/*
 * Python-C wrapper of FITPACK (by P. Dierckx) (in netlib known as dierckx)
 * Author: Pearu Peterson <pearu@ioc.ee>
 * June 1.-4., 1999
 * June 7. 1999
 * $Revision$
 * $Date$
 */

/*  module_methods:
 * {"_curfit", fitpack_curfit, METH_VARARGS, doc_curfit},
 * {"_spl_", fitpack_spl_, METH_VARARGS, doc_spl_},
 * {"_splint", fitpack_splint, METH_VARARGS, doc_splint},
 * {"_sproot", fitpack_sproot, METH_VARARGS, doc_sproot},
 * {"_spalde", fitpack_spalde, METH_VARARGS, doc_spalde},
 * {"_parcur", fitpack_parcur, METH_VARARGS, doc_parcur},
 * {"_surfit", fitpack_surfit, METH_VARARGS, doc_surfit},
 * {"_bispev", fitpack_bispev, METH_VARARGS, doc_bispev},
 * {"_insert", fitpack_insert, METH_VARARGS, doc_insert},
 */

/* link libraries: (one item per line)
   ddierckx
 */
/* python files: (to be imported to Multipack.py)
   fitpack.py
 */

#if defined(UPPERCASE_FORTRAN)
	#if defined(NO_APPEND_FORTRAN)
	/* nothing to do */
	#else
		#define CURFIT CURFIT_
		#define PERCUR PERCUR_
		#define SPALDE SPALDE_
		#define SPLDER SPLDER_
		#define SPLEV  SPLEV_
		#define SPLINT SPLINT_
		#define SPROOT SPROOT_
		#define PARCUR PARCUR_
		#define CLOCUR CLOCUR_
		#define SURFIT SURFIT_
		#define BISPEV BISPEV_
		#define PARDER PARDER_
		#define INSERT INSERT_
	#endif
#else
	#if defined(NO_APPEND_FORTRAN)
		#define CURFIT curfit
		#define PERCUR percur
		#define SPALDE spalde
		#define SPLDER splder
		#define SPLEV splev
		#define SPLINT splint
		#define SPROOT sproot
		#define PARCUR parcur
		#define CLOCUR clocur
		#define SURFIT surfit
		#define BISPEV bispev
		#define PARDER parder
		#define INSERT insert
	#else
		#define CURFIT curfit_
		#define PERCUR percur_
		#define SPALDE spalde_
		#define SPLDER splder_
		#define SPLEV splev_
		#define SPLINT splint_
		#define SPROOT sproot_
		#define PARCUR parcur_
		#define CLOCUR clocur_
		#define SURFIT surfit_
		#define BISPEV bispev_
		#define PARDER parder_
		#define INSERT insert_
	#endif
#endif

void CURFIT(int*,int*,double*,double*,double*,double*,
        double*,int*,double*,int*,int*,double*,double*,
        double*,double*,int*,int*,int*);
void PERCUR(int*,int*,double*,double*,double*,int*,
        double*,int*,int*,double*,double*,double*,
        double*,int*,int*,int*);
void SPALDE(double*,int*,double*,int*,double*,double*,int*);
void SPLDER(double*,int*,double*,int*,int*,double*,
        double*,int*,int*,double*,int*);
void SPLEV(double*,int*,double*,int*,double*,double*,int*,int*,int*);
double SPLINT(double*,int*,double*,int*,double*,double*,double*);
void SPROOT(double*,int*,double*,double*,int*,int*,int*);
void PARCUR(int*,int*,int*,int*,double*,int*,double*,
        double*,double*,double*,int*,double*,int*,int*,
        double*,int*,double*,double*,double*,int*,int*,int*);
void CLOCUR(int*,int*,int*,int*,double*,int*,double*,
        double*,int*,double*,int*,int*,double*,int*,
        double*,double*,double*,int*,int*,int*);
void SURFIT(int*,int*,double*,double*,double*,double*,
        double*,double*,double*,double*,int*,int*,double*,
        int*,int*,int*,double*,int*,double*,int*,double*,
        double*,double*,double*,int*,double*,int*,int*,int*,int*);
void BISPEV(double*,int*,double*,int*,double*,int*,int*,
        double*,int*,double*,int*,double*,double*,int*,
        int*,int*,int*);
void PARDER(double*,int*,double*,int*,double*,int*,int*,
        int*,int*,double*,int*,double*,int*,double*,
        double*,int*,int*,int*,int*);
void INSERT(int*,double*,int*,double*,int*,double*,double*,
        int*,double*,int*,int*);

/* Note that curev, cualde need no interface. */

static char doc_bispev[] = " [z,ier] = _bispev(tx,ty,c,kx,ky,x,y,nux,nuy)";
static PyObject *
fitpack_bispev(PyObject *dummy, PyObject *args)
{
    int nx, ny, kx, ky, mx, my, lwrk, *iwrk, kwrk, ier, lwa, nux, nuy;
    npy_intp mxy;
    double *tx, *ty, *c, *x, *y, *z, *wrk, *wa = NULL;
    PyArrayObject *ap_x = NULL, *ap_y = NULL, *ap_z = NULL, *ap_tx = NULL;
    PyArrayObject *ap_ty = NULL, *ap_c = NULL;
    PyObject *x_py = NULL, *y_py = NULL, *c_py = NULL, *tx_py = NULL, *ty_py = NULL;

    if (!PyArg_ParseTuple(args, "OOOiiOOii",&tx_py,&ty_py,&c_py,&kx,&ky,
                &x_py,&y_py,&nux,&nuy)) {
        return NULL;
    }
    ap_x = (PyArrayObject *)PyArray_ContiguousFromObject(x_py, NPY_DOUBLE, 0, 1);
    ap_y = (PyArrayObject *)PyArray_ContiguousFromObject(y_py, NPY_DOUBLE, 0, 1);
    ap_c = (PyArrayObject *)PyArray_ContiguousFromObject(c_py, NPY_DOUBLE, 0, 1);
    ap_tx = (PyArrayObject *)PyArray_ContiguousFromObject(tx_py, NPY_DOUBLE, 0, 1);
    ap_ty = (PyArrayObject *)PyArray_ContiguousFromObject(ty_py, NPY_DOUBLE, 0, 1);
    if (ap_x == NULL
            || ap_y == NULL
            || ap_c == NULL
            || ap_tx == NULL
            || ap_ty == NULL) {
        goto fail;
    }
    x = (double *) ap_x->data;
    y = (double *) ap_y->data;
    c = (double *) ap_c->data;
    tx = (double *) ap_tx->data;
    ty = (double *) ap_ty->data;
    nx = ap_tx->dimensions[0];
    ny = ap_ty->dimensions[0];
    mx = ap_x->dimensions[0];
    my = ap_y->dimensions[0];
    mxy = mx*my;
    ap_z = (PyArrayObject *)PyArray_SimpleNew(1,&mxy,NPY_DOUBLE);
    z = (double *) ap_z->data;
    if (nux || nuy) {
        lwrk = mx*(kx + 1 - nux) + my*(ky + 1 - nuy) + (nx - kx - 1)*(ny - ky - 1);
    }
    else {
        lwrk = mx*(kx + 1) + my*(ky + 1);
    }
    kwrk = mx + my;
    lwa = lwrk + kwrk;
    if ((wa = (double *)malloc(lwa*sizeof(double))) == NULL) {
        PyErr_NoMemory();
        goto fail;
    }
    wrk = wa;
    iwrk = (int *)(wrk + lwrk);
    if (nux || nuy) {
        PARDER(tx, &nx, ty, &ny, c, &kx, &ky, &nux, &nuy, x, &mx, y, &my, z,
                wrk, &lwrk, iwrk, &kwrk, &ier);
    }
    else {
        BISPEV(tx, &nx, ty, &ny, c, &kx, &ky, x, &mx, y, &my, z, wrk, &lwrk,
                iwrk, &kwrk, &ier);
    }

