#include <math.h>

#include <stdlib.h>

#include <string.h>

#include <stdio.h>

#include <complex.h>

#ifdef complex

#undef complex

#endif

#ifdef I

#undef I

#endif

#if defined(_WIN64)

typedef long long BLASLONG;

typedef unsigned long long BLASULONG;

#else

typedef long BLASLONG;

typedef unsigned long BLASULONG;

#endif

#ifdef LAPACK_ILP64

typedef BLASLONG blasint;

#if defined(_WIN64)

#define blasabs(x) llabs(x)

#else

#define blasabs(x) labs(x)

#endif

#else

typedef int blasint;

#define blasabs(x) abs(x)

#endif

typedef blasint integer;

typedef unsigned int uinteger;

typedef char *address;

typedef short int shortint;

typedef float real;

typedef double doublereal;

typedef struct { real r, i; } complex;

typedef struct { doublereal r, i; } doublecomplex;

#ifdef _MSC_VER

static inline _Fcomplex Cf(complex *z) {_Fcomplex zz={z->r , z->i}; return zz;}

static inline _Dcomplex Cd(doublecomplex *z) {_Dcomplex zz={z->r , z->i};return zz;}

static inline _Fcomplex * _pCf(complex *z) {return (_Fcomplex*)z;}

static inline _Dcomplex * _pCd(doublecomplex *z) {return (_Dcomplex*)z;}

#else

static inline _Complex float Cf(complex *z) {return z->r + z->i*_Complex_I;}

static inline _Complex double Cd(doublecomplex *z) {return z->r + z->i*_Complex_I;}

static inline _Complex float * _pCf(complex *z) {return (_Complex float*)z;}

static inline _Complex double * _pCd(doublecomplex *z) {return (_Complex double*)z;}

#endif

#define pCf(z) (*_pCf(z))

#define pCd(z) (*_pCd(z))

typedef blasint logical;

typedef char logical1;

typedef char integer1;

#define TRUE_ (1)

#define FALSE_ (0)

/* Extern is for use with -E */

#ifndef Extern

#define Extern extern

#endif

/* I/O stuff */

typedef int flag;

typedef int ftnlen;

typedef int ftnint;

/*external read, write*/

typedef struct

{ flag cierr;

ftnint ciunit;

flag ciend;

char *cifmt;

ftnint cirec;

} cilist;

/*internal read, write*/

typedef struct

{ flag icierr;

char *iciunit;

flag iciend;

char *icifmt;

ftnint icirlen;

ftnint icirnum;

} icilist;

/*open*/

typedef struct

{ flag oerr;

ftnint ounit;

char *ofnm;

ftnlen ofnmlen;

char *osta;

char *oacc;

char *ofm;

ftnint orl;

char *oblnk;

} olist;

/*close*/

typedef struct

{ flag cerr;

ftnint cunit;

char *csta;

} cllist;

/*rewind, backspace, endfile*/

typedef struct

{ flag aerr;

ftnint aunit;

} alist;

/* inquire */

typedef struct

{ flag inerr;

ftnint inunit;

char *infile;

ftnlen infilen;

ftnint *inex; /*parameters in standard's order*/

ftnint *inopen;

ftnint *innum;

ftnint *innamed;

char *inname;

ftnlen innamlen;

char *inacc;

ftnlen inacclen;

char *inseq;

ftnlen inseqlen;

char *indir;

ftnlen indirlen;

char *infmt;

ftnlen infmtlen;

char *inform;

ftnint informlen;

char *inunf;

ftnlen inunflen;

ftnint *inrecl;

ftnint *innrec;

char *inblank;

ftnlen inblanklen;

} inlist;

#define VOID void

union Multitype { /* for multiple entry points */

integer1 g;

shortint h;

integer i;

/* longint j; */

real r;

doublereal d;

complex c;

doublecomplex z;

};

typedef union Multitype Multitype;

struct Vardesc { /* for Namelist */

};

typedef struct Vardesc Vardesc;

struct Namelist {

};

typedef struct Namelist Namelist;

#define abs(x) ((x) >= 0 ? (x) : -(x))

#define dabs(x) (fabs(x))

#define f2cmin(a,b) ((a) <= (b) ? (a) : (b))

#define f2cmax(a,b) ((a) >= (b) ? (a) : (b))

