/**********
Copyright 1992 Regents of the University of California.  All rights
reserved.
Author: 1992 Charles Hough
Modified: 2004 Paolo Nenzi - (ng)spice integration
**********/


#include "ngspice/ngspice.h"
#include "ngspice/smpdefs.h"
#include "cpldefs.h"
#include "ngspice/sperror.h"
#include "ngspice/suffix.h"

#include "ngspice/multi_line.h"



#define VECTOR_ALLOC(vec, type, n) {            \
        vec = TMALLOC(type *, n);               \
}

#define MATRIX_ALLOC(mat, type, m, j) {         \
        int k;                                  \
        mat = TMALLOC(type **, m);              \
        for (k = 0; k < m; k++) {               \
            VECTOR_ALLOC(mat[k], type, j);      \
        }                                       \
}

#define VECTOR_FREE(vec) free(vec)

#define MATRIX_FREE(mat, m, j) {                \
        int k;                                  \
        for (k = 0; k < m; k++) {               \
            free(mat[k]);                       \
        }                                       \
        free(mat);                              \
}

#define MAX_DEG 8
#define epsilon 1.0e-88
#define MAX_STRING 128

static  double  ZY[MAX_DIM][MAX_DIM];
static  double  Sv[MAX_DIM][MAX_DIM];
static  double  D[MAX_DIM];
static  double  Y5[MAX_DIM][MAX_DIM];
static  double  Y5_1[MAX_DIM][MAX_DIM];
static  double  Sv_1[MAX_DIM][MAX_DIM];

static  double R_m[MAX_DIM][MAX_DIM];
static  double G_m[MAX_DIM][MAX_DIM];
static  double L_m[MAX_DIM][MAX_DIM];
static  double C_m[MAX_DIM][MAX_DIM];
static  double length;
static  double TAU[MAX_DIM];

static  double  A[MAX_DIM][2*MAX_DIM];

static  double  frequency[MAX_DEG];

static  double Si[MAX_DIM][MAX_DIM];
static  double Si_1[MAX_DIM][MAX_DIM];

/*  MacLaurin Series  */
static  double *SiSv_1[MAX_DIM][MAX_DIM];
static  double *Sip[MAX_DIM][MAX_DIM];
static  double *Si_1p[MAX_DIM][MAX_DIM];
static  double *Sv_1p[MAX_DIM][MAX_DIM];
static  double *W[MAX_DIM];

static  Mult_Out IWI[MAX_DIM][MAX_DIM];
static  Mult_Out IWV[MAX_DIM][MAX_DIM];
static  Single_Out SIV[MAX_DIM][MAX_DIM];
static  double  At[4][4];
static  double  Scaling_F;
static  double  Scaling_F2;

/* misc.c match */
static void new_memory(int, int, int);
static double *vector(int, int);
static void free_vector(double*, int, int);
static void polint(double*, double*, int, double, double*, double*);
static int match(int, double*, double*, double*);
/* static int match_x(int, double*, double*, double*); */
static int Gaussian_Elimination2(int, int);
static void eval_Si_Si_1(int, double);
static void loop_ZY(int, double);
static void poly_matrix(double *A[MAX_DIM][MAX_DIM], int dim, int deg);
/* static int checkW(double*, double); */
static void poly_W(int, int);
static void eval_frequency(int, int);
static void store(int, int);
static void store_SiSv_1(int, int);
/*static int check(); quale è il prototipo ?*/
static int coupled(int);
static int generate_out(int, int);
static int ReadCpL(CPLinstance*, CKTcircuit*);
/* static int divC(double, double, double, double, double*, double*); */

/* mult */
static void mult_p(double*, double*, double*, int, int, int);
static void matrix_p_mult(double  *A[MAX_DIM][MAX_DIM],
                          double  *D[MAX_DIM],
                          double  *B[MAX_DIM][MAX_DIM],
                          int     dim, int deg, int deg_o,
                          Mult_Out  X[MAX_DIM][MAX_DIM]);
static double approx_mode(double*, double*, double);
static double eval2(double, double, double, double);
static int get_c(double, double, double, double, double, double, double, double*, double*);
static int Pade_apx(double, double*, double*, double*, double*, double*, double*, double*);
static int Gaussian_Elimination(int);
static double root3(double, double, double, double);
static int div3(double, double, double, double, double*, double*);
static int find_roots(double, double, double, double*, double*, double*);

static NODE* insert_node(char*);
static NDnamePt insert_ND(char*, NDnamePt*);
static NODE* NEW_node(void);
static NDnamePt ndn_btree;
static NODE *node_tab;
#define epsi_mult 1e-28

/* diag */
static MAXE_PTR sort(MAXE_PTR, double, int, int, MAXE_PTR);
static void ordering(void);
static MAXE_PTR delete_1(MAXE_PTR*, int);
static void reordering(int, int);
static void diag(int);
static int rotate(int, int, int);

#define epsi 1.0e-16
static char *message = "tau of coupled lines is larger than max time step";

/* ARGSUSED */
int
CPLsetup(SMPmatrix *matrix, GENmodel *inModel, CKTcircuit *ckt, int *state)
{
    CPLmodel *model = (CPLmodel *)inModel;
    CPLinstance *here;
    CKTnode *tmp, *node;
    int error, m, p;
    char **branchname;
    int noL;

    NG_IGNORE(state);

    /*  loop through all the models */
    for( ; model != NULL; model = model->CPLnextModel ) {

        if (!model->Rmgiven) {
            SPfrontEnd->IFerrorf (ERR_FATAL,
                                 "model %s: lossy line series resistance not given", model->CPLmodName);
            return(E_BADPARM);
        }
        if (!model->Gmgiven) {
            SPfrontEnd->IFerrorf (ERR_FATAL,
                                 "model %s: lossy line parallel conductance not given", model->CPLmodName);
            return(E_BADPARM);
        }
        if (!model->Lmgiven) {
            SPfrontEnd->IFerrorf (ERR_FATAL,
                                 "model %s: lossy line series inductance not given", model->CPLmodName);
            return (E_BADPARM);
        }
        if (!model->Cmgiven) {
            SPfrontEnd->IFerrorf (ERR_FATAL,
                                 "model %s: lossy line parallel capacitance not given", model->CPLmodName);
            return (E_BADPARM);
        }
        if (!model->lengthgiven) {
            SPfrontEnd->IFerrorf (ERR_FATAL,
                                 "model %s: lossy line length must be given", model->CPLmodName);
            return (E_BADPARM);
        }

        /* loop through all the instances of the model */
        for (here = model->CPLinstances; here != NULL ;
                here=here->CPLnextInstance) {

            if (!here->CPLlengthGiven)
                here->CPLlength=0.0;

            /* macro to make elements with built in test for out of memory */
#define TSTALLOC(ptr,first,second) \
do { if((here->ptr = SMPmakeElt(matrix, here->first, here->second)) == NULL){\
    return(E_NOMEM);\
} } while(0)

            noL = here->dimension;

            here->CPLposNodes = TMALLOC(int, noL);
            here->CPLnegNodes = TMALLOC(int, noL);
            here->CPLibr1 = TMALLOC(int, noL);
            here->CPLibr2 = TMALLOC(int, noL);

            VECTOR_ALLOC(here->CPLibr1Ibr1Ptr, double, noL);
            VECTOR_ALLOC(here->CPLibr2Ibr2Ptr, double, noL);
            VECTOR_ALLOC(here->CPLposIbr1Ptr, double, noL);
            VECTOR_ALLOC(here->CPLnegIbr2Ptr, double, noL);
            VECTOR_ALLOC(here->CPLposPosPtr, double, noL);
            VECTOR_ALLOC(here->CPLnegNegPtr, double, noL);
            VECTOR_ALLOC(here->CPLnegPosPtr, double, noL);
            VECTOR_ALLOC(here->CPLposNegPtr, double, noL);

