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                /* Sparse triangular logical matrices */
#include "ltCMatrix.h"

/**
 * Check the validity of the slots of an ltCMatrix object
 *
 * @param x Pointer to an ltCMatrix object
 *
 * @return an SEXP that is either TRUE or a character string
 * describing the way in which the object failed the validity check
 */
SEXP ltCMatrix_validate(SEXP x)
{
    SEXP val = triangularMatrix_validate(x);
    if(isString(val))
    return(val);
    else {
    /* FIXME needed? ltC* inherits from lgC* which does this in validate*/
    SEXP pslot = GET_SLOT(x, Matrix_pSym),
        islot = GET_SLOT(x, Matrix_iSym);
    int
        ncol = length(pslot) - 1,
        *xp = INTEGER(pslot),
        *xi = INTEGER(islot);

    if (csc_unsorted_columns(ncol, xp, xi))
        csc_sort_columns(ncol, xp, xi, (double *) NULL);
    return ScalarLogical(1);
    }
}

/**
 * Transpose an ltCMatrix
 *
 * @param x Pointer to an ltCMatrix object
 *
 * @return the transpose of x.  It represents the same matrix but is
 * stored in the opposite triangle.
 */
SEXP ltCMatrix_trans(SEXP x)
{
    SEXP Xi = GET_SLOT(x, Matrix_iSym),
    ans = PROTECT(NEW_OBJECT(MAKE_CLASS("ltCMatrix"))),
    xdn = GET_SLOT(x, Matrix_DimNamesSym);
    SEXP adn = ALLOC_SLOT(ans, Matrix_DimNamesSym, VECSXP, 2);
    int *adims = INTEGER(ALLOC_SLOT(ans, Matrix_DimSym, INTSXP, 2)),
    *xdims = INTEGER(GET_SLOT(x, Matrix_DimSym)),
    up = uplo_P(x)[0] == 'U';
    int m = xdims[0], n = xdims[1], nz = length(Xi);
    int *xj = expand_cmprPt(n, INTEGER(GET_SLOT(x, Matrix_pSym)),
                Calloc(nz, int));

    adims[0] = n; adims[1] = m;
    SET_VECTOR_ELT(adn, 0, VECTOR_ELT(xdn, 1));
    SET_VECTOR_ELT(adn, 1, VECTOR_ELT(xdn, 0));
    SET_SLOT(ans, Matrix_uploSym, mkString(up ? "L" : "U"));
    SET_SLOT(ans, Matrix_diagSym, duplicate(GET_SLOT(x, Matrix_diagSym)));
    triplet_to_col(n, m, nz, xj, INTEGER(Xi), (double *) NULL,
           INTEGER(ALLOC_SLOT(ans, Matrix_pSym, INTSXP,  m + 1)),
           INTEGER(ALLOC_SLOT(ans, Matrix_iSym, INTSXP,  nz)),
           (double *) NULL);
    Free(xj);
    UNPROTECT(1);
    return ans;
}

/**
 * Solve  one  of the matrix equations  op(A)*C = B, or
 * C*op(A) = B where A is a square ltCMatrix and B and C are lgCMatrix
 * objects.
 *
 * @param side LFT or RGT
 * @param transa TRN or NTR
 * @param A pointer to an ltCMatrix object
 * @param B pointer to an lgCMatrix object
 * @param C pointer to an lgCMatrix object
 */
void
ltClgCsm(enum CBLAS_SIDE side, enum CBLAS_TRANSPOSE transa,
     SEXP A, SEXP B, SEXP C)
{
    error(_("code not yet written"));
}