#define dmin(a,b) (f2cmin(a,b))

#define dmax(a,b) (f2cmax(a,b))

#define bit_test(a,b) ((a) >> (b) & 1)

#define bit_clear(a,b) ((a) & ~((uinteger)1 << (b)))

#define bit_set(a,b) ((a) | ((uinteger)1 << (b)))

#define abort_() { sig_die("Fortran abort routine called", 1); }

#define c_abs(z) (cabsf(Cf(z)))

#define c_cos(R,Z) { pCf(R)=ccos(Cf(Z)); }

#ifdef _MSC_VER

#define c_div(c, a, b) {Cf(c)._Val[0] = (Cf(a)._Val[0]/Cf(b)._Val[0]); Cf(c)._Val[1]=(Cf(a)._Val[1]/Cf(b)._Val[1]);}

#define z_div(c, a, b) {Cd(c)._Val[0] = (Cd(a)._Val[0]/Cd(b)._Val[0]); Cd(c)._Val[1]=(Cd(a)._Val[1]/df(b)._Val[1]);}

#else

#define c_div(c, a, b) {pCf(c) = Cf(a)/Cf(b);}

#define z_div(c, a, b) {pCd(c) = Cd(a)/Cd(b);}

#endif

#define c_exp(R, Z) {pCf(R) = cexpf(Cf(Z));}

#define c_log(R, Z) {pCf(R) = clogf(Cf(Z));}

#define c_sin(R, Z) {pCf(R) = csinf(Cf(Z));}

//#define c_sqrt(R, Z) {*(R) = csqrtf(Cf(Z));}

#define c_sqrt(R, Z) {pCf(R) = csqrtf(Cf(Z));}

#define d_abs(x) (fabs(*(x)))

#define d_acos(x) (acos(*(x)))

#define d_asin(x) (asin(*(x)))

#define d_atan(x) (atan(*(x)))

#define d_atn2(x, y) (atan2(*(x),*(y)))

#define d_cnjg(R, Z) { pCd(R) = conj(Cd(Z)); }

#define r_cnjg(R, Z) { pCf(R) = conjf(Cf(Z)); }

#define d_cos(x) (cos(*(x)))

#define d_cosh(x) (cosh(*(x)))

#define d_dim(__a, __b) ( *(__a) > *(__b) ? *(__a) - *(__b) : 0.0 )

#define d_exp(x) (exp(*(x)))

#define d_imag(z) (cimag(Cd(z)))

#define r_imag(z) (cimagf(Cf(z)))

#define d_int(__x) (*(__x)>0 ? floor(*(__x)) : -floor(- *(__x)))

#define r_int(__x) (*(__x)>0 ? floor(*(__x)) : -floor(- *(__x)))

#define d_lg10(x) ( 0.43429448190325182765 * log(*(x)) )

#define r_lg10(x) ( 0.43429448190325182765 * log(*(x)) )

#define d_log(x) (log(*(x)))

#define d_mod(x, y) (fmod(*(x), *(y)))

#define u_nint(__x) ((__x)>=0 ? floor((__x) + .5) : -floor(.5 - (__x)))

#define d_nint(x) u_nint(*(x))

#define u_sign(__a,__b) ((__b) >= 0 ? ((__a) >= 0 ? (__a) : -(__a)) : -((__a) >= 0 ? (__a) : -(__a)))

#define d_sign(a,b) u_sign(*(a),*(b))

#define r_sign(a,b) u_sign(*(a),*(b))

#define d_sin(x) (sin(*(x)))

#define d_sinh(x) (sinh(*(x)))

#define d_sqrt(x) (sqrt(*(x)))

#define d_tan(x) (tan(*(x)))

#define d_tanh(x) (tanh(*(x)))

#define i_abs(x) abs(*(x))

#define i_dnnt(x) ((integer)u_nint(*(x)))

#define i_len(s, n) (n)

#define i_nint(x) ((integer)u_nint(*(x)))

#define i_sign(a,b) ((integer)u_sign((integer)*(a),(integer)*(b)))

#define pow_dd(ap, bp) ( pow(*(ap), *(bp)))

#define pow_si(B,E) spow_ui(*(B),*(E))

#define pow_ri(B,E) spow_ui(*(B),*(E))