            MATRIX_ALLOC(here->CPLibr1PosPtr, double, noL, noL);
            MATRIX_ALLOC(here->CPLibr2NegPtr, double, noL, noL);
            MATRIX_ALLOC(here->CPLibr1NegPtr, double, noL, noL);
            MATRIX_ALLOC(here->CPLibr2PosPtr, double, noL, noL);
            MATRIX_ALLOC(here->CPLibr1Ibr2Ptr, double, noL, noL);
            MATRIX_ALLOC(here->CPLibr2Ibr1Ptr, double, noL, noL);


            branchname = TMALLOC(char *, here->dimension);
            if (! here->CPLibr1Given) {
                for (m = 0; m < here->dimension; m++) {
                    branchname[m] = TMALLOC(char, MAX_STRING);
                    sprintf(branchname[m], "branch1_%d", m);
                    error =
                        CKTmkCur(ckt, &tmp, here->CPLname, branchname[m]);
                    if (error) return (error);
                    here->CPLibr1[m] = tmp->number;
                    tfree(branchname[m]);
                }
                here->CPLibr1Given = 1;
            }
            free(branchname);
            branchname = TMALLOC(char *, here->dimension);
            if (! here->CPLibr2Given) {
                for (m = 0; m < here->dimension; m++) {
                    branchname[m] = TMALLOC(char, MAX_STRING);
                    sprintf(branchname[m], "branch2_%d", m);
                    error =
                        CKTmkCur(ckt, &tmp, here->CPLname, branchname[m]);
                    if (error) return (error);
                    here->CPLibr2[m] = tmp->number;
                    tfree(branchname[m]);
                }
                here->CPLibr2Given = 1;
            }
            free(branchname);

            for (m = 0; m < here->dimension; m++) {
                for (node = ckt->CKTnodes; node; node = node->next) {
                    if (strcmp(here->in_node_names[m],
                               node->name) == 0) {
                        here->CPLposNodes[m] = node->number;
                    }
                }
            }
            for (m = 0; m < here->dimension; m++) {
                for (node = ckt->CKTnodes; node; node = node->next) {
                    if (strcmp(here->out_node_names[m],
                               node->name) == 0) {
                        here->CPLnegNodes[m] = node->number;
                    }
                }
            }

            for (m = 0; m < here->dimension; m++) {
                TSTALLOC(CPLibr1Ibr1Ptr[m],CPLibr1[m],CPLibr1[m]);
                TSTALLOC(CPLibr2Ibr2Ptr[m],CPLibr2[m],CPLibr2[m]);
                TSTALLOC(CPLposIbr1Ptr[m],CPLposNodes[m],CPLibr1[m]);
                TSTALLOC(CPLnegIbr2Ptr[m],CPLnegNodes[m],CPLibr2[m]);
                TSTALLOC(CPLposPosPtr[m],CPLposNodes[m],CPLposNodes[m]);
                TSTALLOC(CPLnegNegPtr[m],CPLnegNodes[m],CPLnegNodes[m]);
                TSTALLOC(CPLnegPosPtr[m],CPLnegNodes[m],CPLposNodes[m]);
                TSTALLOC(CPLposNegPtr[m],CPLposNodes[m],CPLnegNodes[m]);

                for (p = 0; p < here->dimension; p++) {

                    TSTALLOC(CPLibr1PosPtr[m][p],CPLibr1[m],CPLposNodes[p]);
                    TSTALLOC(CPLibr2NegPtr[m][p],CPLibr2[m],CPLnegNodes[p]);
                    TSTALLOC(CPLibr1NegPtr[m][p],CPLibr1[m],CPLnegNodes[p]);
                    TSTALLOC(CPLibr2PosPtr[m][p],CPLibr2[m],CPLposNodes[p]);
                    TSTALLOC(CPLibr1Ibr2Ptr[m][p],CPLibr1[m],CPLibr2[p]);
                    TSTALLOC(CPLibr2Ibr1Ptr[m][p],CPLibr2[m],CPLibr1[p]);

                }
            }

            ReadCpL(here, ckt);

        }
    }

    return(OK);
}



int
CPLunsetup(GENmodel *inModel, CKTcircuit *ckt)
{
    CPLmodel *model;
    CPLinstance *here;
    int m;
    int noL;

    for (model = (CPLmodel *) inModel; model != NULL;
            model = model->CPLnextModel) {
        for (here = model->CPLinstances; here != NULL;
                here = here->CPLnextInstance) {

            noL = here->dimension;

            VECTOR_FREE(here->CPLibr1Ibr1Ptr);
            VECTOR_FREE(here->CPLibr2Ibr2Ptr);
            VECTOR_FREE(here->CPLposIbr1Ptr);
            VECTOR_FREE(here->CPLnegIbr2Ptr);
            VECTOR_FREE(here->CPLposPosPtr);
            VECTOR_FREE(here->CPLnegNegPtr);
            VECTOR_FREE(here->CPLnegPosPtr);
            VECTOR_FREE(here->CPLposNegPtr);


            MATRIX_FREE(here->CPLibr1PosPtr, noL, noL);
            MATRIX_FREE(here->CPLibr2NegPtr, noL, noL);
            MATRIX_FREE(here->CPLibr1NegPtr, noL, noL);
            MATRIX_FREE(here->CPLibr2PosPtr, noL, noL);
            MATRIX_FREE(here->CPLibr1Ibr2Ptr, noL, noL);
            MATRIX_FREE(here->CPLibr2Ibr1Ptr, noL, noL);


            for (m = 0; m < noL; m++) {
                if (here->CPLibr2[m]) {
                    CKTdltNNum(ckt, here->CPLibr2[m]);
                    here->CPLibr2[m] = 0;
                }
            }

            for (m = 0; m < noL; m++) {
                if (here->CPLibr1[m]) {
                    CKTdltNNum(ckt, here->CPLibr1[m]);
                    here->CPLibr1[m] = 0;
                }
            }

            free(here->CPLposNodes);
            free(here->CPLnegNodes);
            free(here->CPLibr1);
            free(here->CPLibr2);

            /* reset switches */
            here->CPLdcGiven=0;
            here->CPLibr1Given = 0;
            here->CPLibr2Given = 0;
        }
    }
    return OK;
}



static int
ReadCpL(CPLinstance *here, CKTcircuit *ckt)
{
    int i, j, noL, counter;
    double f;
    char *name;
    CPLine *c, *c2;
    ECPLine *ec;
    NODE *nd;
    RLINE *lines[MAX_CP_TX_LINES];
    ERLINE *er;

    c = TMALLOC(CPLine, 1);
    c2 = TMALLOC(CPLine, 1);
    c->vi_head = c->vi_tail = NULL;
    noL = c->noL = here->dimension;
    here->cplines = c;
    here->cplines2 = c2;

    for (i = 0; i < noL; i++) {
        ec = TMALLOC(ECPLine, 1);
        name = here->in_node_names[i];
        nd = insert_node(name);
        ec->link = nd->cplptr;
        nd->cplptr = ec;
        ec->line = c;
        c->in_node[i] = nd;
        c2->in_node[i] = nd;

        er = TMALLOC(ERLINE, 1);
        er->link = nd->rlptr;
        nd->rlptr = er;
        er->rl = lines[i] = TMALLOC(RLINE, 1);
        er->rl->in_node = nd;

        c->dc1[i] = c->dc2[i] = 0.0;
    }

    for (i = 0; i < noL; i++) {
        ec = TMALLOC(ECPLine, 1);
        name = here->out_node_names[i];
        nd = insert_node(name);
        ec->link = nd->cplptr;
        nd->cplptr = ec;
        ec->line = c;
        c->out_node[i] = nd;
        c2->out_node[i] = nd;

        er = TMALLOC(ERLINE, 1);
        er->link = nd->rlptr;
        nd->rlptr = er;
        er->rl = lines[i];
        er->rl->out_node = nd;
    }


    counter = 0;
    for (i = 0; i < noL; i++) {
        for (j = 0; j < noL; j++) {
            if (i > j) {
                R_m[i][j] = R_m[j][i];
                G_m[i][j] = G_m[j][i];
                C_m[i][j] = C_m[j][i];
                L_m[i][j] = L_m[j][i];
            } else {
                f = here->CPLmodPtr->Rm[counter];
                R_m[i][j] = here->CPLmodPtr->Rm[counter] = MAX(f, 1.0e-4);
                G_m[i][j] = here->CPLmodPtr->Gm[counter];
                L_m[i][j] = here->CPLmodPtr->Lm[counter];
                C_m[i][j] = here->CPLmodPtr->Cm[counter];
                counter++;
            }
        }
    }
    if (here->CPLlengthGiven)
        length = here->CPLlength;
    else length = here->CPLmodPtr->length;

    for (i = 0; i < noL; i++)
        lines[i]->g = 1.0 / (R_m[i][i] * length);

    coupled(noL);

    for (i = 0; i < noL; i++) {
        double d, t;
        int k;

