Пример #1
0
static PyObject *simplex(PyObject *self, PyObject *args,
    PyObject *kwrds)
{
    matrix *c, *h, *b=NULL, *x=NULL, *z=NULL, *y=NULL;
    PyObject *G, *A=NULL, *t=NULL;
    glp_prob *lp;
    glp_smcp *options = NULL;
    pysmcp *smcpParm = NULL;
    int m, n, p, i, j, k, nnz, nnzmax, *rn=NULL, *cn=NULL;
    double *a=NULL, val;
    char *kwlist[] = {"c", "G", "h", "A", "b","options", NULL};

    if (!PyArg_ParseTupleAndKeywords(args, kwrds, "OOO|OOO!", kwlist, &c,
        &G, &h, &A, &b,&smcp_t,&smcpParm)) return NULL;

    if ((Matrix_Check(G) && MAT_ID(G) != DOUBLE) ||
        (SpMatrix_Check(G) && SP_ID(G) != DOUBLE) ||
        (!Matrix_Check(G) && !SpMatrix_Check(G))){
        PyErr_SetString(PyExc_TypeError, "G must be a 'd' matrix");
        return NULL;
    }
    if ((m = Matrix_Check(G) ? MAT_NROWS(G) : SP_NROWS(G)) <= 0)
        err_p_int("m");
    if ((n = Matrix_Check(G) ? MAT_NCOLS(G) : SP_NCOLS(G)) <= 0)
        err_p_int("n");

    if (!Matrix_Check(h) || h->id != DOUBLE) err_dbl_mtrx("h");
    if (h->nrows != m || h->ncols != 1){
        PyErr_SetString(PyExc_ValueError, "incompatible dimensions");
        return NULL;
    }

    if (A){
        if ((Matrix_Check(A) && MAT_ID(A) != DOUBLE) ||
            (SpMatrix_Check(A) && SP_ID(A) != DOUBLE) ||
            (!Matrix_Check(A) && !SpMatrix_Check(A))){
                PyErr_SetString(PyExc_ValueError, "A must be a dense "
                    "'d' matrix or a general sparse matrix");
                return NULL;
	}
        if ((p = Matrix_Check(A) ? MAT_NROWS(A) : SP_NROWS(A)) < 0)
            err_p_int("p");
        if ((Matrix_Check(A) ? MAT_NCOLS(A) : SP_NCOLS(A)) != n){
            PyErr_SetString(PyExc_ValueError, "incompatible "
                "dimensions");
            return NULL;
	}
    }
    else p = 0;

    if (b && (!Matrix_Check(b) || b->id != DOUBLE)) err_dbl_mtrx("b");
    if ((b && (b->nrows != p || b->ncols != 1)) || (!b && p !=0 )){
        PyErr_SetString(PyExc_ValueError, "incompatible dimensions");
        return NULL;
    }
    if(!smcpParm) 
    {
      smcpParm = (pysmcp*)malloc(sizeof(*smcpParm));
      glp_init_smcp(&(smcpParm->obj));
    }
    if(smcpParm) 
    {
      Py_INCREF(smcpParm);
      options = &smcpParm->obj;
      options->presolve = 1;
    }

    lp = glp_create_prob();
    glp_add_rows(lp, m+p);
    glp_add_cols(lp, n);

    for (i=0; i<n; i++){
        glp_set_obj_coef(lp, i+1, MAT_BUFD(c)[i]);
        glp_set_col_bnds(lp, i+1, GLP_FR, 0.0, 0.0);
    }
    for (i=0; i<m; i++)
        glp_set_row_bnds(lp, i+1, GLP_UP, 0.0, MAT_BUFD(h)[i]);
    for (i=0; i<p; i++)
        glp_set_row_bnds(lp, i+m+1, GLP_FX, MAT_BUFD(b)[i],
            MAT_BUFD(b)[i]);

    nnzmax = (SpMatrix_Check(G) ? SP_NNZ(G) : m*n ) +
        ((A && SpMatrix_Check(A)) ? SP_NNZ(A) : p*n);
    a = (double *) calloc(nnzmax+1, sizeof(double));
    rn = (int *) calloc(nnzmax+1, sizeof(int));
    cn = (int *) calloc(nnzmax+1, sizeof(int));
    if (!a || !rn || !cn){
        free(a);  free(rn);  free(cn);  glp_delete_prob(lp);
        return PyErr_NoMemory();
    }