#define pow_di(B,E) dpow_ui(*(B),*(E))

#define pow_zi(p, a, b) {pCd(p) = zpow_ui(Cd(a), *(b));}

#define pow_ci(p, a, b) {pCf(p) = cpow_ui(Cf(a), *(b));}

#define pow_zz(R,A,B) {pCd(R) = cpow(Cd(A),*(B));}

#define s_cat(lpp, rpp, rnp, np, llp) { ftnlen i, nc, ll; char *f__rp, *lp; ll = (llp); lp = (lpp); for(i=0; i < (int)*(np); ++i) { nc = ll; if((rnp)[i] < nc) nc = (rnp)[i]; ll -= nc; f__rp = (rpp)[i]; while(--nc >= 0) *lp++ = *(f__rp)++; } while(--ll >= 0) *lp++ = ' '; }

#define s_cmp(a,b,c,d) ((integer)strncmp((a),(b),f2cmin((c),(d))))

#define s_copy(A,B,C,D) { int __i,__m; for (__i=0, __m=f2cmin((C),(D)); __i<__m && (B)[__i] != 0; ++__i) (A)[__i] = (B)[__i]; }

#define sig_die(s, kill) { exit(1); }

#define s_stop(s, n) {exit(0);}

static char junk[] = "\n@(#)LIBF77 VERSION 19990503\n";

#define z_abs(z) (cabs(Cd(z)))

#define z_exp(R, Z) {pCd(R) = cexp(Cd(Z));}

#define z_sqrt(R, Z) {pCd(R) = csqrt(Cd(Z));}

#define myexit_() break;

#define mycycle() continue;

#define myceiling(w) {ceil(w)}

#define myhuge(w) {HUGE_VAL}

//#define mymaxloc_(w,s,e,n) {if (sizeof(*(w)) == sizeof(double)) dmaxloc_((w),*(s),*(e),n); else dmaxloc_((w),*(s),*(e),n);}

#define mymaxloc(w,s,e,n) {dmaxloc_(w,*(s),*(e),n)}

/* procedure parameter types for -A and -C++ */

#ifdef __cplusplus

typedef logical (*L_fp)(...);

#else

typedef logical (*L_fp)();

#endif

static float spow_ui(float x, integer n) {

float pow=1.0; unsigned long int u;

if(n != 0) {

if(n < 0) n = -n, x = 1/x;

for(u = n; ; ) {

if(u & 01) pow *= x;

if(u >>= 1) x *= x;

else break;

}

}

return pow;

}

static double dpow_ui(double x, integer n) {

double pow=1.0; unsigned long int u;

if(n != 0) {

if(n < 0) n = -n, x = 1/x;

for(u = n; ; ) {

if(u & 01) pow *= x;

if(u >>= 1) x *= x;

else break;

}

}

return pow;

}

#ifdef _MSC_VER

static _Fcomplex cpow_ui(complex x, integer n) {

complex pow={1.0,0.0}; unsigned long int u;

if(n != 0) {

if(n < 0) n = -n, x.r = 1/x.r, x.i=1/x.i;

for(u = n; ; ) {

if(u & 01) pow.r *= x.r, pow.i *= x.i;

if(u >>= 1) x.r *= x.r, x.i *= x.i;

else break;

}

}

_Fcomplex p={pow.r, pow.i};

return p;

}

#else

static _Complex float cpow_ui(_Complex float x, integer n) {

_Complex float pow=1.0; unsigned long int u;

if(n != 0) {

if(n < 0) n = -n, x = 1/x;

for(u = n; ; ) {

if(u & 01) pow *= x;

if(u >>= 1) x *= x;

else break;

}

}

return pow;

}

#endif

#ifdef _MSC_VER

static _Dcomplex zpow_ui(_Dcomplex x, integer n) {

_Dcomplex pow={1.0,0.0}; unsigned long int u;

if(n != 0) {

if(n < 0) n = -n, x._Val[0] = 1/x._Val[0], x._Val[1] =1/x._Val[1];

for(u = n; ; ) {

if(u & 01) pow._Val[0] *= x._Val[0], pow._Val[1] *= x._Val[1];

if(u >>= 1) x._Val[0] *= x._Val[0], x._Val[1] *= x._Val[1];

else break;

}

}

_Dcomplex p = {pow._Val[0], pow._Val[1]};

return p;