    if (wa) {
        free(wa);
    }
    Py_DECREF(ap_x);
    Py_DECREF(ap_y);
    Py_DECREF(ap_c);
    Py_DECREF(ap_tx);
    Py_DECREF(ap_ty);
    return Py_BuildValue("Ni",PyArray_Return(ap_z),ier);

fail:
    if (wa) {
        free(wa);
    }
    Py_XDECREF(ap_x);
    Py_XDECREF(ap_y);
    Py_XDECREF(ap_z);
    Py_XDECREF(ap_c);
    Py_XDECREF(ap_tx);
    Py_XDECREF(ap_ty);
    return NULL;
}

static char doc_surfit[] = " [tx,ty,c,o] = _surfit(x, y, z, w, xb, xe, yb, ye,"\
      " kx,ky,iopt,s,eps,tx,ty,nxest,nyest,wrk,lwrk1,lwrk2)";
static PyObject *
fitpack_surfit(PyObject *dummy, PyObject *args)
{
    int iopt, m, kx, ky, nxest, nyest, lwrk1, lwrk2, *iwrk, kwrk, ier;
    int lwa, nxo, nyo, i, lcest, nmax, nx, ny, lc;
    npy_intp dims[1];
    double *x, *y, *z, *w, xb, xe, yb, ye, s, *tx, *ty, *c, fp;
    double *wrk1, *wrk2, *wa = NULL, eps;
    PyArrayObject *ap_x = NULL, *ap_y = NULL, *ap_z, *ap_w = NULL;
    PyArrayObject *ap_tx = NULL,*ap_ty = NULL,*ap_c = NULL, *ap_wrk = NULL;
    PyObject *x_py = NULL, *y_py = NULL, *z_py = NULL, *w_py = NULL;
    PyObject *tx_py = NULL, *ty_py = NULL, *wrk_py = NULL;

    nx = ny = ier = nxo = nyo = 0;
    if (!PyArg_ParseTuple(args, "OOOOddddiiiddOOiiOii",
                &x_py, &y_py, &z_py, &w_py, &xb, &xe, &yb, &ye,
                &kx, &ky, &iopt, &s, &eps, &tx_py, &ty_py, &nxest,
                &nyest, &wrk_py, &lwrk1, &lwrk2)) {
        return NULL;
    }
    ap_x = (PyArrayObject *)PyArray_ContiguousFromObject(x_py, NPY_DOUBLE, 0, 1);
    ap_y = (PyArrayObject *)PyArray_ContiguousFromObject(y_py, NPY_DOUBLE, 0, 1);
    ap_z = (PyArrayObject *)PyArray_ContiguousFromObject(z_py, NPY_DOUBLE, 0, 1);
    ap_w = (PyArrayObject *)PyArray_ContiguousFromObject(w_py, NPY_DOUBLE, 0, 1);
    ap_wrk=(PyArrayObject *)PyArray_ContiguousFromObject(wrk_py, NPY_DOUBLE, 0, 1);
    /*ap_iwrk=(PyArrayObject *)PyArray_ContiguousFromObject(iwrk_py, NPY_INT, 0, 1);*/
    if (ap_x == NULL
            || ap_y == NULL
            || ap_z == NULL
            || ap_w == NULL
            || ap_wrk == NULL) {
        goto fail;
    }
    x = (double *) ap_x->data;
    y = (double *) ap_y->data;
    z = (double *) ap_z->data;
    w = (double *) ap_w->data;
    m = ap_x->dimensions[0];
    nmax = nxest;
    if (nmax < nyest) {
        nmax = nyest;
    }
    lcest = (nxest - kx - 1)*(nyest - ky - 1);
    kwrk = m + (nxest - 2*kx - 1)*(nyest - 2*ky - 1);
    lwa = 2*nmax + lcest + lwrk1 + lwrk2 + kwrk;
    if ((wa = (double *)malloc(lwa*sizeof(double))) == NULL) {
        PyErr_NoMemory();
        goto fail;
    }
    tx = wa;
    ty = tx + nmax;
    c = ty + nmax;
    wrk1 = c + lcest;
    iwrk = (int *)(wrk1 + lwrk1);
    wrk2 = (double *)(iwrk + kwrk);
    if (iopt) {
        ap_tx = (PyArrayObject *)PyArray_ContiguousFromObject(tx_py, NPY_DOUBLE, 0, 1);
        ap_ty = (PyArrayObject *)PyArray_ContiguousFromObject(ty_py, NPY_DOUBLE, 0, 1);
        if (ap_tx == NULL || ap_ty == NULL) {
            goto fail;
        }
        nx = nxo = ap_tx->dimensions[0];
        ny = nyo = ap_ty->dimensions[0];
        memcpy(tx,ap_tx->data,nx*sizeof(double));
        memcpy(ty,ap_ty->data,ny*sizeof(double));
    }
    if (iopt==1) {
        lc = (nx - kx - 1)*(ny - ky - 1);
        memcpy(wrk1, ap_wrk->data, lc*sizeof(double));
        /*memcpy(iwrk,ap_iwrk->data,n*sizeof(int));*/
    }
    SURFIT(&iopt, &m, x, y, z, w, &xb, &xe, &yb, &ye, &kx, &ky,
            &s, &nxest, &nyest, &nmax, &eps, &nx, tx, &ny, ty,
            c, &fp, wrk1, &lwrk1, wrk2, &lwrk2, iwrk, &kwrk, &ier);
    i = 0;
    while ((ier > 10) && (i++ < 5)) {
        lwrk2 = ier;
        if ((wrk2 = (double *)malloc(lwrk2*sizeof(double))) == NULL) {
            PyErr_NoMemory();
            goto fail;
        }
        SURFIT(&iopt, &m, x, y, z, w, &xb, &xe, &yb, &ye, &kx, &ky,
                &s, &nxest, &nyest, &nmax, &eps, &nx, tx, &ny, ty,
                c, &fp, wrk1, &lwrk1, wrk2, &lwrk2, iwrk, &kwrk, &ier);
        if (wrk2) {
            free(wrk2);
        }
    }
    if (ier == 10) {
        PyErr_SetString(PyExc_ValueError, "Invalid inputs.");
        goto fail;
    }
    lc = (nx - kx - 1)*(ny - ky - 1);
    Py_XDECREF(ap_tx);
    Py_XDECREF(ap_ty);
    dims[0] = nx;
    ap_tx = (PyArrayObject *)PyArray_SimpleNew(1, dims, NPY_DOUBLE);
    dims[0] = ny;
    ap_ty = (PyArrayObject *)PyArray_SimpleNew(1, dims, NPY_DOUBLE);
    dims[0] = lc;
    ap_c = (PyArrayObject *)PyArray_SimpleNew(1, dims, NPY_DOUBLE);
    if (ap_tx == NULL
            || ap_ty == NULL
            || ap_c == NULL) {
        goto fail;
    }
    if ((iopt == 0)||(nx > nxo)||(ny > nyo)) {
        Py_XDECREF(ap_wrk);
        dims[0] = lc;
        ap_wrk = (PyArrayObject *)PyArray_SimpleNew(1, dims, NPY_DOUBLE);
        if (ap_wrk == NULL) {
            goto fail;
        }
        /*ap_iwrk = (PyArrayObject *)PyArray_SimpleNew(1,&n,NPY_INT);*/
    }
    if (ap_wrk->dimensions[0] < lc) {
        Py_XDECREF(ap_wrk);
        dims[0] = lc;
        ap_wrk = (PyArrayObject *)PyArray_SimpleNew(1, dims, NPY_DOUBLE);
        if (ap_wrk == NULL) {
            goto fail;
        }
    }
    memcpy(ap_tx->data, tx, nx*sizeof(double));
    memcpy(ap_ty->data, ty, ny*sizeof(double));
    memcpy(ap_c->data, c, lc*sizeof(double));
    memcpy(ap_wrk->data, wrk1, lc*sizeof(double));
    /*memcpy(ap_iwrk->data,iwrk,n*sizeof(int));*/
    if (wa) {
        free(wa);
    }
    Py_DECREF(ap_x);
    Py_DECREF(ap_y);
    Py_DECREF(ap_z);
    Py_DECREF(ap_w);
    return Py_BuildValue("NNN{s:N,s:i,s:d}",PyArray_Return(ap_tx),
            PyArray_Return(ap_ty),PyArray_Return(ap_c),
            "wrk",PyArray_Return(ap_wrk),
            "ier",ier,"fp",fp);