    nnz = 0;
    if (SpMatrix_Check(G)) {
        for (j=0; j<n; j++) for (k=SP_COL(G)[j]; k<SP_COL(G)[j+1]; k++)
            if ((val = SP_VALD(G)[k]) != 0.0){
                a[1+nnz] = val;
                rn[1+nnz] = SP_ROW(G)[k]+1;
                cn[1+nnz] = j+1;
                nnz++;
            }
    }
    else for (j=0; j<n; j++) for (i=0; i<m; i++)
        if ((val = MAT_BUFD(G)[i+j*m]) != 0.0){
            a[1+nnz] = val;
            rn[1+nnz] = i+1;
            cn[1+nnz] = j+1;
            nnz++;
        }

    if (A && SpMatrix_Check(A)){
        for (j=0; j<n; j++) for (k=SP_COL(A)[j]; k<SP_COL(A)[j+1]; k++)
            if ((val = SP_VALD(A)[k]) != 0.0){
                a[1+nnz] = val;
                rn[1+nnz] = m+SP_ROW(A)[k]+1;
                cn[1+nnz] = j+1;
                nnz++;
            }
    }
    else for (j=0; j<n; j++) for (i=0; i<p; i++)
        if ((val = MAT_BUFD(A)[i+j*p]) != 0.0){
            a[1+nnz] = val;
            rn[1+nnz] = m+i+1;
            cn[1+nnz] = j+1;
            nnz++;
        }

    glp_load_matrix(lp, nnz, rn, cn, a);
    free(rn);  free(cn);  free(a);

    if (!(t = PyTuple_New(A ? 4 : 3))){
        glp_delete_prob(lp);
        return PyErr_NoMemory();
    }


    switch (glp_simplex(lp,options)){

        case 0:

            x = (matrix *) Matrix_New(n,1,DOUBLE);
            z = (matrix *) Matrix_New(m,1,DOUBLE);
            if (A) y = (matrix *) Matrix_New(p,1,DOUBLE);
            if (!x || !z || (A && !y)){
                Py_XDECREF(x);
                Py_XDECREF(z);
                Py_XDECREF(y);
                Py_XDECREF(t);
                Py_XDECREF(smcpParm);
                glp_delete_prob(lp);
                return PyErr_NoMemory();
            }

            set_output_string(t,"optimal");

            for (i=0; i<n; i++)
                MAT_BUFD(x)[i] = glp_get_col_prim(lp, i+1);
            PyTuple_SET_ITEM(t, 1, (PyObject *) x);

            for (i=0; i<m; i++)
                MAT_BUFD(z)[i] = -glp_get_row_dual(lp, i+1);
            PyTuple_SET_ITEM(t, 2, (PyObject *) z);

            if (A){
                for (i=0; i<p; i++)
                    MAT_BUFD(y)[i] = -glp_get_row_dual(lp, m+i+1);
                PyTuple_SET_ITEM(t, 3, (PyObject *) y);
            }

            Py_XDECREF(smcpParm);
            glp_delete_prob(lp);
            return (PyObject *) t;
        case GLP_EBADB:
            set_output_string(t,"incorrect initial basis");
            break;
        case GLP_ESING:
            set_output_string(t,"singular initial basis matrix");
            break;
        case GLP_ECOND:
            set_output_string(t,"ill-conditioned initial basis matrix");
            break;
        case GLP_EBOUND:
            set_output_string(t,"incorrect bounds");
            break;
        case GLP_EFAIL:
            set_output_string(t,"solver failure");
            break;
        case GLP_EOBJLL:
            set_output_string(t,"objective function reached lower limit");
            break;
        case GLP_EOBJUL:
            set_output_string(t,"objective function reached upper limit");
            break;
        case GLP_EITLIM:
            set_output_string(t,"iteration limit exceeded");
            break;
        case GLP_ETMLIM:
            set_output_string(t,"time limit exceeded");
            break;
        case GLP_ENOPFS:
            set_output_string(t,"primal infeasible");
            break;
        case GLP_ENODFS:
            set_output_string(t,"dual infeasible");
            break;
        default:
            set_output_string(t,"unknown");
            break;
    }

    Py_XDECREF(smcpParm);
    glp_delete_prob(lp);