        c->taul[i] = TAU[i] * 1.0e+12;
        for (j  = 0; j < noL; j++) {
            if (SIV[i][j].C_0 == 0.0)
                c->h1t[i][j] = NULL;
            else {
                c->h1t[i][j] = TMALLOC(TMS, 1);
                d = c->h1t[i][j]->aten = SIV[i][j].C_0;
                c->h1t[i][j]->ifImg = (int) (SIV[i][j].Poly[6] - 1.0);
                /* since originally 2 for img 1 for noimg */
                c->h1t[i][j]->tm[0].c = SIV[i][j].Poly[0] * d;
                c->h1t[i][j]->tm[1].c = SIV[i][j].Poly[1] * d;
                c->h1t[i][j]->tm[2].c = SIV[i][j].Poly[2] * d;
                c->h1t[i][j]->tm[0].x = SIV[i][j].Poly[3];
                c->h1t[i][j]->tm[1].x = SIV[i][j].Poly[4];
                c->h1t[i][j]->tm[2].x = SIV[i][j].Poly[5];
                if (c->h1t[i][j]->ifImg)
                    c->h1C[i][j] = c->h1t[i][j]->tm[0].c + 2.0 * c->h1t[i][j]->tm[1].c;
                else {
                    t = 0.0;
                    for (k = 0; k < 3; k++)
                        t += c->h1t[i][j]->tm[k].c;
                    c->h1C[i][j] = t;
                }
            }

            for (k = 0; k < noL; k++) {
                if (IWI[i][j].C_0[k] == 0.0)
                    c->h2t[i][j][k] = NULL;
                else {
                    c->h2t[i][j][k] = TMALLOC(TMS, 1);
                    d = c->h2t[i][j][k]->aten = IWI[i][j].C_0[k];
                    c->h2t[i][j][k]->ifImg = (int) (IWI[i][j].Poly[k][6] - 1.0);
                    /* since originally 2 for img 1 for noimg */
                    c->h2t[i][j][k]->tm[0].c = IWI[i][j].Poly[k][0] * d;
                    c->h2t[i][j][k]->tm[1].c = IWI[i][j].Poly[k][1] * d;
                    c->h2t[i][j][k]->tm[2].c = IWI[i][j].Poly[k][2] * d;
                    c->h2t[i][j][k]->tm[0].x = IWI[i][j].Poly[k][3];
                    c->h2t[i][j][k]->tm[1].x = IWI[i][j].Poly[k][4];
                    c->h2t[i][j][k]->tm[2].x = IWI[i][j].Poly[k][5];
                    if (c->h2t[i][j][k]->ifImg)
                        c->h2C[i][j][k] = c->h2t[i][j][k]->tm[0].c + 2.0 *
                                          c->h2t[i][j][k]->tm[1].c;
                    else
                        c->h2C[i][j][k] =  c->h2t[i][j][k]->tm[0].c +
                                           c->h2t[i][j][k]->tm[1].c +
                                           c->h2t[i][j][k]->tm[2].c;
                }
                if (IWV[i][j].C_0[k] == 0.0)
                    c->h3t[i][j][k] = NULL;
                else {
                    c->h3t[i][j][k] = TMALLOC(TMS, 1);
                    d = c->h3t[i][j][k]->aten = IWV[i][j].C_0[k];
                    c->h3t[i][j][k]->ifImg = (int) (IWV[i][j].Poly[k][6] - 1.0);
                    /* since originally 2 for img 1 for noimg */
                    c->h3t[i][j][k]->tm[0].c = IWV[i][j].Poly[k][0] * d;
                    c->h3t[i][j][k]->tm[1].c = IWV[i][j].Poly[k][1] * d;
                    c->h3t[i][j][k]->tm[2].c = IWV[i][j].Poly[k][2] * d;
                    c->h3t[i][j][k]->tm[0].x = IWV[i][j].Poly[k][3];
                    c->h3t[i][j][k]->tm[1].x = IWV[i][j].Poly[k][4];
                    c->h3t[i][j][k]->tm[2].x = IWV[i][j].Poly[k][5];
                    if (c->h3t[i][j][k]->ifImg)
                        c->h3C[i][j][k] = c->h3t[i][j][k]->tm[0].c + 2.0 *
                                          c->h3t[i][j][k]->tm[1].c;
                    else
                        c->h3C[i][j][k] =  c->h3t[i][j][k]->tm[0].c +
                                           c->h3t[i][j][k]->tm[1].c +
                                           c->h3t[i][j][k]->tm[2].c;
                }
            }
        }
    }

    for (i = 0; i < noL; i++) {
        if (c->taul[i] < ckt->CKTmaxStep) {
            errMsg = TMALLOC(char, strlen(message) + 1);
            strcpy(errMsg,message);
            return(-1);
        }
    }

    return(1);
}


/****************************************************************
     misc.c      Miscellaneous procedures for simulation of
                 coupled transmission lines.
 ****************************************************************/


static void
new_memory(int dim, int deg, int deg_o)
{
    int i, j;

    NG_IGNORE(deg);

    for (i = 0; i < dim; i++)
        for (j = 0; j < dim; j++)
            SiSv_1[i][j] = (double *) calloc((size_t) (deg_o+1), sizeof(double));

    for (i = 0; i < dim; i++)
        for (j = 0; j < dim; j++)
            Sip[i][j] = (double *) calloc((size_t) (deg_o+1), sizeof(double));

    for (i = 0; i < dim; i++)
        for (j = 0; j < dim; j++)
            Si_1p[i][j] = (double *) calloc((size_t) (deg_o+1), sizeof(double));

    for (i = 0; i < dim; i++)
        for (j = 0; j < dim; j++)
            Sv_1p[i][j] = (double *) calloc((size_t) (deg_o+1), sizeof(double));

    for (i = 0; i < dim; i++)
        W[i] = (double *) calloc(MAX_DEG, sizeof(double));
}

/***
 ***/

/****************************************************************
     match     Create a polynomial matching given data points
 ****************************************************************/


static double *
vector(int nl, int nh)
{
    double *v = TMALLOC(double, nh - nl + 1);

    if (!v) {
        fprintf(stderr, "Memory Allocation Error by tmalloc in vector().\n");
        fprintf(stderr, "...now exiting to system ...\n");
        controlled_exit(EXIT_FAILURE);
    }

    return v - nl;
}

static void
free_vector(double *v, int nl, int nh)
{
    NG_IGNORE(nh);

    free(v + nl);
}

static void
polint(double *xa, double *ya, int n, double x, double *y, double *dy)
/*
   Given arrays xa[1..n] and ya[1..n], and given a value x, this routine
   returns a value y, and an error estimate dy.  If P(x) is the
   polynomial of degree n-1 such that P(xa) = ya, then the returned
   value y = P(x)
 */
{
    int i, m, ns = 1;
    double den, dif, dift, ho, hp, w;
    double *c, *d;

    dif = ABS(x - xa[1]);
    c = vector(1, n);
    d = vector(1, n);
    for (i = 1; i <= n; i++) {
        if ((dift = ABS(x - xa[i])) < dif) {
            ns = i;
            dif = dift;
        }
        c[i] = ya[i];
        d[i] = ya[i];
    }
    *y = ya[ns--];
    for (m = 1; m < n; m++) {
        for (i = 1; i <= n-m; i++) {
            ho = xa[i]-x;
            hp = xa[i+m]-x;
            w = c[i+1]-d[i];
            if ((den=ho-hp) == 0.0) {
                fprintf(stderr, "(Error) in routine POLINT\n");
                fprintf(stderr, "...now exiting to system ...\n");
                controlled_exit(EXIT_FAILURE);
            }
            den = w/den;
            d[i] = hp * den;
            c[i] = ho * den;
        }
        *y += (*dy = (2*ns < (n-m) ? c[ns+1] : d[ns--]));
    }
    free_vector(d, 1, n);
    free_vector(c, 1, n);
}

static int
match(int n, double *cof, double *xa, double *ya)
/*
   Given arrays xa[0..n] and ya[0..n] containing a tabulated function
   ya = f(xa), this routine returns an array of coefficients cof[0..n],
   such that ya[i] = sum_j {cof[j]*xa[i]**j}.
 */
{
    int k, j, i;
    double xmin, dy, *x, *y, *xx;

    x = vector(0, n);
    y = vector(0, n);
    xx = vector(0, n);
    for (j = 0; j <= n; j++) {
        x[j] = xa[j];
        xx[j] = y[j] = ya[j];
    }
    for (j = 0; j <= n; j++) {
        polint(x-1, y-1, n+1-j, 0.0, &cof[j], &dy);
        xmin = 1.0e38;
        k = -1;
        for (i = 0; i <= n-j; i++) {
            if (ABS(x[i]) < xmin) {
                xmin = ABS(x[i]);
                k = i;
            }
            if (x[i]) y[i] = (y[i] - cof[j]) / x[i];
        }
        for (i = k+1; i <= n-j; i++) {
            y[i-1] = y[i];
            x[i-1] = x[i];
        }
    }
    free_vector(y, 0, n);
    free_vector(x, 0, n);
    free_vector(xx, 0, n);