fail:
    if (wa) {
        free(wa);
    }
    Py_XDECREF(ap_x);
    Py_XDECREF(ap_y);
    Py_XDECREF(ap_z);
    Py_XDECREF(ap_w);
    Py_XDECREF(ap_tx);
    Py_XDECREF(ap_ty);
    Py_XDECREF(ap_wrk);
    /*Py_XDECREF(ap_iwrk);*/
    if (!PyErr_Occurred()) {
        PyErr_SetString(PyExc_ValueError,
                "An error occurred.");
    }
    return NULL;
}


static char doc_parcur[] = " [t,c,o] = _parcur(x,w,u,ub,ue,k,iopt,ipar,s,t,nest,wrk,iwrk,per)";
static PyObject *
fitpack_parcur(PyObject *dummy, PyObject *args)
{
    int k, iopt, ipar, nest, *iwrk, idim, m, mx, no=0, nc, ier, lwa, lwrk, i, per;
    int n=0,  lc;
    npy_intp dims[1];
    double *x, *w, *u, *c, *t, *wrk, *wa=NULL, ub, ue, fp, s;
    PyObject *x_py = NULL, *u_py = NULL, *w_py = NULL, *t_py = NULL;
    PyObject *wrk_py=NULL, *iwrk_py=NULL;
    PyArrayObject *ap_x = NULL, *ap_u = NULL, *ap_w = NULL, *ap_t = NULL, *ap_c = NULL;
    PyArrayObject *ap_wrk = NULL, *ap_iwrk = NULL;

    if (!PyArg_ParseTuple(args,  "OOOddiiidOiOOi", &x_py, &w_py, &u_py, &ub, &ue,
                &k, &iopt, &ipar, &s, &t_py, &nest, &wrk_py, &iwrk_py, &per)) {
        return NULL;
    }
    ap_x = (PyArrayObject *)PyArray_ContiguousFromObject(x_py, NPY_DOUBLE, 0, 1);
    ap_u = (PyArrayObject *)PyArray_ContiguousFromObject(u_py, NPY_DOUBLE, 0, 1);
    ap_w = (PyArrayObject *)PyArray_ContiguousFromObject(w_py, NPY_DOUBLE, 0, 1);
    ap_wrk=(PyArrayObject *)PyArray_ContiguousFromObject(wrk_py, NPY_DOUBLE, 0, 1);
    ap_iwrk=(PyArrayObject *)PyArray_ContiguousFromObject(iwrk_py, NPY_INT, 0, 1);
    if (ap_x == NULL
            || ap_u == NULL
            || ap_w == NULL
            || ap_wrk == NULL
            || ap_iwrk == NULL) {
        goto fail;
    }
    x = (double *) ap_x->data;
    u = (double *) ap_u->data;
    w = (double *) ap_w->data;
    m = ap_w->dimensions[0];
    mx = ap_x->dimensions[0];
    idim = mx/m;
    if (per) {
        lwrk = m*(k + 1) + nest*(7 + idim + 5*k);
    }
    else {
        lwrk = m*(k + 1) + nest*(6 + idim + 3*k);
    }
    nc = idim*nest;
    lwa = nc + 2*nest + lwrk;
    if ((wa = (double *)malloc(lwa*sizeof(double))) == NULL) {
        PyErr_NoMemory();
        goto fail;
    }
    t = wa;
    c = t + nest;
    wrk = c + nc;
    iwrk = (int *)(wrk + lwrk);
    if (iopt) {
        ap_t=(PyArrayObject *)PyArray_ContiguousFromObject(t_py, NPY_DOUBLE, 0, 1);
        if (ap_t == NULL) {
            goto fail;
        }
        n = no = ap_t->dimensions[0];
        memcpy(t, ap_t->data, n*sizeof(double));
    }
    if (iopt == 1) {
        memcpy(wrk, ap_wrk->data, n*sizeof(double));
        memcpy(iwrk, ap_iwrk->data, n*sizeof(int));
    }
    if (per) {
        CLOCUR(&iopt, &ipar, &idim, &m, u, &mx, x, w, &k, &s, &nest,
                &n, t, &nc, c, &fp, wrk, &lwrk, iwrk, &ier);
    }
    else {
        PARCUR(&iopt, &ipar, &idim, &m, u, &mx, x, w, &ub, &ue, &k,
                &s, &nest, &n, t, &nc, c, &fp, wrk, &lwrk, iwrk, &ier);
    }
    if (ier == 10) {
        goto fail;
    }
    if (ier > 0 && n == 0) {
        n = 1;
    }
    lc = (n - k - 1)*idim;
    dims[0] = n;
    ap_t = (PyArrayObject *)PyArray_SimpleNew(1, dims, NPY_DOUBLE);
    dims[0] = lc;
    ap_c = (PyArrayObject *)PyArray_SimpleNew(1, dims, NPY_DOUBLE);
    if (ap_t == NULL || ap_c == NULL) {
        goto fail;
    }
    if (iopt == 0|| n > no) {
        dims[0] = n;
        ap_wrk = (PyArrayObject *)PyArray_SimpleNew(1, dims, NPY_DOUBLE);
        ap_iwrk = (PyArrayObject *)PyArray_SimpleNew(1, dims, NPY_INT);
        if (ap_wrk == NULL || ap_iwrk == NULL) {
            goto fail;
        }
    }
    memcpy(ap_t->data, t, n*sizeof(double));
    for (i = 0; i < idim; i++)
        memcpy((double *)ap_c->data + i*(n - k - 1), c + i*n, (n - k - 1)*sizeof(double));
    memcpy(ap_wrk->data, wrk, n*sizeof(double));
    memcpy(ap_iwrk->data, iwrk, n*sizeof(int));
    if (wa) {
        free(wa);
    }
    Py_DECREF(ap_x);
    Py_DECREF(ap_w);
    return Py_BuildValue("NN{s:N,s:d,s:d,s:N,s:N,s:i,s:d}", PyArray_Return(ap_t),
            PyArray_Return(ap_c), "u", PyArray_Return(ap_u), "ub", ub, "ue", ue,
            "wrk", PyArray_Return(ap_wrk), "iwrk", PyArray_Return(ap_iwrk),
            "ier", ier, "fp",fp);
fail:
    if (wa) {
        free(wa);
    }
    Py_XDECREF(ap_x);
    Py_XDECREF(ap_u);
    Py_XDECREF(ap_w);
    Py_XDECREF(ap_t);
    Py_XDECREF(ap_wrk);
    Py_XDECREF(ap_iwrk);
    return NULL;
}

