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                /* Sparse symmetric matrices in triplet format */
#include "dsTMatrix.h"

SEXP dsTMatrix_validate(SEXP x)
{
    SEXP xiP = GET_SLOT(x, Matrix_iSym),
    xjP = GET_SLOT(x, Matrix_jSym),
    xxP = GET_SLOT(x, Matrix_xSym);
    int *dims = INTEGER(GET_SLOT(x, Matrix_DimSym));

    if (dims[0] != dims[1])
    return mkString(_("dsTMatrix must be square"));
    if (length(xiP) != length(xjP) || length(xjP) != length(xxP))
    return mkString(_("slots i, j and x must have the same length"));
    return ScalarLogical(1);
}

SEXP dsTMatrix_as_dsyMatrix(SEXP x)
{
    SEXP val = PROTECT(NEW_OBJECT(MAKE_CLASS("dsyMatrix"))),
    DimP = GET_SLOT(x, Matrix_DimSym),
    xiP = GET_SLOT(x, Matrix_iSym);
    int k, n = INTEGER(DimP)[1], nnz = length(xiP);
    int *xi = INTEGER(xiP), *xj = INTEGER(GET_SLOT(x, Matrix_jSym)),
    sz = n * n;
    double *tx = REAL(ALLOC_SLOT(val, Matrix_xSym, REALSXP, sz)),
    *xx = REAL(GET_SLOT(x, Matrix_xSym));
    
    SET_SLOT(val, Matrix_DimSym, duplicate(DimP));
    SET_SLOT(val, Matrix_uploSym, duplicate(GET_SLOT(x, Matrix_uploSym)));
    AZERO(tx, sz);
    for (k = 0; k < nnz; k++) tx[xi[k] + xj[k] * n] = xx[k];
    UNPROTECT(1);
    return val;
}

SEXP dsTMatrix_as_dsCMatrix(SEXP x)
{
    SEXP val = PROTECT(NEW_OBJECT(MAKE_CLASS("dsCMatrix"))),
    dimP = GET_SLOT(x, Matrix_DimSym),
    xiP = GET_SLOT(x, Matrix_iSym);
    int n = INTEGER(dimP)[0],
    nnz = length(xiP);
    int *ti = Calloc(nnz, int),
        *vp = INTEGER(ALLOC_SLOT(val, Matrix_pSym, INTSXP, n + 1));
    double *tx = Calloc(nnz, double);
    
    SET_SLOT(val, Matrix_uploSym, duplicate(GET_SLOT(x, Matrix_uploSym)));
    SET_SLOT(val, Matrix_DimSym, duplicate(dimP));
    triplet_to_col(n, n, nnz, INTEGER(xiP),
           INTEGER(GET_SLOT(x, Matrix_jSym)),
           REAL(GET_SLOT(x, Matrix_xSym)),
           vp, ti, tx);
    nnz = vp[n];
    Memcpy(INTEGER(ALLOC_SLOT(val, Matrix_iSym, INTSXP, nnz)), ti, nnz);
    Memcpy(REAL(ALLOC_SLOT(val, Matrix_iSym, REALSXP, nnz)), tx, nnz);     
    Free(ti); Free(tx);
    UNPROTECT(1);
    return val;
}