    PyTuple_SET_ITEM(t, 1, Py_BuildValue(""));
    PyTuple_SET_ITEM(t, 2, Py_BuildValue(""));
    if (A) PyTuple_SET_ITEM(t, 3, Py_BuildValue(""));

    return (PyObject *) t;
}
Пример #2
0
static PyObject* splinsolve(PyObject *self, PyObject *args,
    PyObject *kwrds)
{
    spmatrix *A, *B, *X;
    matrix *P=NULL;
    int n, nnz;
    cholmod_sparse *Ac=NULL, *Bc=NULL, *Xc=NULL;
    cholmod_factor *L=NULL;
#if PY_MAJOR_VERSION >= 3
    int uplo_='L';
#endif
    char uplo='L';
    char *kwlist[] = {"A", "B", "p", "uplo", NULL};

    if (!set_options()) return NULL;
#if PY_MAJOR_VERSION >= 3
    if (!PyArg_ParseTupleAndKeywords(args, kwrds, "OO|OC", kwlist, &A,
        &B, &P, &uplo_)) return NULL;
    uplo = (char) uplo_;
#else
    if (!PyArg_ParseTupleAndKeywords(args, kwrds, "OO|Oc", kwlist, &A,
        &B, &P, &uplo)) return NULL;
#endif

    if (!SpMatrix_Check(A) || SP_NROWS(A) != SP_NCOLS(A))
        PY_ERR_TYPE("A is not a square sparse matrix");
    n = SP_NROWS(A);
    nnz = SP_NNZ(A);

    if (!SpMatrix_Check(B) || SP_ID(A) != SP_ID(B))
        PY_ERR_TYPE("B must be a sparse matrix of the same type as A");
    if (SP_NROWS(B) != n)
        PY_ERR(PyExc_ValueError, "incompatible dimensions for B");

    if (P) {
        if (!Matrix_Check(P) || MAT_ID(P) != INT) err_int_mtrx("p");
        if (MAT_LGT(P) != n) err_buf_len("p");
        if (!CHOL(check_perm)(P->buffer, n, n, &Common))
            PY_ERR(PyExc_ValueError, "not a valid permutation");
    }

    if (uplo != 'U' && uplo != 'L') err_char("uplo", "'L', 'U'");
    if (!(Ac = pack(A, uplo))) return PyErr_NoMemory();

    L = CHOL(analyze_p) (Ac, P ? MAT_BUFI(P): NULL, NULL, 0, &Common);
    if (Common.status != CHOLMOD_OK){
        CHOL(free_factor)(&L, &Common);
        CHOL(free_sparse)(&Ac, &Common);
        if (Common.status == CHOLMOD_OUT_OF_MEMORY)
            return PyErr_NoMemory();
        else {
            PyErr_SetString(PyExc_ValueError, "symbolic factorization "
                "failed");
            return NULL;
        }
    }

    CHOL(factorize) (Ac, L, &Common);
    CHOL(free_sparse)(&Ac, &Common);
    if (Common.status > 0) switch (Common.status) {
        case CHOLMOD_NOT_POSDEF:
            PyErr_SetObject(PyExc_ArithmeticError, Py_BuildValue("i",
                L->minor));
            CHOL(free_factor)(&L, &Common);
            return NULL;
            break;

        case CHOLMOD_DSMALL:
            /* This never happens unless we change the default value
             * of Common.dbound (0.0).  */
            if (L->is_ll)
                PyErr_Warn(PyExc_RuntimeWarning, "tiny diagonal "
                    "elements in L");
            else
                PyErr_Warn(PyExc_RuntimeWarning, "tiny diagonal "
                    "elements in D");
            break;

        default:
            PyErr_Warn(PyExc_UserWarning, "");
    }

    if (L->minor<n) {
        CHOL(free_factor)(&L, &Common);
        PY_ERR(PyExc_ArithmeticError, "singular matrix");
    }
    if (!(Bc = create_matrix(B))) {
      CHOL(free_factor)(&L, &Common);
      return PyErr_NoMemory();
    }

    Xc = CHOL(spsolve)(0, L, Bc, &Common);
    free_matrix(Bc);
    CHOL(free_factor)(&L, &Common);
    if (Common.status != CHOLMOD_OK){
        CHOL(free_sparse)(&Xc, &Common);
        if (Common.status == CHOLMOD_OUT_OF_MEMORY)
            return PyErr_NoMemory();
        else
            PY_ERR(PyExc_ValueError, "solve step failed");
    }