static char doc_curfit[] = " [t,c,o] = _curfit(x,y,w,xb,xe,k,iopt,s,t,nest,wrk,iwrk,per)";
static PyObject *
fitpack_curfit(PyObject *dummy, PyObject *args)
{
    int iopt, m, k, nest, lwrk, *iwrk, ier, lwa, no=0, per;
    int n, lc;
    npy_intp dims[1];
    double *x, *y, *w, xb, xe, s, *t, *c, fp, *wrk, *wa = NULL;
    PyArrayObject *ap_x = NULL, *ap_y = NULL, *ap_w = NULL, *ap_t = NULL, *ap_c = NULL;
    PyArrayObject *ap_wrk = NULL, *ap_iwrk = NULL;
    PyObject *x_py = NULL, *y_py = NULL, *w_py = NULL, *t_py = NULL;
    PyObject *wrk_py=NULL, *iwrk_py=NULL;

    if (!PyArg_ParseTuple(args, "OOOddiidOiOOi", &x_py, &y_py, &w_py, &xb, &xe,
                &k, &iopt, &s, &t_py, &nest, &wrk_py, &iwrk_py, &per)) {
        return NULL;
    }
    ap_x = (PyArrayObject *)PyArray_ContiguousFromObject(x_py, NPY_DOUBLE, 0, 1);
    ap_y = (PyArrayObject *)PyArray_ContiguousFromObject(y_py, NPY_DOUBLE, 0, 1);
    ap_w = (PyArrayObject *)PyArray_ContiguousFromObject(w_py, NPY_DOUBLE, 0, 1);
    ap_wrk = (PyArrayObject *)PyArray_ContiguousFromObject(wrk_py, NPY_DOUBLE, 0, 1);
    ap_iwrk = (PyArrayObject *)PyArray_ContiguousFromObject(iwrk_py, NPY_INT, 0, 1);
    if (ap_x == NULL
            || ap_y == NULL
            || ap_w == NULL
            || ap_wrk == NULL
            || ap_iwrk == NULL) {
        goto fail;
    }
    x = (double *) ap_x->data;
    y = (double *) ap_y->data;
    w = (double *) ap_w->data;
    m = ap_x->dimensions[0];
    if (per) {
        lwrk = m*(k + 1) + nest*(8 + 5*k);
    }
    else {
        lwrk = m*(k + 1) + nest*(7 + 3*k);
    }
    lwa = 3*nest + lwrk;
    if ((wa = (double *)malloc(lwa*sizeof(double))) == NULL) {
        PyErr_NoMemory();
        goto fail;
    }
    t = wa;
    c = t + nest;
    wrk = c + nest;
    iwrk = (int *)(wrk + lwrk);
    if (iopt) {
        ap_t = (PyArrayObject *)PyArray_ContiguousFromObject(t_py, NPY_DOUBLE, 0, 1);
        if (ap_t == NULL) {
            goto fail;
        }
        n = no = ap_t->dimensions[0];
        memcpy(t, ap_t->data, n*sizeof(double));
    }
    if (iopt == 1) {
        memcpy(wrk, ap_wrk->data, n*sizeof(double));
        memcpy(iwrk, ap_iwrk->data, n*sizeof(int));
    }
    if (per)
        PERCUR(&iopt, &m, x, y, w, &k, &s, &nest, &n, t, c, &fp, wrk,
                &lwrk, iwrk, &ier);
    else {
        CURFIT(&iopt, &m, x, y, w, &xb, &xe, &k, &s, &nest, &n, t, c,
                &fp, wrk, &lwrk, iwrk, &ier);
    }
    if (ier == 10) {
        PyErr_SetString(PyExc_ValueError, "Invalid inputs.");
        goto fail;
    }
    lc = n - k - 1;
    if (!iopt) {
        dims[0] = n;
        ap_t = (PyArrayObject *)PyArray_SimpleNew(1, dims, NPY_DOUBLE);
        if (ap_t == NULL) {
            goto fail;
        }
    }
    dims[0] = lc;
    ap_c = (PyArrayObject *)PyArray_SimpleNew(1, dims, NPY_DOUBLE);
    if (ap_c == NULL) {
        goto fail;
    }
    if (iopt == 0 || n > no) {
        Py_XDECREF(ap_wrk);
        Py_XDECREF(ap_iwrk);
        dims[0] = n;
        ap_wrk = (PyArrayObject *)PyArray_SimpleNew(1, dims, NPY_DOUBLE);
        ap_iwrk = (PyArrayObject *)PyArray_SimpleNew(1, dims, NPY_INT);
        if (ap_wrk == NULL || ap_iwrk == NULL) {
            goto fail;
        }
    }
    memcpy(ap_t->data, t, n*sizeof(double));
    memcpy(ap_c->data, c, lc*sizeof(double));
    memcpy(ap_wrk->data, wrk, n*sizeof(double));
    memcpy(ap_iwrk->data, iwrk, n*sizeof(int));
    if (wa) {
        free(wa);
    }
    Py_DECREF(ap_x);
    Py_DECREF(ap_y);
    Py_DECREF(ap_w);
    return Py_BuildValue("NN{s:N,s:N,s:i,s:d}", PyArray_Return(ap_t),
            PyArray_Return(ap_c), "wrk", PyArray_Return(ap_wrk),
            "iwrk", PyArray_Return(ap_iwrk), "ier", ier, "fp", fp);

fail:
    if (wa) {
        free(wa);
    }
    Py_XDECREF(ap_x);
    Py_XDECREF(ap_y);
    Py_XDECREF(ap_w);
    Py_XDECREF(ap_t);
    Py_XDECREF(ap_wrk);
    Py_XDECREF(ap_iwrk);
    return NULL;
}

static char doc_spl_[] = " [y,ier] = _spl_(x,nu,t,c,k,e)";
static PyObject *
fitpack_spl_(PyObject *dummy, PyObject *args)
{
    int n, nu, ier, k, m, e=0;
    npy_intp dims[1];
    double *x, *y, *t, *c, *wrk = NULL;
    PyArrayObject *ap_x = NULL, *ap_y = NULL, *ap_t = NULL, *ap_c = NULL;
    PyObject *x_py = NULL, *t_py = NULL, *c_py = NULL;