}

#else

static _Complex double zpow_ui(_Complex double x, integer n) {

_Complex double pow=1.0; unsigned long int u;

if(n != 0) {

if(n < 0) n = -n, x = 1/x;

for(u = n; ; ) {

if(u & 01) pow *= x;

if(u >>= 1) x *= x;

else break;

}

}

return pow;

}

#endif

static integer pow_ii(integer x, integer n) {

integer pow; unsigned long int u;

if (n <= 0) {

if (n == 0 || x == 1) pow = 1;

else if (x != -1) pow = x == 0 ? 1/x : 0;

else n = -n;

}

if ((n > 0) || !(n == 0 || x == 1 || x != -1)) {

u = n;

for(pow = 1; ; ) {

if(u & 01) pow *= x;

if(u >>= 1) x *= x;

else break;

}

}

return pow;

}

static integer dmaxloc_(double *w, integer s, integer e, integer *n)

{

double m; integer i, mi;

for(m=w[s-1], mi=s, i=s+1; i<=e; i++)

if (w[i-1]>m) mi=i ,m=w[i-1];

return mi-s+1;

}

static integer smaxloc_(float *w, integer s, integer e, integer *n)

{

float m; integer i, mi;

for(m=w[s-1], mi=s, i=s+1; i<=e; i++)

if (w[i-1]>m) mi=i ,m=w[i-1];

return mi-s+1;

}

static inline void cdotc_(complex *z, integer *n_, complex *x, integer *incx_, complex *y, integer *incy_) {

integer n = *n_, incx = *incx_, incy = *incy_, i;

#ifdef _MSC_VER

_Fcomplex zdotc = {0.0, 0.0};

if (incx == 1 && incy == 1) {

for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */

zdotc._Val[0] += conjf(Cf(&x[i]))._Val[0] * Cf(&y[i])._Val[0];

zdotc._Val[1] += conjf(Cf(&x[i]))._Val[1] * Cf(&y[i])._Val[1];

}

} else {

for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */

zdotc._Val[0] += conjf(Cf(&x[i*incx]))._Val[0] * Cf(&y[i*incy])._Val[0];

zdotc._Val[1] += conjf(Cf(&x[i*incx]))._Val[1] * Cf(&y[i*incy])._Val[1];

}

}

pCf(z) = zdotc;

}

#else

_Complex float zdotc = 0.0;

if (incx == 1 && incy == 1) {

for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */

zdotc += conjf(Cf(&x[i])) * Cf(&y[i]);

}

} else {

for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */

zdotc += conjf(Cf(&x[i*incx])) * Cf(&y[i*incy]);

}

}

pCf(z) = zdotc;

}

#endif

static inline void zdotc_(doublecomplex *z, integer *n_, doublecomplex *x, integer *incx_, doublecomplex *y, integer *incy_) {

integer n = *n_, incx = *incx_, incy = *incy_, i;

#ifdef _MSC_VER

_Dcomplex zdotc = {0.0, 0.0};

if (incx == 1 && incy == 1) {

for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */

zdotc._Val[0] += conj(Cd(&x[i]))._Val[0] * Cd(&y[i])._Val[0];

zdotc._Val[1] += conj(Cd(&x[i]))._Val[1] * Cd(&y[i])._Val[1];

}

} else {

for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */

zdotc._Val[0] += conj(Cd(&x[i*incx]))._Val[0] * Cd(&y[i*incy])._Val[0];

zdotc._Val[1] += conj(Cd(&x[i*incx]))._Val[1] * Cd(&y[i*incy])._Val[1];

}

}

pCd(z) = zdotc;

}

#else

_Complex double zdotc = 0.0;

if (incx == 1 && incy == 1) {

for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */

zdotc += conj(Cd(&x[i])) * Cd(&y[i]);

}

} else {

for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */

zdotc += conj(Cd(&x[i*incx])) * Cd(&y[i*incy]);

}

}

pCd(z) = zdotc;

}

#endif

static inline void cdotu_(complex *z, integer *n_, complex *x, integer *incx_, complex *y, integer *incy_) {

integer n = *n_, incx = *incx_, incy = *incy_, i;

