void root_pol(double *a, const int odr, Complex * x, const int a_zero,
const double eps, const int itrat)
{
int i, j, k, l;
double th, th1, th2, cm, cmax;
Complex cden, cnum, c1, *deltx;
deltx = cplx_getmem(odr + 1);
if (!a_zero)
for (i = 1; i <= odr; i++)
a[i] /= a[0];
cmax = 0;
for (i = 2; i <= odr; i++) {
cm = odr * rad_root(fabs(a[i]), i);
if (cm > cmax)
cmax = cm;
}
th1 = PI * 2.0 / odr;
th2 = th1 / 4.0;
for (i = 1; i <= odr; i++) {
th = th1 * (i - 1) + th2;
x[i].re = cmax * cos(th);
x[i].im = cmax * sin(th);
}
l = 1;
do {
for (i = 1; i <= odr; i++) {
cden.re = 1.0;
cden.im = 0.0;
cnum.re = 1.0;
cnum.im = 0.0;
c1 = x[i];
for (j = 1; j <= odr; j++) {
cnum = c_math(cnum, multiply, c1);
cnum.re += a[j];
if (j != i)
cden = c_math(cden, multiply, c_math(c1, minus, x[j]));
}
deltx[i] = c_math(cnum, divide, cden);
x[i] = c_math(c1, minus, deltx[i]);
}
k = 1;
while ((k <= odr) && (c_mag(deltx[k++]) <= eps));
l++;
}
while ((l <= itrat) && (k <= odr));
if (l > itrat) {
fprintf(stderr, "root_pol : No convergence!\n");
exit(1);
}
return;
}
int main(int argc, char *argv[])
{
char *s;
int c, k, odr = ORDER, itrat = ITER, form = 0, a_zero = 0;
double *a, *d, eps = EPS;
FILE *fp = stdin;
complex *x;
if ((cmnd = strrchr(argv[0], '/')) == NULL)
cmnd = argv[0];
else
cmnd++;
while (--argc > 0) {
if (*(s = *++argv) == '-') {
c = *++s;
switch (c) {
case 'i':
a_zero = 1;
break;
case 'r':
form |= 1;
break;
case 's':
form |= 2;
break;
case 'e':
if (*++s == '\0') {
s = *++argv;
--argc;
}
eps = atof(s);
break;
case 'm':
if (*++s == '\0') {
s = *++argv;
--argc;
}
odr = atoi(s);
break;
case 'n':
if (*++s == '\0') {
s = *++argv;
--argc;
}
itrat = atoi(s);
break;
default:
usage();
}
} else
fp = getfp(*argv, "rb");
}
a = dgetmem(odr + 1);
odr = freadf(a, sizeof(*a), odr, fp) - 1;
d = dgetmem(odr + 1);
x = cplx_getmem(odr + 1);
for (k = 0; k <= odr; ++k)
d[k] = a[k];
root_pol(d, odr, x, a_zero, eps, itrat);
output_root_pol(x, odr, form);
return (0);
}