    if (!(X = SpMatrix_New(Xc->nrow, Xc->ncol,
        ((int_t*)Xc->p)[Xc->ncol], SP_ID(A)))) {
        CHOL(free_sparse)(&Xc, &Common);
        return PyErr_NoMemory();
    }
    memcpy(SP_COL(X), (int_t *) Xc->p, (Xc->ncol+1)*sizeof(int_t));
    memcpy(SP_ROW(X), (int_t *) Xc->i,
        ((int_t *) Xc->p)[Xc->ncol]*sizeof(int_t));
    memcpy(SP_VAL(X), (double *) Xc->x,
        ((int_t *) Xc->p)[Xc->ncol]*E_SIZE[SP_ID(X)]);
    CHOL(free_sparse)(&Xc, &Common);
    return (PyObject *) X;
}
Пример #3
0
static PyObject* solve(PyObject *self, PyObject *args, PyObject *kwrds)
{
    matrix *B;
    PyObject *F;
    int i, n, oB=0, ldB=0, nrhs=-1, sys=0;
#if PY_MAJOR_VERSION >= 3
    const char *descr;
#else
    char *descr;
#endif
    char *kwlist[] = {"F", "B", "sys", "nrhs", "ldB", "offsetB", NULL};
    int sysvalues[] = { CHOLMOD_A, CHOLMOD_LDLt, CHOLMOD_LD,
        CHOLMOD_DLt, CHOLMOD_L, CHOLMOD_Lt, CHOLMOD_D, CHOLMOD_P,
        CHOLMOD_Pt };

    if (!set_options()) return NULL;

    if (!PyArg_ParseTupleAndKeywords(args, kwrds, "OO|iiii", kwlist,
        &F, &B, &sys, &nrhs, &ldB, &oB)) return NULL;

#if PY_MAJOR_VERSION >= 3
    if (!PyCapsule_CheckExact(F) || !(descr = PyCapsule_GetName(F)))
        err_CO("F");
    if (strncmp(descr, "CHOLMOD FACTOR", 14))
        PY_ERR_TYPE("F is not a CHOLMOD factor");
    cholmod_factor *L = (cholmod_factor *) PyCapsule_GetPointer(F, descr);
#else
    if (!PyCObject_Check(F)) err_CO("F");
    descr = PyCObject_GetDesc(F);
    if (!descr || strncmp(descr, "CHOLMOD FACTOR", 14))
        PY_ERR_TYPE("F is not a CHOLMOD factor");
    cholmod_factor *L = (cholmod_factor *) PyCObject_AsVoidPtr(F);
#endif
    if (L->xtype == CHOLMOD_PATTERN)
        PY_ERR(PyExc_ValueError, "called with symbolic factor");

    n = L->n;
    if (L->minor<n) PY_ERR(PyExc_ArithmeticError, "singular matrix");

    if (sys < 0 || sys > 8)
         PY_ERR(PyExc_ValueError, "invalid value for sys");

    if (!Matrix_Check(B) || MAT_ID(B) == INT ||
        (MAT_ID(B) == DOUBLE && L->xtype == CHOLMOD_COMPLEX) ||
        (MAT_ID(B) == COMPLEX && L->xtype == CHOLMOD_REAL))
            PY_ERR_TYPE("B must a dense matrix of the same numerical "
                "type as F");

    if (nrhs < 0) nrhs = MAT_NCOLS(B);
    if (n == 0 || nrhs == 0) return Py_BuildValue("");
    if (ldB == 0) ldB = MAX(1,MAT_NROWS(B));
    if (ldB < MAX(1,n)) err_ld("ldB");
    if (oB < 0) err_nn_int("offsetB");
    if (oB + (nrhs-1)*ldB + n > MAT_LGT(B)) err_buf_len("B");

    cholmod_dense *x;
    cholmod_dense *b = CHOL(allocate_dense)(n, 1, n,
        (MAT_ID(B) == DOUBLE ? CHOLMOD_REAL : CHOLMOD_COMPLEX),
        &Common);
    if (Common.status == CHOLMOD_OUT_OF_MEMORY) return PyErr_NoMemory();

    void *b_old = b->x;
    for (i=0; i<nrhs; i++){
        b->x = (unsigned char*)MAT_BUF(B) + (i*ldB + oB)*E_SIZE[MAT_ID(B)];
        x = CHOL(solve) (sysvalues[sys], L, b, &Common);
        if (Common.status != CHOLMOD_OK){
            PyErr_SetString(PyExc_ValueError, "solve step failed");
            CHOL(free_dense)(&x, &Common);
            CHOL(free_dense)(&b, &Common);
	    return NULL;
	}
	memcpy(b->x, x->x, n*E_SIZE[MAT_ID(B)]);
        CHOL(free_dense)(&x, &Common);
    }
    b->x = b_old;
    CHOL(free_dense)(&b, &Common);