    if (!PyArg_ParseTuple(args, "OiOOii", &x_py, &nu, &t_py, &c_py, &k, &e)) {
        return NULL;
    }
    ap_x = (PyArrayObject *)PyArray_ContiguousFromObject(x_py, NPY_DOUBLE, 0, 1);
    ap_t = (PyArrayObject *)PyArray_ContiguousFromObject(t_py, NPY_DOUBLE, 0, 1);
    ap_c = (PyArrayObject *)PyArray_ContiguousFromObject(c_py, NPY_DOUBLE, 0, 1);
    if ((ap_x == NULL || ap_t == NULL || ap_c == NULL)) {
        goto fail;
    }
    x = (double *)ap_x->data;
    m = ap_x->dimensions[0];
    t = (double *)ap_t->data;
    c = (double *)ap_c->data;
    n = ap_t->dimensions[0];
    dims[0] = m;
    ap_y = (PyArrayObject *)PyArray_SimpleNew(1,dims,NPY_DOUBLE);
    if (ap_y == NULL) {
        goto fail;
    }
    y = (double *)ap_y->data;
    if ((wrk = (double *)malloc(n*sizeof(double))) == NULL) {
        PyErr_NoMemory();
        goto fail;
    }
    if (nu) {
        SPLDER(t, &n, c, &k, &nu, x, y, &m, &e, wrk, &ier);
    }
    else {
        SPLEV(t, &n, c, &k, x, y, &m, &e, &ier);
    }
    if (wrk) {
        free(wrk);
    }
    Py_DECREF(ap_x);
    Py_DECREF(ap_c);
    Py_DECREF(ap_t);
    return Py_BuildValue("Ni", PyArray_Return(ap_y), ier);

fail:
    if (wrk) {
        free(wrk);
    }
    Py_XDECREF(ap_x);
    Py_XDECREF(ap_c);
    Py_XDECREF(ap_t);
    return NULL;
}

static char doc_splint[] = " [aint,wrk] = _splint(t,c,k,a,b)";
static PyObject *
fitpack_splint(PyObject *dummy, PyObject *args)
{
    int k, n;
    npy_intp dims[1];
    double *t, *c, *wrk = NULL, a, b, aint;
    PyArrayObject *ap_t = NULL, *ap_c = NULL;
    PyArrayObject *ap_wrk = NULL;
    PyObject *t_py = NULL, *c_py = NULL;

    if (!PyArg_ParseTuple(args, "OOidd",&t_py,&c_py,&k,&a,&b)) {
        return NULL;
    }
    ap_t = (PyArrayObject *)PyArray_ContiguousFromObject(t_py, NPY_DOUBLE, 0, 1);
    ap_c = (PyArrayObject *)PyArray_ContiguousFromObject(c_py, NPY_DOUBLE, 0, 1);
    if ((ap_t == NULL || ap_c == NULL)) {
        goto fail;
    }
    t = (double *)ap_t->data;
    c = (double *)ap_c->data;
    n = ap_t->dimensions[0];
    dims[0] = n;
    ap_wrk = (PyArrayObject *)PyArray_SimpleNew(1, dims, NPY_DOUBLE);
    if (ap_wrk == NULL) {
        goto fail;
    }
    wrk = (double *)ap_wrk->data;
    aint = SPLINT(t,&n,c,&k,&a,&b,wrk);
    Py_DECREF(ap_c);
    Py_DECREF(ap_t);
    return Py_BuildValue("dN", aint, PyArray_Return(ap_wrk));

fail:
    Py_XDECREF(ap_c);
    Py_XDECREF(ap_t);
    return NULL;
}

static char doc_sproot[] = " [z,ier] = _sproot(t,c,k,mest)";
static PyObject *
fitpack_sproot(PyObject *dummy, PyObject *args)
{
    int n, k, m, mest, ier;
    npy_intp dims[1];
    double *t, *c, *z = NULL;
    PyArrayObject *ap_t = NULL, *ap_c = NULL;
    PyArrayObject *ap_z = NULL;
    PyObject *t_py = NULL, *c_py = NULL;

    if (!PyArg_ParseTuple(args, "OOii",&t_py,&c_py,&k,&mest)) {
        return NULL;
    }
    ap_t = (PyArrayObject *)PyArray_ContiguousFromObject(t_py, NPY_DOUBLE, 0, 1);
    ap_c = (PyArrayObject *)PyArray_ContiguousFromObject(c_py, NPY_DOUBLE, 0, 1);
    if ((ap_t == NULL || ap_c == NULL)) {
        goto fail;
    }
    t = (double *)ap_t->data;
    c = (double *)ap_c->data;
    n = ap_t->dimensions[0];
    if ((z = (double *)malloc(mest*sizeof(double))) == NULL) {
        PyErr_NoMemory();
        goto fail;
    }
    m = 0;
    SPROOT(t,&n,c,z,&mest,&m,&ier);
    if (ier==10) {
        m = 0;
    }
    dims[0] = m;
    ap_z = (PyArrayObject *)PyArray_SimpleNew(1, dims, NPY_DOUBLE);
    if (ap_z == NULL) {
        goto fail;
    }
    memcpy(ap_z->data,z,m*sizeof(double));
    if (z) {
        free(z);
    }
    Py_DECREF(ap_c);
    Py_DECREF(ap_t);
    return Py_BuildValue("Ni", PyArray_Return(ap_z), ier);

fail:
    if (z) {
        free(z);
    }
    Py_XDECREF(ap_c);
    Py_XDECREF(ap_t);
    return NULL;
}

static char doc_spalde[] = " [d,ier] = _spalde(t,c,k,x)";
static PyObject *
fitpack_spalde(PyObject *dummy, PyObject *args)
{
    int n, k, ier, k1;
    npy_intp dims[1];
    double *t, *c, *d = NULL, x;
    PyArrayObject *ap_t = NULL, *ap_c = NULL, *ap_d = NULL;
    PyObject *t_py = NULL, *c_py = NULL;

    if (!PyArg_ParseTuple(args, "OOid",&t_py,&c_py,&k,&x)) {
        return NULL;
    }
    ap_t = (PyArrayObject *)PyArray_ContiguousFromObject(t_py, NPY_DOUBLE, 0, 1);
    ap_c = (PyArrayObject *)PyArray_ContiguousFromObject(c_py, NPY_DOUBLE, 0, 1);
    if ((ap_t == NULL || ap_c == NULL)) {
        goto fail;
    }
    t = (double *)ap_t->data;
    c = (double *)ap_c->data;
    n = ap_t->dimensions[0];
    k1 = k + 1;
    dims[0] = k1;
    ap_d = (PyArrayObject *)PyArray_SimpleNew(1, dims, NPY_DOUBLE);
    if (ap_d == NULL) {
        goto fail;
    }
    d = (double *)ap_d->data;
    SPALDE(t, &n, c, &k1, &x, d, &ier);
    Py_DECREF(ap_c);
    Py_DECREF(ap_t);
    return Py_BuildValue("Ni", PyArray_Return(ap_d), ier);

fail:
    Py_XDECREF(ap_c);
    Py_XDECREF(ap_t);
    return NULL;
}

static char doc_insert[] = " [tt,cc,ier] = _insert(iopt,t,c,k,x,m)";
static PyObject *
fitpack_insert(PyObject *dummy, PyObject*args)
{
    int iopt, n, nn, k, ier, m, nest;
    npy_intp dims[1];
    double x;
    double *t, *c, *tt, *cc;
    PyArrayObject *ap_t = NULL, *ap_c = NULL, *ap_tt = NULL, *ap_cc = NULL;
    PyObject *t_py = NULL, *c_py = NULL;
    PyObject *ret = NULL;

