void lpf_btran(LPF *lpf, double x[])
{ int m0 = lpf->m0;
int m = lpf->m;
int n = lpf->n;
int *P_row = lpf->P_row;
int *Q_row = lpf->Q_row;
double *fg = lpf->work1;
double *f = fg;
double *g = fg + m0;
int i, ii;
#if GLPLPF_DEBUG
double *b;
#endif
if (!lpf->valid)
xfault("lpf_btran: the factorization is not valid\n");
xassert(0 <= m && m <= m0 + n);
#if GLPLPF_DEBUG
/* save the right-hand side vector */
b = xcalloc(1+m, sizeof(double));
for (i = 1; i <= m; i++) b[i] = x[i];
#endif
/* (f g) := Q * (b 0) */
for (i = 1; i <= m0 + n; i++)
fg[i] = ((ii = Q_row[i]) <= m ? x[ii] : 0.0);
/* f1 := inv(U'0) * f */
#if 0 /* 06/VI-2013 */
luf_v_solve(lpf->luf, 1, f);
#else
{ double *work = lpf->lufint->sgf->work;
luf_vt_solve(lpf->lufint->luf, f, work);
memcpy(&f[1], &work[1], m0 * sizeof(double));
}
#endif
/* g1 := inv(C') * (g - R' * f1) */
rt_prod(lpf, g, -1.0, f);
scf_solve_it(lpf->scf, 1, g);
/* g2 := g1 */
g = g;
/* f2 := inv(L'0) * (f1 - S' * g2) */
st_prod(lpf, f, -1.0, g);
#if 0 /* 06/VI-2013 */
luf_f_solve(lpf->luf, 1, f);
#else
luf_ft_solve(lpf->lufint->luf, f);
#endif
/* (x y) := P * (f2 g2) */
for (i = 1; i <= m; i++)
x[i] = fg[P_row[i]];
#if GLPLPF_DEBUG
/* check relative error in solution */
check_error(lpf, 1, x, b);
xfree(b);
#endif
return;
}
void scf_r0_solve(SCF *scf, int tr, double x[/*1+n0*/])
{ switch (scf->type)
{ case 1:
/* A0 = F0 * V0, so R0 = F0 */
if (!tr)
luf_f_solve(scf->a0.luf, x);
else
luf_ft_solve(scf->a0.luf, x);
break;
case 2:
/* A0 = I * A0, so R0 = I */
break;
default:
xassert(scf != scf);
}
return;
}