    return Py_BuildValue("");
}
Пример #4
0
static PyObject* linsolve(PyObject *self, PyObject *args,
    PyObject *kwrds)
{
    spmatrix *A;
    matrix *B, *P=NULL;
    int i, n, nnz, oB=0, ldB=0, nrhs=-1;
    cholmod_sparse *Ac=NULL;
    cholmod_factor *L=NULL;
    cholmod_dense *x=NULL, *b=NULL;
    void *b_old;
#if PY_MAJOR_VERSION >= 3
    int uplo_ = 'L';
#endif
    char uplo='L';
    char *kwlist[] = {"A", "B", "p", "uplo", "nrhs", "ldB", "offsetB",
        NULL};

    if (!set_options()) return NULL;
#if PY_MAJOR_VERSION >= 3
    if (!PyArg_ParseTupleAndKeywords(args, kwrds, "OO|OCiii", kwlist,
        &A,  &B, &P, &uplo_, &nrhs, &ldB, &oB)) return NULL;
    uplo = (char) uplo_;
#else
    if (!PyArg_ParseTupleAndKeywords(args, kwrds, "OO|Ociii", kwlist,
        &A,  &B, &P, &uplo, &nrhs, &ldB, &oB)) return NULL;
#endif

    if (!SpMatrix_Check(A) || SP_NROWS(A) != SP_NCOLS(A))
        PY_ERR_TYPE("A is not a sparse matrix");
    n = SP_NROWS(A);
    nnz = SP_NNZ(A);

    if (!Matrix_Check(B) || MAT_ID(B) != SP_ID(A))
        PY_ERR_TYPE("B must be a dense matrix of the same numerical "
            "type as A");
    if (nrhs < 0) nrhs = MAT_NCOLS(B);
    if (n == 0 || nrhs == 0) return Py_BuildValue("");
    if (ldB == 0) ldB = MAX(1,MAT_NROWS(B));
    if (ldB < MAX(1,n)) err_ld("ldB");
    if (oB < 0) err_nn_int("offsetB");
    if (oB + (nrhs-1)*ldB + n > MAT_LGT(B)) err_buf_len("B");

    if (P) {
        if (!Matrix_Check(P) || MAT_ID(P) != INT) err_int_mtrx("p");
        if (MAT_LGT(P) != n) err_buf_len("p");
        if (!CHOL(check_perm)(P->buffer, n, n, &Common))
            PY_ERR(PyExc_ValueError, "not a valid permutation");
    }
    if (uplo != 'U' && uplo != 'L') err_char("uplo", "'L', 'U'");

    if (!(Ac = pack(A, uplo))) return PyErr_NoMemory();
    L = CHOL(analyze_p)(Ac, P ? MAT_BUFI(P): NULL, NULL, 0, &Common);
    if (Common.status != CHOLMOD_OK){
        free_matrix(Ac);
        CHOL(free_sparse)(&Ac, &Common);
        CHOL(free_factor)(&L, &Common);
        if (Common.status == CHOLMOD_OUT_OF_MEMORY)
            return PyErr_NoMemory();
        else {
            PyErr_SetString(PyExc_ValueError, "symbolic factorization "
                "failed");
            return NULL;
        }
    }

    CHOL(factorize) (Ac, L, &Common);
    CHOL(free_sparse)(&Ac, &Common);
    if (Common.status < 0) {
        CHOL(free_factor)(&L, &Common);
        switch (Common.status) {
            case CHOLMOD_OUT_OF_MEMORY:
                return PyErr_NoMemory();

            default:
                PyErr_SetString(PyExc_ValueError, "factorization "
                    "failed");
                return NULL;
        }
    }
    if (Common.status > 0) switch (Common.status) {
        case CHOLMOD_NOT_POSDEF:
            PyErr_SetObject(PyExc_ArithmeticError,
                Py_BuildValue("i", L->minor));
            CHOL(free_factor)(&L, &Common);
            return NULL;
            break;

        case CHOLMOD_DSMALL:
            /* This never happens unless we change the default value
             * of Common.dbound (0.0).  */
            if (L->is_ll)
                PyErr_Warn(PyExc_RuntimeWarning, "tiny diagonal "
                    "elements in L");
            else
                PyErr_Warn(PyExc_RuntimeWarning, "tiny diagonal "
                    "elements in D");
            break;