    /****   check   ****/
    /*
    for (i = 0; i <= n; i++) {
       xmin = xa[i];
       dy = cof[0];
       for (j = 1; j <= n; j++) {
          dy += xmin * cof[j];
          xmin *= xa[i];
       }
       printf("*** real x = %e y = %e\n", xa[i], xx[i]);
       printf("*** calculated  y = %e\n", dy);
       printf("*** error = %e \% \n", (dy-xx[i])/xx[i]);
    }
    */
    return 0;
}

/***
 ***/
/***
static int
match_x(int dim, double *Alfa, double *X, double *Y)
{
   int i, j;
   double f;
   double scale;

   ****   check   ****
   double xx[16];
   for (i = 0; i <= dim; i++)
      xx[i] = Y[i];

   if (Y[1] == Y[0])
      scale = 1.0;
   else
      scale = X[1] / (Y[1] - Y[0]);
   for (i = 0; i < dim; i++) {
      f = X[i+1];
      for (j = dim-1; j >= 0; j--) {
         A[i][j] = f;
         f *= X[i+1];
      }
      A[i][dim] = (Y[i+1] - Y[0])*scale;
   }
   Gaussian_Elimination2(dim, 1);
   Alfa[0] = Y[0];
   for (i = 1; i <= dim; i++)
      Alfa[i] = A[dim-i][dim] / scale;

   ****   check   ****
   *
   for (i = 0; i <= dim; i++) {
      f = X[i];
      scale = Alfa[0];
      for (j = 1; j <= dim; j++) {
         scale += f * Alfa[j];
         f *= X[i];
      }
      printf("*** real x = %e y = %e\n", X[i], xx[i]);
      printf("*** calculated  y = %e\n", scale);
      printf("*** error = %e \% \n", (scale-xx[i])/xx[i]);
   }
   *

   return(1);
}
***/
/***
 ***/

static int
Gaussian_Elimination2(int dims, int type)
/*  type = 1 : to solve a linear system
          -1 : to inverse a matrix  */
{
    int i, j, k, dim;
    double f;
    double max;
    int imax;

    if (type == -1)
        dim = 2 * dims;
    else
        dim = dims;

    for (i = 0; i < dims; i++) {
        imax = i;
        max = ABS(A[i][i]);
        for (j = i+1; j < dim; j++)
            if (ABS(A[j][i]) > max) {
                imax = j;
                max = ABS(A[j][i]);
            }
        if (max < epsilon) {
            fprintf(stderr, " can not choose a pivot (misc)\n");
            controlled_exit(EXIT_FAILURE);
        }
        if (imax != i)
            for (k = i; k <= dim; k++) {
                SWAP(double, A[i][k], A[imax][k]);
            }

        f = 1.0 / A[i][i];
        A[i][i] = 1.0;

        for (j = i+1; j <= dim; j++)
            A[i][j] *= f;

        for (j = 0; j < dims ; j++) {
            if (i == j)
                continue;
            f = A[j][i];
            A[j][i] = 0.0;
            for (k = i+1; k <= dim; k++)
                A[j][k] -= f * A[i][k];
        }
    }

    return(1);
}

/***

static void
eval_Si_Si_1(int dim, double y)
{
   int i, j, k;

   for (i = 0; i < dim; i++)
      for (j = 0; j < dim; j++) {
         Si_1[i][j] = 0.0;
         for (k = 0; k < dim; k++)
            if (k == j)
                        Si_1[i][j] += Sv_1[i][k] *
                                (y * R_m[k][j] + Scaling_F * L_m[k][j]);
            else
                        Si_1[i][j] += Sv_1[i][k] * L_m[k][j] * Scaling_F;
                        /
                        Si_1[i][j] *= Scaling_F;
                        /
      }

   for (i = 0; i < dim; i++)
      for (j = 0; j < dim; j++)
         Si_1[i][j] /= sqrt((double) D[i]);

   for (i = 0; i < dim; i++) {
      for (j = 0; j < dim; j++)
         A[i][j] = Si_1[i][j];
      for (j = dim; j < 2* dim; j++)
         A[i][j] = 0.0;
      A[i][i+dim] = 1.0;
   }
   Gaussian_Elimination2(dim, -1);

   for (i = 0; i < dim; i++)
      for (j = 0; j < dim; j++)
         Si[i][j] = A[i][j+dim];
}

***/

static void
eval_Si_Si_1(int dim, double y)
{
    int i, j, k;

    for (i = 0; i < dim; i++)
        for (j = 0; j < dim; j++) {
            Si_1[i][j] = 0.0;
            for (k = 0; k < dim; k++)
                Si_1[i][j] += Sv_1[i][k] * (y * R_m[k][j] + Scaling_F * L_m[k][j]);
            /*
            else
            Si_1[i][j] += Sv_1[i][k] * L_m[k][j] * Scaling_F;
            Si_1[i][j] *= Scaling_F;
             */
        }

    for (i = 0; i < dim; i++)
        for (j = 0; j < dim; j++)
            Si_1[i][j] /= sqrt(D[i]);

    for (i = 0; i < dim; i++) {
        for (j = 0; j < dim; j++)
            A[i][j] = Si_1[i][j];
        for (j = dim; j < 2* dim; j++)
            A[i][j] = 0.0;
        A[i][i+dim] = 1.0;
    }
    Gaussian_Elimination2(dim, -1);

    for (i = 0; i < dim; i++)
        for (j = 0; j < dim; j++)
            Si[i][j] = A[i][j+dim];
}

/***

static void
loop_ZY(int dim, double y)
{
   int i, j, k;
   double fmin, fmin1;

   for (i = 0; i < dim; i++)
      for (j = 0; j < dim; j++)
         if (i == j)
            ZY[i][j] = Scaling_F * C_m[i][i] + G_m[i] * y;
         else
            ZY[i][j] = Scaling_F * C_m[i][j];
   diag(dim);
   fmin = D[0];
   for (i = 1; i < dim; i++)
      if (D[i] < fmin)
         fmin = D[i];
   if (fmin < 0) {
      fprintf(stderr, "(Error) The capacitance matrix of the multiconductor system is not positive definite.\n");
      exit(0);
   } else {
      fmin = sqrt(fmin);
      fmin1 = 1 / fmin;
   }
   for (i = 0; i < dim; i++)
      D[i] = sqrt((double) D[i]);
   for (i = 0; i < dim; i++)
      for (j = 0; j < dim; j++) {
         Y5[i][j] = D[i] * Sv[j][i];
         Y5_1[i][j] = Sv[j][i] / D[i];
      }
   for (i = 0; i < dim; i++)
      for (j = 0; j < dim; j++) {
         Sv_1[i][j] = 0.0;
         for (k = 0; k < dim; k++)
            Sv_1[i][j] += Sv[i][k] * Y5[k][j];
      }
   for (i = 0; i < dim; i++)
      for (j = 0; j < dim; j++)
         Y5[i][j] = Sv_1[i][j];
   for (i = 0; i < dim; i++)
      for (j = 0; j < dim; j++) {
         Sv_1[i][j] = 0.0;
         for (k = 0; k < dim; k++)
            Sv_1[i][j] += Sv[i][k] * Y5_1[k][j];
      }
   for (i = 0; i < dim; i++)
      for (j = 0; j < dim; j++)
         Y5_1[i][j] = Sv_1[i][j];

   for (i = 0; i < dim; i++)
      for (j = 0; j < dim; j++) {
         ZY[i][j] = 0.0;
         for (k = 0; k < dim; k++)
            if (k == i)
               ZY[i][j] += (Scaling_F *  L_m[i][i] + R_m[i] * y) *
                               Y5[k][j];
            else
               ZY[i][j] += L_m[i][k] * Y5[k][j] * Scaling_F;
      }
   for (i = 0; i < dim; i++)
      for (j = 0; j < dim; j++) {
         Sv_1[i][j] = 0.0;
         for (k = 0; k < dim; k++)
            Sv_1[i][j] += Y5[i][k] * ZY[k][j];
      }
   for (i = 0; i < dim; i++)
      for (j = 0; j < dim; j++)
         ZY[i][j] = Sv_1[i][j];

   diag(dim);

   for (i = 0; i < dim; i++)
      for (j = 0; j < dim; j++) {
         Sv_1[i][j] = 0.0;
         for (k = 0; k < dim; k++)
            Sv_1[i][j] += Sv[k][i] * Y5[k][j];
         Sv_1[i][j] *= fmin1;
      }
   for (i = 0; i < dim; i++)
      for (j = 0; j < dim; j++) {
         ZY[i][j] = 0.0;
         for (k = 0; k < dim; k++)
            ZY[i][j] += Y5_1[i][k] * Sv[k][j];
         ZY[i][j] *= fmin;
      }
   for (i = 0; i < dim; i++)
      for (j = 0; j < dim; j++)
         Sv[i][j] = ZY[i][j];