#ifdef _MSC_VER

_Fcomplex zdotc = {0.0, 0.0};

if (incx == 1 && incy == 1) {

for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */

zdotc._Val[0] += Cf(&x[i])._Val[0] * Cf(&y[i])._Val[0];

zdotc._Val[1] += Cf(&x[i])._Val[1] * Cf(&y[i])._Val[1];

}

} else {

for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */

zdotc._Val[0] += Cf(&x[i*incx])._Val[0] * Cf(&y[i*incy])._Val[0];

zdotc._Val[1] += Cf(&x[i*incx])._Val[1] * Cf(&y[i*incy])._Val[1];

}

}

pCf(z) = zdotc;

}

#else

_Complex float zdotc = 0.0;

if (incx == 1 && incy == 1) {

for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */

zdotc += Cf(&x[i]) * Cf(&y[i]);

}

} else {

for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */

zdotc += Cf(&x[i*incx]) * Cf(&y[i*incy]);

}

}

pCf(z) = zdotc;

}

#endif

static inline void zdotu_(doublecomplex *z, integer *n_, doublecomplex *x, integer *incx_, doublecomplex *y, integer *incy_) {

integer n = *n_, incx = *incx_, incy = *incy_, i;

#ifdef _MSC_VER

_Dcomplex zdotc = {0.0, 0.0};

if (incx == 1 && incy == 1) {

for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */

zdotc._Val[0] += Cd(&x[i])._Val[0] * Cd(&y[i])._Val[0];

zdotc._Val[1] += Cd(&x[i])._Val[1] * Cd(&y[i])._Val[1];

}

} else {

for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */

zdotc._Val[0] += Cd(&x[i*incx])._Val[0] * Cd(&y[i*incy])._Val[0];

zdotc._Val[1] += Cd(&x[i*incx])._Val[1] * Cd(&y[i*incy])._Val[1];

}

}

pCd(z) = zdotc;

}

#else

_Complex double zdotc = 0.0;

if (incx == 1 && incy == 1) {

for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */

zdotc += Cd(&x[i]) * Cd(&y[i]);

}

} else {

for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */

zdotc += Cd(&x[i*incx]) * Cd(&y[i*incy]);

}

}

pCd(z) = zdotc;

}

#endif

/* -- translated by f2c (version 20000121).

You must link the resulting object file with the libraries:

-lf2c -lm (in that order)

*/

/* -- translated by f2c (version 20000121).

You must link the resulting object file with the libraries:

-lf2c -lm (in that order)

*/

/* -- translated by f2c (version 20000121).

You must link the resulting object file with the libraries:

-lf2c -lm (in that order)

*/

/* Table of constant values */

static complex c_b1 = {1.f,0.f};

static integer c__1 = 1;

/* > \brief \b CGBTF2 computes the LU factorization of a general band matrix using the unblocked version of th

e algorithm. */

/* =========== DOCUMENTATION =========== */

/* Online html documentation available at */

/* http://www.netlib.org/lapack/explore-html/ */

/* > \htmlonly */

/* > Download CGBTF2 + dependencies */

/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/cgbtf2.

f"> */

/* > [TGZ]</a> */

/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/cgbtf2.

f"> */

/* > [ZIP]</a> */

/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/cgbtf2.

