTopicFacs, &resid, dVec, &oneInt, muNew[thread][itemTop], &oneInt);
// Add (dVec * dVec^t)/sigmaSqd to LambdaNew
// Exploit symmetric structure of LambdaNew
dsyr(uplo, &numTopicFacs, &invSigmaSqd, dVec, &oneInt, LambdaNew[thread][itemTop],
&numTopicFacs);
}
for(int i = 0; i < KM; i++){
// Compute upper Cholesky factor of LambdaNew
ptrdiff_t info;
dpotrf(uplo, &numTopicFacs, LambdaNew[thread][i], &numTopicFacs, &info);
// Solve for (LambdaNew)^-1*muNew using Cholesky factor
dpotrs(uplo, &numTopicFacs, &oneInt, LambdaNew[thread][i], &numTopicFacs, muNew[thread][i],
&numTopicFacs, &info);
// Sample vector of N(0,1) variables
gsl_rng* rng = rngs[thread];
double* cVec = c + u*numTopicFacs + i*numTopicFacsTimesNumUsers;
for(int f = 0; f < numTopicFacs; f++)
cVec[f] = gsl_ran_gaussian(rng, 1);
// Solve for (chol(LambdaNew,'U'))^-1*N(0,1)
dtrtrs(uplo, trans, diag, &numTopicFacs, &oneInt, LambdaNew[thread][i],
&numTopicFacs, cVec, &numTopicFacs, &info);
// Add muNew to aVec
daxpy(&numTopicFacs, &oneDbl, muNew[thread][i], &oneInt, cVec, &oneInt);
}
}
// Clean up
mxFree(userExamps);
mxFree(userLens);
mxFree(muBase);
for(int thread = 0; thread < MAX_NUM_THREADS; thread++){
for(int i = 0; i < KM; i++){
mxFree(muNew[thread][i]);
mxFree(LambdaNew[thread][i]);
}
mxFree(muNew[thread]);
mxFree(LambdaNew[thread]);
}
}
void toast::lapack::symv ( char * UPLO, int * N, double * ALPHA, double * A, int * LDA, double * X, int * INCX, double * BETA, double * Y, int * INCY ) {
dsymv ( UPLO, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY );
return;
}