}
***/

static void
loop_ZY(int dim, double y)
{
    int i, j, k;
    double fmin, fmin1=0.0;

    for (i = 0; i < dim; i++)
        for (j = 0; j < dim; j++)
            ZY[i][j] = Scaling_F * C_m[i][j] + G_m[i][j] * y;
    /*
    else
    ZY[i][j] = Scaling_F * C_m[i][j];
     */
    diag(dim);
    fmin = D[0];
    for (i = 1; i < dim; i++)
        if (D[i] < fmin)
            fmin = D[i];
    if (fmin < 0) {
        fprintf(stderr, "(Error) The capacitance matrix of the multiconductor system is not positive definite.\n");
        controlled_exit(EXIT_FAILURE);
    } else {
        fmin = sqrt(fmin);
        fmin1 = 1 / fmin;
    }
    for (i = 0; i < dim; i++)
        D[i] = sqrt(D[i]);
    for (i = 0; i < dim; i++)
        for (j = 0; j < dim; j++) {
            Y5[i][j] = D[i] * Sv[j][i];
            Y5_1[i][j] = Sv[j][i] / D[i];
        }
    for (i = 0; i < dim; i++)
        for (j = 0; j < dim; j++) {
            Sv_1[i][j] = 0.0;
            for (k = 0; k < dim; k++)
                Sv_1[i][j] += Sv[i][k] * Y5[k][j];
        }
    for (i = 0; i < dim; i++)
        for (j = 0; j < dim; j++)
            Y5[i][j] = Sv_1[i][j];
    for (i = 0; i < dim; i++)
        for (j = 0; j < dim; j++) {
            Sv_1[i][j] = 0.0;
            for (k = 0; k < dim; k++)
                Sv_1[i][j] += Sv[i][k] * Y5_1[k][j];
        }
    for (i = 0; i < dim; i++)
        for (j = 0; j < dim; j++)
            Y5_1[i][j] = Sv_1[i][j];

    for (i = 0; i < dim; i++)
        for (j = 0; j < dim; j++) {
            ZY[i][j] = 0.0;
            for (k = 0; k < dim; k++)
                ZY[i][j] += (Scaling_F *  L_m[i][k] + R_m[i][k] * y) * Y5[k][j];
            /*
               else
                  ZY[i][j] += L_m[i][k] * Y5[k][j] * Scaling_F;
             */
        }
    for (i = 0; i < dim; i++)
        for (j = 0; j < dim; j++) {
            Sv_1[i][j] = 0.0;
            for (k = 0; k < dim; k++)
                Sv_1[i][j] += Y5[i][k] * ZY[k][j];
        }
    for (i = 0; i < dim; i++)
        for (j = 0; j < dim; j++)
            ZY[i][j] = Sv_1[i][j];

    diag(dim);

    for (i = 0; i < dim; i++)
        for (j = 0; j < dim; j++) {
            Sv_1[i][j] = 0.0;
            for (k = 0; k < dim; k++)
                Sv_1[i][j] += Sv[k][i] * Y5[k][j];
            Sv_1[i][j] *= fmin1;
        }
    for (i = 0; i < dim; i++)
        for (j = 0; j < dim; j++) {
            ZY[i][j] = 0.0;
            for (k = 0; k < dim; k++)
                ZY[i][j] += Y5_1[i][k] * Sv[k][j];
            ZY[i][j] *= fmin;
        }
    for (i = 0; i < dim; i++)
        for (j = 0; j < dim; j++)
            Sv[i][j] = ZY[i][j];

}


/***
 ***/

static void
poly_matrix(
    double *A[MAX_DIM][MAX_DIM],
    int dim, int deg)
{
    int i, j;

    for (i = 0; i < dim; i++)
        for (j = 0; j < dim; j++)
            match(deg, A[i][j], frequency, A[i][j]);
}

/***
 ***/
/***
static int
checkW(double *W, double d)
{
  double f, y;
  float  y1;
  int k;

  printf("(W)y =");
  scanf("%f", &y1);

  f = W[0];
  y = y1;
  f += y * W[1];
  for (k = 2; k < 6; k++) {
     y *= y1;
     f += y * W[k];
  }
  printf("W[i]= %e\n ", f*exp((double)-d/y1));

  return(1);
}
***/
/***
 ***/

static void
poly_W(int dim, int deg)
{
    int i;

    for (i = 0; i < dim; i++) {
        match(deg, W[i], frequency, W[i]);
        TAU[i] = approx_mode(W[i], W[i], length);
        /*
        checkW(W[i], TAU[i]);
        */
    }
}

/***
 ***/

static void
eval_frequency(int dim, int deg_o)
{
    int i;
    double min;

    min = D[0];

    for (i = 1; i < dim; i++)
        if (D[i] < min) {
            min = D[i];
        }

    if (min <= 0) {
        fprintf(stderr, "A mode frequency is not positive.  Abort!\n");
        controlled_exit(EXIT_FAILURE);
    }

    Scaling_F2 = 1.0 / min;
    Scaling_F = sqrt(Scaling_F2);
    min = length * 8.0;
    /*
    min *= 1.0e18;
    min = sqrt(min)*1.0e-9*length/8.0;
     */

    frequency[0] = 0.0;

    for (i = 1; i <= deg_o; i++)
        frequency[i] = frequency[i-1] + min;

    for (i = 0; i < dim; i++)
        D[i] *= Scaling_F2;
}

/***
 ***/

static void
store(int dim, int ind)
{
    int i, j;

    for (i = 0; i < dim; i++) {
        for (j = 0; j < dim; j++) {
            /*  store_Sip  */
            Sip[i][j][ind] = Si[i][j];
            /*  store_Si_1p  */
            Si_1p[i][j][ind] = Si_1[i][j];
            /*  store_Sv_1p  */
            Sv_1p[i][j][ind] = Sv_1[i][j];
        }
        /*  store_W  */
        W[i][ind] = D[i];
    }
}

/***
 ***/

static void
store_SiSv_1(int dim, int ind)
{
    int i, j, k;
    double temp;

    for (i = 0; i < dim; i++)
        for (j = 0; j < dim; j++) {
            temp = 0.0;
            for (k = 0; k < dim; k++)
                temp += Si[i][k] * Sv_1[k][j];
            SiSv_1[i][j][ind] = temp;
        }
}

/***
 ***/
/***
static int
check(Sip, Si_1p, Sv_1p, SiSv_1p)
   double *Sip[MAX_DIM][MAX_DIM];
   double *Si_1p[MAX_DIM][MAX_DIM];
   double *Sv_1p[MAX_DIM][MAX_DIM];
   double *SiSv_1p[MAX_DIM][MAX_DIM];
{
   double f, y;
   float  y1;
   int i, j, k;

   printf("y =");
   scanf("%f", &y1);

   printf("\n");
   printf("Si =\n");
   for (i = 0; i < 4; i++) {
      for (j = 0; j < 4; j++) {
         f = Sip[i][j][0];
         y = y1;
         f += y * Sip[i][j][1];
         for (k = 2; k < 8; k++) {
            y *= y1;
            f += y * Sip[i][j][k];
         }
         printf("%e ", f);
      }
      printf("\n");
   }
   printf("\n");
   printf("Si_1 =\n");
   for (i = 0; i < 4; i++) {
      for (j = 0; j < 4; j++) {
         f = Si_1p[i][j][0];
         y = y1;
         f += y * Si_1p[i][j][1];
         for (k = 2; k < 8; k++) {
            y *= y1;
            f += y * Si_1p[i][j][k];
         }
         printf("%e ", f);
      }
      printf("\n");
   }
   printf("\n");
   printf("Sv_1 =\n");
   for (i = 0; i < 4; i++) {
      for (j = 0; j < 4; j++) {
         f = Sv_1p[i][j][0];
         y = y1;
         f += y * Sv_1p[i][j][1];
         for (k = 2; k < 8; k++) {
            y *= y1;
            f += y * Sv_1p[i][j][k];
         }
         printf("%e ", f);
      }
      printf("\n");
   }
   printf("\n");
   printf("SiSv_1 =\n");
   for (i = 0; i < 4; i++) {
      for (j = 0; j < 4; j++) {
         f = SiSv_1p[i][j][0];
         y = y1;
         f += y * SiSv_1p[i][j][1];
         for (k = 2; k < 8; k++) {
            y *= y1;
            f += y * SiSv_1p[i][j][k];
         }
         printf("%e ", f);
      }
      printf("\n");
   }
   return(1);
}
***/
/***
 ***/

static int
coupled(int dim)
{
    int deg, deg_o;
    int i;

    deg = Right_deg;
    deg_o =  Left_deg;
    new_memory(dim, deg, deg_o);