    if (!PyArg_ParseTuple(args, "iOOidi",&iopt,&t_py,&c_py,&k, &x, &m)) {
        return NULL;
    }
    ap_t = (PyArrayObject *)PyArray_ContiguousFromObject(t_py, NPY_DOUBLE, 0, 1);
    ap_c = (PyArrayObject *)PyArray_ContiguousFromObject(c_py, NPY_DOUBLE, 0, 1);
    if (ap_t == NULL || ap_c == NULL) {
        goto fail;
    }
    t = (double *)ap_t->data;
    c = (double *)ap_c->data;
    n = ap_t->dimensions[0];
    nest = n + m;
    dims[0] = nest;
    ap_tt = (PyArrayObject *)PyArray_SimpleNew(1, dims, NPY_DOUBLE);
    ap_cc = (PyArrayObject *)PyArray_SimpleNew(1, dims, NPY_DOUBLE);
    if (ap_tt == NULL || ap_cc == NULL) {
        goto fail;
    }
    tt = (double *)ap_tt->data;
    cc = (double *)ap_cc->data;
    for ( ; n < nest; n++) {
        INSERT(&iopt, t, &n, c, &k, &x, tt, &nn, cc, &nest, &ier);
        if (ier) {
            break;
        }
        t = tt;
        c = cc;
    }
    Py_DECREF(ap_c);
    Py_DECREF(ap_t);
    ret = Py_BuildValue("NNi", PyArray_Return(ap_tt), PyArray_Return(ap_cc), ier);
    return ret;

fail:
    Py_XDECREF(ap_c);
    Py_XDECREF(ap_t);
    return NULL;
}


static void
_deBoor_D(double *t, double x, int k, int ell, int m, double *result) {
    /*
     * On completion the result array stores
     * the k+1 non-zero values of beta^(m)_i,k(x):  for i=ell, ell-1, ell-2, ell-k.
     * Where t[ell] <= x < t[ell+1].
     */
    /*
     * Implements a recursive algorithm similar to the original algorithm of
     * deBoor.
     */
    double *hh = result + k + 1;
    double *h = result;
    double xb, xa, w;
    int ind, j, n;

    /*
     * Perform k-m "standard" deBoor iterations
     * so that h contains the k+1 non-zero values of beta_{ell,k-m}(x)
     * needed to calculate the remaining derivatives.
     */
    result[0] = 1.0;
    for (j = 1; j <= k - m; j++) {
        memcpy(hh, h, j*sizeof(double));
        h[0] = 0.0;
        for (n = 1; n <= j; n++) {
            ind = ell + n;
            xb = t[ind];
            xa = t[ind - j];
            if (xb == xa) {
                h[n] = 0.0;
                continue;
            }
            w = hh[n - 1]/(xb - xa);
            h[n - 1] += w*(xb - x);
            h[n] = w*(x - xa);
        }
    }

    /*
     * Now do m "derivative" recursions
     * to convert the values of beta into the mth derivative
     */
    for (j = k - m + 1; j <= k; j++) {
        memcpy(hh, h, j*sizeof(double));
        h[0] = 0.0;
        for (n = 1; n <= j; n++) {
            ind = ell + n;
            xb = t[ind];
            xa = t[ind - j];
            if (xb == xa) {
                h[m] = 0.0;
                continue;
            }
            w = j*hh[n - 1]/(xb - xa);
            h[n - 1] -= w;
            h[n] = w;
        }
    }
}


/*
 * Given a set of (N+1) samples:  A default set of knots is constructed
 * using the samples xk plus 2*(K-1) additional knots where
 * K = max(order,1) and the knots are chosen so that distances
 * are symmetric around the first and last samples: x_0 and x_N.
 *
 * There should be a vector of N+K coefficients for the spline
 * curve in coef.  These coefficients form the curve as
 *
 * s(x) = sum(c_j B_{j,K}(x), j=-K..N-1)
 *
 * The spline function is evaluated at all points xx.
 * The approximation interval is from xk[0] to xk[-1]
 * Any xx outside that interval is set automatically to 0.0
 */
static char doc_bspleval[] = "y = _bspleval(xx,xk,coef,k,{deriv (0)})\n"
"\n"
"The spline is defined by the approximation interval xk[0] to xk[-1],\n"
"the length of xk (N+1), the order of the spline, k, and \n"
"the number of coeficients N+k.  The coefficients range from xk_{-K}\n"
"to xk_{N-1} inclusive and are all the coefficients needed to define\n"
"an arbitrary spline of order k, on the given approximation interval\n"
"\n"
"Extra knot points are internally added using knot-point symmetry \n"
"around xk[0] and xk[-1]";

static PyObject *
_bspleval(PyObject *dummy, PyObject *args)
{
    int k, kk, N, i, ell, dk, deriv = 0;
    PyObject *xx_py = NULL, *coef_py = NULL, *x_i_py = NULL;
    PyArrayObject *xx = NULL, *coef = NULL, *x_i = NULL, *yy = NULL;
    PyArrayIterObject *xx_iter;
    double *t = NULL, *h = NULL, *ptr;
    double x0, xN, xN1, arg, sp, cval;

    if (!PyArg_ParseTuple(args, "OOOi|i", &xx_py, &x_i_py, &coef_py, &k, &deriv)) {
        return NULL;
    }
    if (k < 0) {
        PyErr_Format(PyExc_ValueError,
                "order (%d) must be >=0", k);
        return NULL;
    }
    if (deriv > k) {
        PyErr_Format(PyExc_ValueError,
                "derivative (%d) must be <= order (%d)", deriv, k);
        return NULL;
    }
    kk = k;
    if (k == 0) {
        kk = 1;
    }
    dk = (k == 0 ? 0 : 1);
    x_i = (PyArrayObject *)PyArray_FROMANY(x_i_py, NPY_DOUBLE, 1, 1, NPY_ALIGNED);
    coef = (PyArrayObject *)PyArray_FROMANY(coef_py, NPY_DOUBLE, 1, 1, NPY_ALIGNED);
    xx = (PyArrayObject *)PyArray_FROMANY(xx_py, NPY_DOUBLE, 0, 0, NPY_ALIGNED);
    if (x_i == NULL || coef == NULL || xx == NULL) {
        goto fail;
    }

    N = PyArray_DIM(x_i, 0) - 1;
    if (PyArray_DIM(coef, 0) < N + k) {
        PyErr_Format(PyExc_ValueError,
                "too few coefficients (have %d need at least %d)",
                (int)PyArray_DIM(coef, 0), N + k);
        goto fail;
    }

    /* create output values */
    yy = (PyArrayObject *)PyArray_EMPTY(xx->nd, xx->dimensions, NPY_DOUBLE, 0);
    if (yy == NULL) {
        goto fail;
    }
    /*
     * create dummy knot array with new knots inserted at the end
     * selected as mirror symmetric versions of the old knots
     */
    t = (double *)malloc(sizeof(double)*(N + 2*kk - 1));
    if (t == NULL) {
        PyErr_NoMemory();
        goto fail;
    }
    x0 = *((double *)PyArray_DATA(x_i));
    xN = *((double *)PyArray_DATA(x_i) + N);
    for (i = 0; i < kk - 1; i++) { /* fill in ends if kk > 1*/
        t[i] = 2*x0 - *((double *)(PyArray_GETPTR1(x_i, kk - 1 - i)));
        t[kk+N+i] = 2*xN - *((double *)(PyArray_GETPTR1(x_i, N - 1 - i)));
    }
    ptr = t + (kk - 1);
    for (i = 0; i <= N; i++) {
        *ptr++ = *((double *)(PyArray_GETPTR1(x_i, i)));
    }

    /*
     * Create work array to hold computed non-zero values for
     * the spline for a value of x.
     */
    h = (double *)malloc(sizeof(double)*(2*kk+1));
    if (h == NULL) {
        PyErr_NoMemory();
        goto fail;
    }