f"> */

/* > [TXT]</a> */

/* > \endhtmlonly */

/* Definition: */

/* =========== */

/* SUBROUTINE CGBTF2( M, N, KL, KU, AB, LDAB, IPIV, INFO ) */

/* INTEGER INFO, KL, KU, LDAB, M, N */

/* INTEGER IPIV( * ) */

/* COMPLEX AB( LDAB, * ) */

/* > \par Purpose: */

/* ============= */

/* > */

/* > \verbatim */

/* > */

/* > CGBTF2 computes an LU factorization of a complex m-by-n band matrix */

/* > A using partial pivoting with row interchanges. */

/* > */

/* > This is the unblocked version of the algorithm, calling Level 2 BLAS. */

/* > \endverbatim */

/* Arguments: */

/* ========== */

/* > \param[in] M */

/* > \verbatim */

/* > M is INTEGER */

/* > The number of rows of the matrix A. M >= 0. */

/* > \endverbatim */

/* > */

/* > \param[in] N */

/* > \verbatim */

/* > N is INTEGER */

/* > The number of columns of the matrix A. N >= 0. */

/* > \endverbatim */

/* > */

/* > \param[in] KL */

/* > \verbatim */

/* > KL is INTEGER */

/* > The number of subdiagonals within the band of A. KL >= 0. */

/* > \endverbatim */

/* > */

/* > \param[in] KU */

/* > \verbatim */

/* > KU is INTEGER */

/* > The number of superdiagonals within the band of A. KU >= 0. */

/* > \endverbatim */

/* > */

/* > \param[in,out] AB */

/* > \verbatim */

/* > AB is COMPLEX array, dimension (LDAB,N) */

/* > On entry, the matrix A in band storage, in rows KL+1 to */

/* > 2*KL+KU+1; rows 1 to KL of the array need not be set. */

/* > The j-th column of A is stored in the j-th column of the */

/* > array AB as follows: */

/* > AB(kl+ku+1+i-j,j) = A(i,j) for f2cmax(1,j-ku)<=i<=f2cmin(m,j+kl) */

/* > */

/* > On exit, details of the factorization: U is stored as an */

/* > upper triangular band matrix with KL+KU superdiagonals in */

/* > rows 1 to KL+KU+1, and the multipliers used during the */

/* > factorization are stored in rows KL+KU+2 to 2*KL+KU+1. */

/* > See below for further details. */

/* > \endverbatim */

/* > */

/* > \param[in] LDAB */

/* > \verbatim */

/* > LDAB is INTEGER */

/* > The leading dimension of the array AB. LDAB >= 2*KL+KU+1. */

/* > \endverbatim */

/* > */

/* > \param[out] IPIV */

/* > \verbatim */

/* > IPIV is INTEGER array, dimension (f2cmin(M,N)) */

/* > The pivot indices; for 1 <= i <= f2cmin(M,N), row i of the */

/* > matrix was interchanged with row IPIV(i). */

/* > \endverbatim */

/* > */

/* > \param[out] INFO */

/* > \verbatim */

/* > INFO is INTEGER */

/* > = 0: successful exit */

/* > < 0: if INFO = -i, the i-th argument had an illegal value */

/* > > 0: if INFO = +i, U(i,i) is exactly zero. The factorization */

/* > has been completed, but the factor U is exactly */

/* > singular, and division by zero will occur if it is used */

/* > to solve a system of equations. */

/* > \endverbatim */

/* Authors: */

/* ======== */

/* > \author Univ. of Tennessee */

/* > \author Univ. of California Berkeley */

/* > \author Univ. of Colorado Denver */

/* > \author NAG Ltd. */

/* > \date December 2016 */

/* > \ingroup complexGBcomputational */

/* > \par Further Details: */

/* ===================== */

/* > */

/* > \verbatim */

/* > */

/* > The band storage scheme is illustrated by the following example, when */

/* > M = N = 6, KL = 2, KU = 1: */

/* > */

/* > On entry: On exit: */

/* > */

/* > * * * + + + * * * u14 u25 u36 */

/* > * * + + + + * * u13 u24 u35 u46 */

/* > * a12 a23 a34 a45 a56 * u12 u23 u34 u45 u56 */

/* > a11 a22 a33 a44 a55 a66 u11 u22 u33 u44 u55 u66 */

/* > a21 a32 a43 a54 a65 * m21 m32 m43 m54 m65 * */

/* > a31 a42 a53 a64 * * m31 m42 m53 m64 * * */

/* > */

/* > Array elements marked * are not used by the routine; elements marked */

/* > + need not be set on entry, but are required by the routine to store */

/* > elements of U, because of fill-in resulting from the row */

/* > interchanges. */

/* > \endverbatim */

/* > */

/* ===================================================================== */

/* Subroutine */ void cgbtf2_(integer *m, integer *n, integer *kl, integer *ku,

complex *ab, integer *ldab, integer *ipiv, integer *info)

{

/* System generated locals */

integer ab_dim1, ab_offset, i__1, i__2, i__3, i__4;

complex q__1;

/* Local variables */

integer i__, j;

extern /* Subroutine */ void cscal_(integer *, complex *, complex *,

integer *), cgeru_(integer *, integer *, complex *, complex *,

integer *, complex *, integer *, complex *, integer *), cswap_(

integer *, complex *, integer *, complex *, integer *);

integer km, jp, ju, kv;

extern integer icamax_(integer *, complex *, integer *);

extern /* Subroutine */ int xerbla_(char *, integer *, ftnlen);