    Scaling_F = Scaling_F2 = 1.0;

    /***     y = 0 : ZY = LC    ***/
    loop_ZY(dim, 0.0);
    eval_frequency(dim, deg_o);
    eval_Si_Si_1(dim, 0.0);
    store_SiSv_1(dim, 0);
    store(dim, 0);

    /***     Step  1     ***/
    /***     Step  2     ***/
    for (i = 1; i <= deg_o; i++) {
        loop_ZY(dim, frequency[i]);
        eval_Si_Si_1(dim, frequency[i]);
        store_SiSv_1(dim, i);
        store(dim, i);
    }
    poly_matrix(Sip, dim, deg_o);
    poly_matrix(Si_1p, dim, deg_o);
    poly_matrix(Sv_1p, dim, deg_o);
    poly_W(dim, deg_o);
    matrix_p_mult(Sip, W, Si_1p, dim, deg_o, deg_o, IWI);
    matrix_p_mult(Sip, W, Sv_1p, dim, deg_o, deg_o, IWV);

    poly_matrix(SiSv_1, dim, deg_o);

    /***
    check(Sip, Si_1p, Sv_1p, SiSv_1);
    ***/

    generate_out(dim, deg_o);

    return(1);
}

/***
 ***/

static int
generate_out(int dim, int deg_o)
{
    int i, j, k, rtv;
    double C;
    double *p;
    double c1, c2, c3, x1, x2, x3;

    for (i = 0; i < dim; i++)
        for (j = 0; j < dim; j++) {
            p = SiSv_1[i][j];
            SIV[i][j].C_0 = C = p[0];
            if (C == 0.0)
                continue;
            for (k = 0; k <= deg_o; k++)
                p[k] /= C;
            if (i == j) {
                rtv = Pade_apx(sqrt(G_m[i][i] / R_m[i][i]) / C,
                               p, &c1, &c2, &c3, &x1, &x2, &x3);
                if (rtv == 0) {
                    SIV[i][j].C_0 = 0.0;
                    printf("SIV\n");
                    continue;
                }
            } else {
                rtv = Pade_apx(0.0,
                               p, &c1, &c2, &c3, &x1, &x2, &x3);
                if (rtv == 0) {
                    SIV[i][j].C_0 = 0.0;
                    printf("SIV\n");
                    continue;
                }
            }
            p = SIV[i][j].Poly = (double *) calloc(7, sizeof(double));
            p[0] = c1;
            p[1] = c2;
            p[2] = c3;
            p[3] = x1;
            p[4] = x2;
            p[5] = x3;
            p[6] = rtv;
        }
    for (i = 0; i < dim; i++)
        for (j = 0; j < dim; j++)
            for (k = 0; k < dim; k++) {
                p = IWI[i][j].Poly[k];
                C = IWI[i][j].C_0[k];
                if (C == 0.0)
                    continue;
                if (i == j && k == i) {
                    rtv = Pade_apx(
                              exp(- sqrt(G_m[i][i] * R_m[i][i]) * length) / C,
                              p, &c1, &c2, &c3, &x1, &x2, &x3);
                    if (rtv == 0) {
                        IWI[i][j].C_0[k] = 0.0;
                        printf("IWI %d %d %d\n", i, j, k);
                        continue;
                    }
                } else {
                    rtv = Pade_apx(0.0,
                                   p, &c1, &c2, &c3, &x1, &x2, &x3);
                    if (rtv == 0) {
                        IWI[i][j].C_0[k] = 0.0;
                        printf("IWI %d %d %d\n", i, j, k);
                        continue;
                    }
                }
                p[0] = c1;
                p[1] = c2;
                p[2] = c3;
                p[3] = x1;
                p[4] = x2;
                p[5] = x3;
                p[6] = rtv;
            }

    for (i = 0; i < dim; i++)
        for (j = 0; j < dim; j++)
            for (k = 0; k < dim; k++) {
                p = IWV[i][j].Poly[k];
                C = IWV[i][j].C_0[k];
                if (C == 0.0)
                    continue;
                if (i == j && k == i) {
                    rtv = Pade_apx(sqrt(G_m[i][i] / R_m[i][i]) *
                                   exp(- sqrt(G_m[i][i] * R_m[i][i]) * length) / C,
                                   p, &c1, &c2, &c3, &x1, &x2, &x3);
                    if (rtv == 0) {
                        IWV[i][j].C_0[k] = 0.0;
                        printf("IWV %d %d %d\n", i, j, k);
                        continue;
                    }
                } else {
                    rtv = Pade_apx(0.0,
                                   p, &c1, &c2, &c3, &x1, &x2, &x3);
                    if (rtv == 0) {
                        IWV[i][j].C_0[k] = 0.0;
                        printf("IWV %d %d %d\n", i, j, k);
                        continue;
                    }
                }
                p[0] = c1;
                p[1] = c2;
                p[2] = c3;
                p[3] = x1;
                p[4] = x2;
                p[5] = x3;
                p[6] = rtv;
            }
    return(1);
}

/****************************************************************
     mult.c     Multiplication for Matrix of Polynomial
                   X(y) = A(y) D(y) B(y),
                   where D(y) is a diagonal matrix with each
                   diagonal entry of the form
                           e^{-a_i s}d(y), for which s = 1/y
                                                 and i = 1..N.
                   Each entry of X(y) will be of the form
                      \sum_{i=1}^N c_i e^{-a_i s} b_i(y), where
                      b_i(0) = 1; therefore, those
                      b_i(y)'s will be each entry's output.
 ****************************************************************/

static void
mult_p(double *p1, double *p2, double *p3, int d1, int d2, int d3)
/*   p3 = p1 * p2   */
{
    int i, j, k;

    for (i = 0; i <= d3; i++)
        p3[i] = 0.0;
    for (i = 0; i <= d1; i++)
        for (j = i, k = 0; k <= d2; j++, k++) {
            if (j > d3)
                break;
            p3[j] += p1[i] * p2[k];
        }
}


static void
matrix_p_mult(
    double  *A[MAX_DIM][MAX_DIM],
    double  *D[MAX_DIM],
    double  *B[MAX_DIM][MAX_DIM],
    int dim, int deg, int deg_o,
    Mult_Out  X[MAX_DIM][MAX_DIM])
{
    int i, j, k, l;
    double *p;
    double *T[MAX_DIM][MAX_DIM];
    double t1;

    for (i  = 0; i < dim; i++)
        for (j = 0; j < dim; j++) {
            p = T[i][j] = (double *) calloc((size_t) (deg_o+1), sizeof(double));
            mult_p(B[i][j], D[i], p, deg, deg_o, deg_o);
        }
    for (i  = 0; i < dim; i++)
        for (j = 0; j < dim; j++)
            for (k = 0; k < dim; k++) {
                p = X[i][j].Poly[k] =
                        (double *) calloc((size_t) (deg_o+1), sizeof(double));
                mult_p(A[i][k], T[k][j], p, deg, deg_o, deg_o);
                t1 = X[i][j].C_0[k] = p[0];
                if (t1 != 0.0) {
                    p[0] = 1.0;
                    for (l = 1; l <= deg_o; l++)
                        p[l] /= t1;
                }
            }
    for (i  = 0; i < dim; i++)
        for (j = 0; j < dim; j++)
            tfree(T[i][j]);

    /**********
    for (i  = 0; i < dim; i++)
    for (j = 0; j < dim; j++) {
          for (k = 0; k < dim; k++) {
          fprintf(outFile, "(%5.3f)", X[i][j].C_0[k]);
          p = X[i][j].Poly[k];
          for (l = 0; l <= deg_o; l++)
             fprintf(outFile, "%5.3f ", p[l]);
          fprintf(outFile, "\n");
       }
       fprintf(outFile, "\n");
    }
     ***********/
}

/****************************************************************
                  mode  approximation