    /* Determine the spline for each value of x */
    xx_iter = (PyArrayIterObject *)PyArray_IterNew((PyObject *)xx);
    if (xx_iter == NULL) {
        goto fail;
    }
    ptr = PyArray_DATA(yy);

    while(PyArray_ITER_NOTDONE(xx_iter)) {
        arg = *((double *)PyArray_ITER_DATA(xx_iter));
        if ((arg < x0) || (arg > xN)) {
            /*
             * If we are outside the interpolation region,
             * fill with zeros
             */
            *ptr++ = 0.0;
        }
        else {
            /*
             * Find the interval that arg lies between in the set of knots
             * t[ell] <= arg < t[ell+1] (last-knot use the previous interval)
             */
            xN1 = *((double *)PyArray_DATA(x_i) + N-1);
            if (arg >= xN1) {
                ell = N + kk - 2;
            }
            else {
                ell = kk - 1;
                while ((arg > t[ell])) {
                    ell++;
                }
                if (arg != t[ell]) {
                    ell--;
                }
            }

            _deBoor_D(t, arg, k, ell, deriv, h);

            sp = 0.0;
            for (i = 0; i <= k; i++) {
                cval = *((double *)(PyArray_GETPTR1(coef, ell - i + dk)));
                sp += cval * h[k - i];
            }
            *ptr++ = sp;
        }
        PyArray_ITER_NEXT(xx_iter);
    }
    Py_DECREF(xx_iter);
    Py_DECREF(x_i);
    Py_DECREF(coef);
    Py_DECREF(xx);
    free(t);
    free(h);
    return PyArray_Return(yy);

fail:
    Py_XDECREF(xx);
    Py_XDECREF(coef);
    Py_XDECREF(x_i);
    Py_XDECREF(yy);
    if (t != NULL) {
        free(t);
    }
    if (h != NULL) {
        free(h);
    }
    return NULL;
}


/*
 * Given a set of (N+1) sample positions:
 * Construct the diagonals of the (N+1) x (N+K) matrix that is needed to find
 * the coefficients of a spline fit of order K.
 * Note that K>=2 because for K=0,1, the coefficients are just the
 * sample values themselves.
 *
 * The equation that expresses the constraints is
 *
 * s(x_i) = sum(c_j B_{j,K}(x_i), j=-K..N-1) = w_i   for i=0..N
 *
 * This is equivalent to
 *
 * w = B*c   where c.T = [c_{-K}, c{-K+1}, ..., c_{N-1}] and
 * w.T = [w_{0}, w_{1}, ..., w_{N}]
 *
 * Therefore B is an (N+1) times (N+K) matrix with entries
 *
 * B_{j,K}(x_i)  for column j=-K..N-1
 * and row i=0..N
 *
 * This routine takes the N+1 sample positions and the order k and
 * constructs the banded constraint matrix B (with k non-zero diagonals)
 *
 * The returned array is (N+1) times (N+K) ready to be either used
 * to compute a minimally Kth-order derivative discontinuous spline
 * or to be expanded with an additional K-1 constraints to be used in
 * an exact spline specification.
 */
static char doc_bsplmat[] = "B = _bsplmat(order,xk)\n"
"Construct the constraint matrix for spline fitting of order k\n"
"given sample positions in xk.\n"
"\n"
"If xk is an integer (N+1), then the result is equivalent to\n"
"xk=arange(N+1)+x0 for any value of x0.   This produces the\n"
"integer-spaced, or cardinal spline matrix a bit faster.";
static PyObject *
_bsplmat(PyObject *dummy, PyObject *args) {
    int k, N, i, numbytes, j, equal;
    npy_intp dims[2];
    PyObject *x_i_py = NULL;
    PyArrayObject *x_i = NULL, *BB = NULL;
    double *t = NULL, *h = NULL, *ptr;
    double x0, xN, arg;

    if (!PyArg_ParseTuple(args, "iO", &k, &x_i_py)) {
        return NULL;
    }
    if (k < 2) {
        PyErr_Format(PyExc_ValueError, "order (%d) must be >=2", k);
        return NULL;
    }

    equal = 0;
    N = PySequence_Length(x_i_py);
    if (N == -1 && PyErr_Occurred()) {
        PyErr_Clear();
        N = PyInt_AsLong(x_i_py);
        if (N == -1 && PyErr_Occurred()) {
            goto fail;
        }
        equal = 1;
    }
    N -= 1;

    /* create output matrix */
    dims[0] = N + 1;
    dims[1] = N + k;
    BB = (PyArrayObject *)PyArray_ZEROS(2, dims, NPY_DOUBLE, 0);
    if (BB == NULL) {
        goto fail;
    }

    t = (double *)malloc(sizeof(double)*(N + 2*k - 1));
    if (t == NULL) {
        PyErr_NoMemory();
        goto fail;
    }

    /*
     * Create work array to hold computed non-zero values for
     * the spline for a value of x.
     */
    h = (double *)malloc(sizeof(double)*(2*k + 1));
    if (h == NULL) {
        PyErr_NoMemory();
        goto fail;
    }

    numbytes = k*sizeof(double);

    if (equal) {
        /*
         * points equally spaced by 1
         * we run deBoor's algorithm one time with artificially created knots
         * Then, we keep copying the result to every row
         */

        /* Create knots at equally-spaced locations from -(K-1) to N+K-1 */
        ptr = t;
        for (i = -k + 1; i < N + k; i++) {
            *ptr++ = i;
        }
        j = k - 1;
        _deBoor_D(t, 0, k, k-1, 0, h);
        ptr = PyArray_DATA(BB);
        N = N+1;
        for (i = 0; i < N; i++) {
            memcpy(ptr, h, numbytes);
            ptr += N + k;
        }
        goto finish;
    }

    /* Not-equally spaced */
    x_i = (PyArrayObject *)PyArray_FROMANY(x_i_py, NPY_DOUBLE, 1, 1, NPY_ALIGNED);
    if (x_i == NULL) {
        return NULL;
    }
    /*
     * create dummy knot array with new knots inserted at the end
     * selected as mirror symmetric versions of the old knots
     */
    x0 = *((double *)PyArray_DATA(x_i));
    xN = *((double *)PyArray_DATA(x_i) + N);
    for (i = 0; i < k - 1; i++) {
        /* fill in ends if k > 1*/
        t[i] = 2*x0 - *((double *)(PyArray_GETPTR1(x_i, k - 1 - i)));
        t[k+N+i] = 2*xN - *((double *)(PyArray_GETPTR1(x_i, N - 1 - i)));
    }
    ptr = t + (k - 1);
    for (i = 0; i <= N; i++) {
        *ptr++ = *((double *)(PyArray_GETPTR1(x_i, i)));
    }


    /*
     * Determine the K+1 non-zero values of the spline and place them in the
     * correct location in the matrix for each row (along the diagonals).
     * In fact, the last member is always zero so only K non-zero values
     * are present.
     */
    ptr = PyArray_DATA(BB);
    for (i = 0, j = k - 1; i < N; i++, j++) {
        arg = *((double *)PyArray_DATA(x_i) + i);
        _deBoor_D(t, arg, k, j, 0, h);
        memcpy(ptr, h, numbytes);
        /* advance to next row shifted over one */
        ptr += (N + k + 1);
    }
    /* Last row is different the first coefficient is zero.*/
    _deBoor_D(t, xN, k, j - 1, 0, h);
    memcpy(ptr, h + 1, numbytes);

finish:
    Py_XDECREF(x_i);
    free(t);
    free(h);
    return (PyObject *)BB;

fail:
    Py_XDECREF(x_i);
    Py_XDECREF(BB);
    if (t != NULL) {
        free(t);
    }
    if (h != NULL) {
        free(h);
    }
    return NULL;
}