/* -- LAPACK computational routine (version 3.7.0) -- */

/* -- LAPACK is a software package provided by Univ. of Tennessee, -- */

/* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */

/* December 2016 */

/* ===================================================================== */

/* KV is the number of superdiagonals in the factor U, allowing for */

/* fill-in. */

/* Parameter adjustments */

ab_dim1 = *ldab;

ab_offset = 1 + ab_dim1 * 1;

ab -= ab_offset;

--ipiv;

/* Function Body */

kv = *ku + *kl;

/* Test the input parameters. */

*info = 0;

if (*m < 0) {

*info = -1;

} else if (*n < 0) {

*info = -2;

} else if (*kl < 0) {

*info = -3;

} else if (*ku < 0) {

*info = -4;

} else if (*ldab < *kl + kv + 1) {

*info = -6;

}

if (*info != 0) {

i__1 = -(*info);

xerbla_("CGBTF2", &i__1, (ftnlen)6);

return;

}

/* Quick return if possible */

if (*m == 0 || *n == 0) {

return;

}

/* Gaussian elimination with partial pivoting */

/* Set fill-in elements in columns KU+2 to KV to zero. */

i__1 = f2cmin(kv,*n);

for (j = *ku + 2; j <= i__1; ++j) {

i__2 = *kl;

for (i__ = kv - j + 2; i__ <= i__2; ++i__) {

i__3 = i__ + j * ab_dim1;

ab[i__3].r = 0.f, ab[i__3].i = 0.f;

/* L10: */

}

/* L20: */

}

/* JU is the index of the last column affected by the current stage */

/* of the factorization. */

ju = 1;

i__1 = f2cmin(*m,*n);

for (j = 1; j <= i__1; ++j) {

/* Set fill-in elements in column J+KV to zero. */

if (j + kv <= *n) {

i__2 = *kl;

for (i__ = 1; i__ <= i__2; ++i__) {

i__3 = i__ + (j + kv) * ab_dim1;

ab[i__3].r = 0.f, ab[i__3].i = 0.f;

/* L30: */

}

}

/* Find pivot and test for singularity. KM is the number of */

/* subdiagonal elements in the current column. */

/* Computing MIN */

i__2 = *kl, i__3 = *m - j;

km = f2cmin(i__2,i__3);

i__2 = km + 1;

jp = icamax_(&i__2, &ab[kv + 1 + j * ab_dim1], &c__1);

ipiv[j] = jp + j - 1;

i__2 = kv + jp + j * ab_dim1;

if (ab[i__2].r != 0.f || ab[i__2].i != 0.f) {

/* Computing MAX */

/* Computing MIN */

i__4 = j + *ku + jp - 1;

i__2 = ju, i__3 = f2cmin(i__4,*n);

ju = f2cmax(i__2,i__3);

/* Apply interchange to columns J to JU. */

if (jp != 1) {

i__2 = ju - j + 1;

i__3 = *ldab - 1;

i__4 = *ldab - 1;

cswap_(&i__2, &ab[kv + jp + j * ab_dim1], &i__3, &ab[kv + 1 +

j * ab_dim1], &i__4);

}

if (km > 0) {

/* Compute multipliers. */

c_div(&q__1, &c_b1, &ab[kv + 1 + j * ab_dim1]);

cscal_(&km, &q__1, &ab[kv + 2 + j * ab_dim1], &c__1);

/* Update trailing submatrix within the band. */

if (ju > j) {

i__2 = ju - j;

q__1.r = -1.f, q__1.i = 0.f;

i__3 = *ldab - 1;

i__4 = *ldab - 1;

cgeru_(&km, &i__2, &q__1, &ab[kv + 2 + j * ab_dim1], &

c__1, &ab[kv + (j + 1) * ab_dim1], &i__3, &ab[kv

+ 1 + (j + 1) * ab_dim1], &i__4);

}

}

} else {

/* If pivot is zero, set INFO to the index of the pivot */

/* unless a zero pivot has already been found. */

if (*info == 0) {

*info = j;

}

}

/* L40: */

}

return;

/* End of CGBTF2 */

} /* cgbtf2_ */