 ****************************************************************/

/***
 ***/

static double
approx_mode(double *X, double *b, double length)
{
    double w0, w1, w2, w3, w4, w5;
    double a[8];
    double delay, atten;
    double y1, y2, y3, y4, y5, y6;
    int    i, j;

    w0 = X[0];
    w1 = X[1] / w0;  /* a */
    w2 = X[2] / w0;  /* b */
    w3 = X[3] / w0;  /* c */
    w4 = X[4] / w0;  /* d */
    w5 = X[5] / w0;  /* e */

    y1 = 0.5 * w1;
    y2 = w2 - y1 * y1;
    y3 = 3 * w3 - 3.0 * y1 * y2;
    y4 = 12.0 * w4 - 3.0 * y2 * y2 - 4.0 * y1 * y3;
    y5 = 60.0 * w5 - 5.0 * y1 * y4 -10.0 * y2 * y3;
    y6 = -10.0 * y3 * y3 - 15.0 * y2 * y4 - 6.0 * y1 * y5;

    delay = sqrt(w0) * length / Scaling_F;
    atten = exp(- delay * y1);

    a[1] = y2 / 2.0;
    a[2] = y3 / 6.0;
    a[3] = y4 / 24.0;
    a[4] = y5 / 120.0;
    a[5] = y6 / 720.0;

    a[1] *= -delay;
    a[2] *= -delay;
    a[3] *= -delay;
    a[4] *= -delay;
    a[5] *= -delay;

    b[0] = 1.0;
    b[1] = a[1];
    for (i = 2; i <= 5; i++) {
        b[i] = 0.0;
        for (j = 1; j <= i; j++)
            b[i] += j * a[j] * b[i-j];
        b[i] = b[i] / (double) i;
    }

    for (i = 0; i <= 5; i++)
        b[i] *= atten;

    return(delay);
}

/***
 ***/

static double
eval2(double a, double b, double c, double x)
{
    return(a*x*x + b*x + c);
}

/***
 ***/

static int
get_c(double q1, double q2, double q3, double p1, double p2, double a, double b,
      double *cr, double *ci)
{
    double d, n;

    d = (3.0*(a*a-b*b)+2.0*p1*a+p2)*(3.0*(a*a-b*b)+2.0*p1*a+p2);
    d += (6.0*a*b+2.0*p1*b)*(6.0*a*b+2.0*p1*b);
    n = -(q1*(a*a-b*b)+q2*a+q3)*(6.0*a*b+2.0*p1*b);
    n += (2.0*q1*a*b+q2*b)*(3.0*(a*a-b*b)+2.0*p1*a+p2);
    *ci = n/d;
    n = (3.0*(a*a-b*b)+2.0*p1*a+p2)*(q1*(a*a-b*b)+q2*a+q3);
    n += (6.0*a*b+2.0*p1*b)*(2.0*q1*a*b+q2*b);
    *cr = n/d;

    return(1);
}


static int
Pade_apx(double a_b, double *b, double *c1, double *c2, double *c3,
         double *x1, double *x2, double *x3)
/*
        b[0] + b[1]*y + b[2]*y^2 + ... + b[5]*y^5 + ...
      = (q3*y^3 + q2*y^2 + q1*y + 1) / (p3*y^3 + p2*y^2 + p1*y + 1)

        where b[0] is always equal to 1.0 and neglected,
          and y = 1/s.

        (q3*y^3 + q2*y^2 + q1*y + 1) / (p3*y^3 + p2*y^2 + p1*y + 1)
      = (s^3 + q1*s^2 + q2*s + q3) / (s^3 + p1*s^2 + p2*s + p3)
      = c1 / (s - x1) + c2 / (s - x2) + c3 / (s - x3) + 1.0
 */
{
    double p1, p2, p3, q1, q2, q3;

    At[0][0] = 1.0 - a_b;
    At[0][1] = b[1];
    At[0][2] = b[2];
    At[0][3] = -b[3];

    At[1][0] = b[1];
    At[1][1] = b[2];
    At[1][2] = b[3];
    At[1][3] = -b[4];

    At[2][0] = b[2];
    At[2][1] = b[3];
    At[2][2] = b[4];
    At[2][3] = -b[5];

    Gaussian_Elimination(3);

    p3 = At[0][3];
    p2 = At[1][3];
    p1 = At[2][3];
    /*
    if (p3 < 0.0 || p2 < 0.0 || p1 < 0.0 || p1*p2 <= p3)
       return(0);
     */
    q1 = p1 + b[1];
    q2 = b[1] * p1 + p2 + b[2];
    q3 = p3 * a_b;

    if (find_roots(p1, p2, p3, x1, x2, x3)) {
        /*
        printf("complex roots : %e %e %e \n", *x1, *x2, *x3);
         */
        *c1 = eval2(q1 - p1, q2 - p2, q3 - p3, *x1) /
              eval2(3.0, 2.0 * p1, p2, *x1);
        get_c(q1 - p1, q2 - p2, q3 - p3, p1, p2, *x2, *x3, c2, c3);
        return(2);
    } else {
        /* new
            printf("roots are %e %e %e \n", *x1, *x2, *x3);
            */
        *c1 = eval2(q1 - p1, q2 - p2, q3 - p3, *x1) /
              eval2(3.0, 2.0 * p1, p2, *x1);
        *c2 = eval2(q1 - p1, q2 - p2, q3 - p3, *x2) /
              eval2(3.0, 2.0 * p1, p2, *x2);
        *c3 = eval2(q1 - p1, q2 - p2, q3 - p3, *x3) /
              eval2(3.0, 2.0 * p1, p2, *x3);
        return(1);
    }
}

static int
Gaussian_Elimination(int dims)
{
    int i, j, k, dim;
    double f;
    double max;
    int imax;

    dim = dims;

    for (i = 0; i < dim; i++) {
        imax = i;
        max = ABS(At[i][i]);
        for (j = i+1; j < dim; j++)
            if (ABS(At[j][i]) > max) {
                imax = j;
                max = ABS(At[j][i]);
            }
        if (max < epsi_mult) {
            fprintf(stderr, " can not choose a pivot (mult)\n");
            controlled_exit(EXIT_FAILURE);
        }
        if (imax != i)
            for (k = i; k <= dim; k++) {
                SWAP(double, At[i][k], At[imax][k]);
            }

        f = 1.0 / At[i][i];
        At[i][i] = 1.0;

        for (j = i+1; j <= dim; j++)
            At[i][j] *= f;

        for (j = 0; j < dim ; j++) {
            if (i == j)
                continue;
            f = At[j][i];
            At[j][i] = 0.0;
            for (k = i+1; k <= dim; k++)
                At[j][k] -= f * At[i][k];
        }
    }
    return(1);
}

static double
root3(double a1, double a2, double a3, double x)
{
    double t1, t2;

    t1 = x * (x * (x + a1) + a2) + a3;
    t2 = x * (2.0*a1 + 3.0*x) + a2;

    return(x - t1 / t2);
}

static int
div3(double a1, double a2, double a3, double x, double *p1, double *p2)
{
    NG_IGNORE(a2);

    *p1 = a1 + x;

    /* *p2 = a2 + (a1 + x) * x; */

    *p2 = - a3 / x;

    return(1);
}


static int
find_roots(double a1, double a2, double a3, double *x1, double *x2, double *x3)
{
    double x, t;
    double p, q;

    /***********************************************
    double m,n;
    p = a1*a1/3.0 - a2;
    q = a1*a2/3.0 - a3 - 2.0*a1*a1*a1/27.0;
    p = p*p*p/27.0;
    t = q*q - 4.0*p;
    if (t < 0.0) {
       if (q != 0.0) {
          t = atan(sqrt((double)-t)/q);
          if (t < 0.0)
             t += M_PI;
          t /= 3.0;
          x = 2.0 * pow(p, 0.16666667) * cos(t) - a1 / 3.0;
       } else {
          t /= -4.0;
          x = pow(t, 0.16666667) * 1.732 - a1 / 3.0;
       }
    } else {
       t = sqrt(t);
       m = 0.5*(q - t);
       n = 0.5*(q + t);
       if (m < 0.0)
          m = -pow((double) -m, (double) 0.3333333);
       else
          m = pow((double) m, (double) 0.3333333);
       if (n < 0.0)
          n = -pow((double) -n, (double) 0.3333333);
       else
          n = pow((double) n, (double) 0.3333333);
       x = m + n - a1 / 3.0;
    }
     ************************************************/
    q = (a1*a1-3.0*a2) / 9.0;
    p = (2.0*a1*a1*a1-9.0*a1*a2+27.0*a3) / 54.0;
    t = q*q*q - p*p;
    if (t >= 0.0) {
        t = acos(p /(q * sqrt(q)));
        x = -2.0*sqrt(q)*cos(t / 3.0) - a1/3.0;
    } else {
        if (p > 0.0) {
            t = pow(sqrt(-t)+p, 1.0 / 3.0);
            x = -(t + q / t) - a1/3.0;
        } else if (p == 0.0) {
            x = -a1/3.0;
        } else {
            t = pow(sqrt(-t)-p, 1.0 / 3.0);
            x = (t + q / t) - a1/3.0;
        }
    }
    /*
    fprintf(stderr, "..1.. %e\n", x*x*x+a1*x*x+a2*x+a3);
     */
    {
        double x_backup = x;
        int i = 0;
        for (t = root3(a1, a2, a3, x); ABS(t-x) > 5.0e-4;
                t = root3(a1, a2, a3, x))
            if (++i == 32) {
                x = x_backup;
                break;
            } else
                x = t;
    }
    /*
    fprintf(stderr, "..2.. %e\n", x*x*x+a1*x*x+a2*x+a3);
     */