/*
 * Given a set of (N+1) sample positions:
 * Construct the (N-1) x (N+K) error matrix J_{ij} such that
 *
 * for i=1..N-1,
 *
 * e_i = sum(J_{ij}c_{j},j=-K..N-1)
 *
 * is the discontinuity of the Kth derivative at the point i in the spline.
 *
 * This routine takes the N+1 sample positions and the order k and
 * constructs the banded matrix J
 *
 * The returned array is (N+1) times (N+K) ready to be either used
 * to compute a minimally Kth-order derivative discontinuous spline
 * or to be expanded with an additional K-1 constraints to be used in
 * an exact reconstruction approach.
 */
static char doc_bspldismat[] = "B = _bspldismat(order,xk)\n"
"Construct the kth derivative discontinuity jump constraint matrix \n"
"for spline fitting of order k given sample positions in xk.\n"
"\n"
"If xk is an integer (N+1), then the result is equivalent to\n"
"xk=arange(N+1)+x0 for any value of x0.   This produces the\n"
"integer-spaced matrix a bit faster.  If xk is a 2-tuple (N+1,dx)\n"
"then it produces the result as if the sample distance were dx";
static PyObject *
_bspldismat(PyObject *dummy, PyObject *args)
{
    int k, N, i, j, equal, m;
    npy_intp dims[2];
    PyObject *x_i_py = NULL;
    PyArrayObject *x_i = NULL, *BB = NULL;
    double *t = NULL, *h = NULL, *ptr, *dptr;
    double x0, xN, dx;

    if (!PyArg_ParseTuple(args, "iO", &k, &x_i_py)) {
        return NULL;
    }
    if (k < 2) {
        PyErr_Format(PyExc_ValueError, "order (%d) must be >=2", k);
        return NULL;
    }

    equal = 0;
    N = PySequence_Length(x_i_py);
    if (N == 2 || (N == -1 && PyErr_Occurred())) {
        PyErr_Clear();
        if (PyTuple_Check(x_i_py)) {
            /* x_i_py = (N+1, dx) */
            N = PyInt_AsLong(PyTuple_GET_ITEM(x_i_py, 0));
            dx = PyFloat_AsDouble(PyTuple_GET_ITEM(x_i_py, 1));
        }
        else {
            N = PyInt_AsLong(x_i_py);
            if (N == -1 && PyErr_Occurred()) {
                goto fail;
            }
            dx = 1.0;
        }
        equal = 1;
    }
    N -= 1;

    if (N < 2) {
        PyErr_Format(PyExc_ValueError, "too few samples (%d)", N);
        return NULL;
    }
    /* create output matrix */
    dims[0] = N - 1;
    dims[1] = N + k;
    BB = (PyArrayObject *)PyArray_ZEROS(2, dims, NPY_DOUBLE, 0);
    if (BB == NULL) {
        goto fail;
    }
    t = (double *)malloc(sizeof(double)*(N+2*k-1));
    if (t == NULL) {
        PyErr_NoMemory();
        goto fail;
    }

    /*
     * Create work array to hold computed non-zero values for
     * the spline for a value of x.
     */
    h = (double *)malloc(sizeof(double)*(2*k + 1));
    if (h == NULL) {
        PyErr_NoMemory();
        goto fail;
    }

    if (equal) {
        /*
         * points equally spaced by 1
         * we run deBoor's full derivative algorithm twice, subtract the results
         * offset by one and then copy the result one time with artificially created knots
         * Then, we keep copying the result to every row
         */

        /* Create knots at equally-spaced locations from -(K-1) to N+K-1 */
        double *tmp, factor;
        int numbytes;
        numbytes = (k + 2)*sizeof(double);
        tmp = malloc(numbytes);
        if (tmp == NULL) {
            PyErr_NoMemory();
            goto fail;
        }
        ptr = t;
        for (i = -k + 1; i < N + k; i++) {
            *ptr++ = i;
        }
        j = k - 1;
        _deBoor_D(t, 0, k, k-1, k, h);
        ptr = tmp;
        for (m = 0; m <= k; m++) {
            *ptr++ = -h[m];
        }
        _deBoor_D(t, 0, k, k, k, h);
        ptr = tmp + 1;
        for (m = 0; m <= k; m++) {
            *ptr++ += h[m];
        }
        if (dx != 1.0) {
            factor = pow(dx, (double)k);
            for (m = 0; m < k + 2; m++) {
                tmp[m] /= factor;
            }
        }
        ptr = PyArray_DATA(BB);
        for (i = 0; i < N - 1; i++) {
            memcpy(ptr, tmp, numbytes);
            ptr += N + k + 1;
        }
        free(tmp);
        goto finish;
    }

    /* Not-equally spaced */
    x_i = (PyArrayObject *)PyArray_FROMANY(x_i_py, NPY_DOUBLE, 1, 1, NPY_ALIGNED);
    if (x_i == NULL) {
        return NULL;
    }
    /*
     * create dummy knot array with new knots inserted at the end
     * selected as mirror symmetric versions of the old knots
     */
    x0 = *((double *)PyArray_DATA(x_i));
    xN = *((double *)PyArray_DATA(x_i) + N);
    for (i = 0; i < k - 1; i++) {
        /* fill in ends if k > 1*/
        t[i] = 2*x0 - *((double *)(PyArray_GETPTR1(x_i, k - 1 - i)));
        t[k+N+i] = 2*xN - *((double *)(PyArray_GETPTR1(x_i, N - 1 - i)));
    }
    ptr = t + (k - 1);
    for (i = 0; i <= N; i++) {
        *ptr++ = *((double *)(PyArray_GETPTR1(x_i, i)));
    }


    /*
     * Determine the K+1 non-zero values of the discontinuity jump matrix
     * and place them in the correct location in the matrix for each row
     * (along the diagonals).
     *
     * The matrix is
     *
     * J_{ij} = b^{(k)}_{j,k}(x^{+}_i) - b^{(k)}_{j,k}(x^{-}_i)
     */
    ptr = PyArray_DATA(BB);
    dptr = ptr;
    for (i = 0, j = k - 1; i < N - 1; i++, j++) {
        _deBoor_D(t, 0, k, j, k, h);
        /* We need to copy over but negate the terms */
        for (m = 0; m <= k; m++) {
            *ptr++ = -h[m];
        }
        /*
         * If we are past the first row, then we need to also add the current
         * values result to the previous row
         */
        if (i > 0) {
            for (m = 0; m <= k; m++) {
                *dptr++ += h[m];
            }
        }
        /* store location of last start position plus one.*/
        dptr = ptr - k;
        /* advance to next row shifted over one */
        ptr += N;
    }
    /* We need to finish the result for the last row. */
    _deBoor_D(t, 0, k, j, k, h);
    for (m = 0; m <= k; m++) {
        *dptr++ += h[m];
    }

finish:
    Py_XDECREF(x_i);
    free(t);
    free(h);
    return (PyObject *)BB;

fail:
    Py_XDECREF(x_i);
    Py_XDECREF(BB);
    if (t != NULL) {
        free(t);
    }
    if (h != NULL) {
        free(h);
    }
    return NULL;
}