        default:
            PyErr_Warn(PyExc_UserWarning, "");
    }

    if (L->minor<n) {
        CHOL(free_factor)(&L, &Common);
        PY_ERR(PyExc_ArithmeticError, "singular matrix");
    }
    b = CHOL(allocate_dense)(n, 1, n, (MAT_ID(B) == DOUBLE ?
        CHOLMOD_REAL : CHOLMOD_COMPLEX) , &Common);
    if (Common.status == CHOLMOD_OUT_OF_MEMORY) {
        CHOL(free_factor)(&L, &Common);
        CHOL(free_dense)(&b, &Common);
        return PyErr_NoMemory();
    }
    b_old = b->x;
    for (i=0; i<nrhs; i++) {
        b->x = (unsigned char*)MAT_BUF(B) + (i*ldB + oB)*E_SIZE[MAT_ID(B)];
        x = CHOL(solve) (CHOLMOD_A, L, b, &Common);
        if (Common.status != CHOLMOD_OK){
            PyErr_SetString(PyExc_ValueError, "solve step failed");
            CHOL(free_factor)(&L, &Common);
            b->x = b_old;
            CHOL(free_dense)(&b, &Common);
            CHOL(free_dense)(&x, &Common);
            return NULL;
        }
        memcpy(b->x, x->x, SP_NROWS(A)*E_SIZE[MAT_ID(B)]);
        CHOL(free_dense)(&x, &Common);
    }
    b->x = b_old;
    CHOL(free_dense)(&b, &Common);
    CHOL(free_factor)(&L, &Common);
    return Py_BuildValue("");
}
Пример #5
0
static PyObject* symbolic(PyObject *self, PyObject *args,
    PyObject *kwrds)
{
    spmatrix *A;
    cholmod_sparse *Ac = NULL;
    cholmod_factor *L;
    matrix *P=NULL;
#if PY_MAJOR_VERSION >= 3
    int uplo_='L';
#endif
    char uplo='L';
    int n;
    char *kwlist[] = {"A", "p", "uplo", NULL};

    if (!set_options()) return NULL;

#if PY_MAJOR_VERSION >= 3
    if (!PyArg_ParseTupleAndKeywords(args, kwrds, "O|OC", kwlist, &A,
        &P, &uplo_)) return NULL;
    uplo = (char) uplo_;
#else
    if (!PyArg_ParseTupleAndKeywords(args, kwrds, "O|Oc", kwlist, &A,
        &P, &uplo)) return NULL;
#endif
    if (!SpMatrix_Check(A) || SP_NROWS(A) != SP_NCOLS(A))
        PY_ERR_TYPE("A is not a square sparse matrix");
    n = SP_NROWS(A);

    if (P) {
        if (!Matrix_Check(P) || MAT_ID(P) != INT) err_int_mtrx("p");
        if (MAT_LGT(P) != n) err_buf_len("p");
        if (!CHOL(check_perm)(P->buffer, n, n, &Common))
            PY_ERR(PyExc_ValueError, "p is not a valid permutation");
    }
    if (uplo != 'U' && uplo != 'L') err_char("uplo", "'L', 'U'");
    if (!(Ac = pack(A, uplo))) return PyErr_NoMemory();
    L = CHOL(analyze_p)(Ac, P ? MAT_BUFI(P): NULL, NULL, 0, &Common);
    CHOL(free_sparse)(&Ac, &Common);

    if (Common.status != CHOLMOD_OK){
        if (Common.status == CHOLMOD_OUT_OF_MEMORY)
            return PyErr_NoMemory();
        else{
            PyErr_SetString(PyExc_ValueError, "symbolic factorization "
                "failed");
            return NULL;
        }
    }
#if PY_MAJOR_VERSION >= 3
    return (PyObject *) PyCapsule_New((void *) L, SP_ID(A)==DOUBLE ?  
        (uplo == 'L' ?  "CHOLMOD FACTOR D L" : "CHOLMOD FACTOR D U") :
        (uplo == 'L' ?  "CHOLMOD FACTOR Z L" : "CHOLMOD FACTOR Z U"),
        (PyCapsule_Destructor) &cvxopt_free_cholmod_factor); 
#else
    return (PyObject *) PyCObject_FromVoidPtrAndDesc((void *) L,
        SP_ID(A)==DOUBLE ?  
        (uplo == 'L' ?  "CHOLMOD FACTOR D L" : "CHOLMOD FACTOR D U") :
        (uplo == 'L' ?  "CHOLMOD FACTOR Z L" : "CHOLMOD FACTOR Z U"),
	cvxopt_free_cholmod_factor);
#endif
}