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                /* Sparse matrices in triplet form */
#include "Tsparse.h"
#include "chm_common.h"

SEXP Tsparse_validate(SEXP x)
{
    /* NB: we do *NOT* check a potential 'x' slot here, at all */
    SEXP
    islot = GET_SLOT(x, Matrix_iSym),
    jslot = GET_SLOT(x, Matrix_jSym),
    dimslot = GET_SLOT(x, Matrix_DimSym);
    int j,
    nrow = INTEGER(dimslot)[0],
    ncol = INTEGER(dimslot)[1],
    nnz = length(islot),
    *xj = INTEGER(jslot),
    *xi = INTEGER(islot);

    if (length(jslot) != nnz)
    return mkString(_("lengths of slots i and j must match"));
    /* FIXME: this is checked in super class -- no need to do here: */
    if (length(dimslot) != 2)
    return mkString(_("slot Dim must have length 2"));

    for (j = 0; j < nnz; j++) {
    if (xi[j] < 0 || xi[j] >= nrow)
        return mkString(_("all row indices must be between 0 and nrow-1"));
    if (xj[j] < 0 || xj[j] >= ncol)
        return mkString(_("all column indices must be between 0 and ncol-1"));
    }
    return ScalarLogical(1);
}

SEXP Tsparse_to_Csparse(SEXP x, SEXP tri)
{
    CHM_TR chxt = AS_CHM_TR(x);
    CHM_SP chxs = cholmod_triplet_to_sparse(chxt, chxt->nnz, &c);
    int tr = asLogical(tri);
    int Rkind = (chxt->xtype != CHOLMOD_PATTERN) ? Real_kind(x) : 0;
    R_CheckStack();

    return chm_sparse_to_SEXP(chxs, 1,
                  tr ? ((*uplo_P(x) == 'U') ? 1 : -1) : 0,
                  Rkind, tr ? diag_P(x) : "",
                  GET_SLOT(x, Matrix_DimNamesSym));
}

/* speedup utility, needed e.g. after subsetting: */
SEXP Tsparse_to_tCsparse(SEXP x, SEXP uplo, SEXP diag)
{
    CHM_TR chxt = AS_CHM_TR(x);
    CHM_SP chxs = cholmod_triplet_to_sparse(chxt, chxt->nnz, &c);
    int Rkind = (chxt->xtype != CHOLMOD_PATTERN) ? Real_kind(x) : 0;
    R_CheckStack();

    return chm_sparse_to_SEXP(chxs, 1,
                  /* uploT = */ (*CHAR(asChar(uplo)) == 'U')? 1: -1,
                  Rkind,
                  /* diag = */ CHAR(STRING_ELT(diag, 0)),
                  GET_SLOT(x, Matrix_DimNamesSym));
}

SEXP Tsparse_diagU2N(SEXP x)
{
    char *valid[] = {"dtTMatrix", /* 0 */
             "ltTMatrix", /* 1 */
             "ntTMatrix", /* 2 : no x slot */
             "ztTMatrix", /* 3 */
             ""};
/* #define xSXP(iTyp) ((iTyp == 0) ? REALSXP : ((iTyp == 1) ? LGLSXP : /\* else *\/ CPLXSXP)); */
/* #define xTYPE(iTyp) ((iTyp == 0) ? double : ((iTyp == 1) ? int : /\* else *\/ Rcomplex)); */
    int ctype = Matrix_check_class(class_P(x), valid);

    if (ctype < 0 || *diag_P(x) != 'U') {
    /* "trivially fast" when not triangular (<==> no 'diag' slot),
       or not *unit* triangular */
    return (x);
    }
    else { /* instead of going to Csparse -> Cholmod -> Csparse -> Tsparse, work directly: */
    int i, n = INTEGER(GET_SLOT(x, Matrix_DimSym))[0],
        nnz = length(GET_SLOT(x, Matrix_iSym)),
        new_n = nnz + n;
    SEXP ans = PROTECT(NEW_OBJECT(MAKE_CLASS(class_P(x))));
    int *islot = INTEGER(ALLOC_SLOT(ans, Matrix_iSym, INTSXP, new_n)),
        *jslot = INTEGER(ALLOC_SLOT(ans, Matrix_jSym, INTSXP, new_n));

    slot_dup(ans, x, Matrix_DimSym);
    SET_DimNames(ans, x);
    slot_dup(ans, x, Matrix_uploSym);
    SET_SLOT(ans, Matrix_diagSym, mkString("N"));

    /* Build the new i- and j- slots : first copy the current : */
    Memcpy(islot, INTEGER(GET_SLOT(x, Matrix_iSym)), nnz);
    Memcpy(jslot, INTEGER(GET_SLOT(x, Matrix_jSym)), nnz);
    /* then, add the new (i,j) slot entries: */
    for(i = 0; i < n; i++) {
        islot[i + nnz] = i;
        jslot[i + nnz] = i;
    }

    /* build the new x-slot : */
    switch(ctype) {
    case 0: { /* "d" */
        double *x_new = REAL(ALLOC_SLOT(ans, Matrix_xSym,
                        REALSXP, new_n));
        Memcpy(x_new, REAL(GET_SLOT(x, Matrix_xSym)), nnz);
        for(i = 0; i < n; i++) /* add  x[i,i] = 1. */
        x_new[i + nnz] = 1.;
        break;
    }
    case 1: { /* "l" */
        int *x_new = LOGICAL(ALLOC_SLOT(ans, Matrix_xSym,
                        LGLSXP, new_n));
        Memcpy(x_new, LOGICAL(GET_SLOT(x, Matrix_xSym)), nnz);
        for(i = 0; i < n; i++) /* add  x[i,i] = 1 (= TRUE) */
        x_new[i + nnz] = 1;
        break;
    }
    case 2: /* "n" */
        /* nothing to do here */
        break;

    case 3: { /* "z" */
        Rcomplex *x_new = COMPLEX(ALLOC_SLOT(ans, Matrix_xSym,
                         CPLXSXP, new_n));
        Memcpy(x_new, COMPLEX(GET_SLOT(x, Matrix_xSym)), nnz);
        for(i = 0; i < n; i++) /* add  x[i,i] = 1 (= TRUE) */
        x_new[i + nnz] = (Rcomplex) {1., 0.};
        break;
    }

    }/* switch() */

    UNPROTECT(1);
    return ans;
    }
}