    *x1 = x;
    div3(a1, a2, a3, x, &a1, &a2);

    t = a1 * a1 - 4.0 * a2;
    if (t < 0) {
        /*
        fprintf(stderr, "***** Two Imaginary Roots.\n Update.\n");
        *x2 = -0.5 * a1;
        *x3 = a2 / *x2;
         */
        *x3 = 0.5 * sqrt(-t);
        *x2 = -0.5 * a1;
        return(1);
    } else {
        t = sqrt(t);
        if (a1 >= 0.0)
            *x2 = t = -0.5 * (a1 + t);
        else
            *x2 = t = -0.5 * (a1 - t);
        *x3 = a2 / t;
        return(0);
    }
}


static NDnamePt
insert_ND(char *name, NDnamePt *ndn)
{
    int       cmp;
    NDnamePt  p;

    if (*ndn == NULL) {
        p = *ndn = TMALLOC(NDname, 1);
        p->nd = NULL;
        p->right = p->left = NULL;
        strcpy(p->id, name);
        return(p);
    }
    cmp = strcmp((*ndn)->id, name);
    if (cmp == 0)
        return(*ndn);
    else {
        if (cmp < 0)
            return(insert_ND(name, &((*ndn)->left)));
        else
            return(insert_ND(name, &((*ndn)->right)));
    }
}

static NODE *
insert_node(char *name)
{
    NDnamePt n;
    NODE    *p;

    n = insert_ND(name, &ndn_btree);
    if (n->nd == NULL) {
        p = NEW_node();
        p->name = n;
        n->nd = p;
        p->next = node_tab;
        node_tab = p;
        return(p);
    } else
        return(n->nd);
}
/***
static int divC(double ar, double ai, double br, double bi, double *cr, double *ci)
{
        double t;

        t = br*br + bi*bi;
        *cr = (ar*br + ai*bi) / t;
        *ci = (ai*br - ar*bi) / t;

        return(1);
}
***/

static NODE
*NEW_node(void)
{
    NODE *n;

    n = TMALLOC(NODE, 1);
    n->mptr = NULL;
    n->gptr = NULL;
    n->cptr = NULL;
    n->rptr = NULL;
    n->tptr = NULL;
    n->cplptr = NULL;
    n->rlptr = NULL;
    n->ddptr = NULL;
    n->cvccsptr = NULL;
    n->vccsptr = NULL;
    n->CL = 0.001;
    n->V = n->dv = 0.0;
    n->gsum = n->cgsum = 0;
    n->is   = 0;
    n->tag  = 0;
    n->flag = 0;
    n->region = NULL;
    n->ofile = NULL;
    n->dvtag = 0;

    return(n);
}



/****************************************************************
     diag.c      This file contains the main().
 ****************************************************************/

#define  epsi2    1.0e-8

static  int         dim;
static  MAXE_PTR    row;

static MAXE_PTR
sort(MAXE_PTR list, double val, int r, int c, MAXE_PTR e)
{
    if (list == NULL || list->value < val) {
        e->row = r;
        e->col = c;
        e->value = val;
        e->next = list;
        return(e);
    } else {
        list->next = sort(list->next, val, r, c, e);
        return(list);
    }
}


static void
ordering(void)
{
    MAXE_PTR e;
    int i, j, m;
    double mv;

    for (i = 0; i < dim-1; i++) {
        m = i+1;
        mv = ABS(ZY[i][m]);
        for (j = m+1; j < dim; j++)
            if ((int)(ABS(ZY[i][j]) * 1e7) > (int) (1e7 *mv)) {

                mv = ABS(ZY[i][j]);
                m = j;
            }
        e = TMALLOC(MAXE, 1);
        row = sort(row, mv, i, m, e);
    }
}


static MAXE_PTR
delete_1(MAXE_PTR *list, int rc)
{
    MAXE_PTR list1, e;

    list1 = *list;
    if ((*list)->row == rc) {
        *list = (*list)->next;
        return(list1);
    }
    for (e = list1->next; e->row != rc; e = e->next)
        list1 = e;
    list1->next = e->next;
    return(e);
}


static void
reordering(int p, int q)
{
    MAXE_PTR e;
    int j, m;
    double mv;

    m = p+1;
    mv = ABS(ZY[p][m]);
    for (j = m+1; j < dim; j++)
        if ((int)(ABS(ZY[p][j]) * 1e7) > (int) (1e7 *mv)) {
            mv = ABS(ZY[p][j]);
            m = j;
        }
    e = delete_1(&row, p);
    row = sort(row, mv, p, m, e);

    m = q+1;
    if (m != dim) {
        mv = ABS(ZY[q][m]);
        for (j = m+1; j < dim; j++)
            if ((int)(ABS(ZY[q][j]) * 1e7) > (int) (1e7 *mv)) {

                mv = ABS(ZY[q][j]);
                m = j;
            }
        e = delete_1(&row, q);
        row = sort(row, mv, q, m, e);
    }

}

static void
diag(int dims)
{
    int i, j, c;
    double fmin, fmax;

    dim = dims;
    row = NULL;

    fmin = fmax = ABS(ZY[0][0]);
    for (i = 0; i < dim; i++)
        for (j = i; j < dim; j++)
            if (ABS(ZY[i][j]) > fmax)
                fmax = ABS(ZY[i][j]);
            else if (ABS(ZY[i][j]) < fmin)
                fmin = ABS(ZY[i][j]);
    fmin = 2.0 / (fmin + fmax);
    for (i = 0; i < dim; i++)
        for (j = i; j < dim; j++)
            ZY[i][j] *= fmin;

    for (i = 0; i < dim; i++) {
        for (j = 0; j < dim; j++)
            if (i == j)
                Sv[i][i] = 1.0;
            else
                Sv[i][j] = 0.0;
    }

    ordering();

    if (row)
        for (c = 0; row->value > epsi2; c++) {
            int p, q;

            p = row->row;
            q = row->col;

            rotate(dim, p, q);
            reordering(p, q);
        }

    for (i = 0; i < dim; i++)
        D[i] = ZY[i][i] / fmin;

    while (row) {
        MAXE_PTR tmp_row = row->next;
        tfree(row);
        row = tmp_row;
    }
}

/****************************************************************
     rotate()      rotation of the Jacobi's method
 ****************************************************************/

static int
rotate(int dim, int p, int q)
{
    int j;
    double co, si;
    double ve, mu, ld;
    double T[MAX_DIM];
    double t;

    ld = - ZY[p][q];
    mu = 0.5 * (ZY[p][p] - ZY[q][q]);
    ve = sqrt(ld*ld + mu*mu);
    co = sqrt((ve + ABS(mu)) / (2.0 * ve));
    si = SGN(mu) * ld / (2.0 * ve * co);

    for (j = p+1; j < dim; j++)
        T[j] = ZY[p][j];
    for (j = 0; j < p; j++)
        T[j] = ZY[j][p];

    for (j = p+1; j < dim; j++) {
        if (j == q)
            continue;
        if (j > q)
            ZY[p][j] = T[j] * co - ZY[q][j] * si;
        else
            ZY[p][j] = T[j] * co - ZY[j][q] * si;
    }
    for (j = q+1; j < dim; j++) {
        if (j == p)
            continue;
        ZY[q][j] = T[j] * si + ZY[q][j] * co;
    }
    for (j = 0; j < p; j++) {
        if (j == q)
            continue;
        ZY[j][p] = T[j] * co - ZY[j][q] * si;
    }
    for (j = 0; j < q; j++) {
        if (j == p)
            continue;
        ZY[j][q] = T[j] * si + ZY[j][q] * co;
    }

    t = ZY[p][p];
    ZY[p][p] = t * co * co + ZY[q][q] * si * si - 2.0 * ZY[p][q] * si * co;
    ZY[q][q] = t * si * si + ZY[q][q] * co * co + 2.0 * ZY[p][q] * si * co;

    ZY[p][q] = 0.0;

    {
        double R[MAX_DIM];

        for (j = 0; j < dim; j++) {
            T[j] = Sv[j][p];
            R[j] = Sv[j][q];
        }

        for (j = 0; j < dim; j++) {
            Sv[j][p] = T[j] * co - R[j] * si;
            Sv[j][q] = T[j] * si + R[j] * co;
        }
    }

    return(1);

}

