void
setup_trange_f(void)
{
// default range is (-pi, pi)
tmin = -M_PI;
tmax = M_PI;
p1 = usr_symbol("trange");
if (!issymbol(p1))
return;
p1 = get_binding(p1);
// must be two element vector
if (!istensor(p1) || p1->u.tensor->ndim != 1 || p1->u.tensor->nelem != 2)
return;
push(p1->u.tensor->elem[0]);
eval();
yyfloat();
eval();
p2 = pop();
push(p1->u.tensor->elem[1]);
eval();
yyfloat();
eval();
p3 = pop();
if (!isnum(p2) || !isnum(p3))
return;
push(p2);
tmin = pop_double();
push(p3);
tmax = pop_double();
if (tmin == tmax)
stop("draw: trange is zero");
}
void
setup_yrange_f(void)
{
// default range is (-10,10)
ymin = -10.0;
ymax = 10.0;
p1 = usr_symbol("yrange");
if (!issymbol(p1))
return;
p1 = get_binding(p1);
// must be two element vector
if (!istensor(p1) || p1->u.tensor->ndim != 1 || p1->u.tensor->nelem != 2)
return;
push(p1->u.tensor->elem[0]);
eval();
yyfloat();
eval();
p2 = pop();
push(p1->u.tensor->elem[1]);
eval();
yyfloat();
eval();
p3 = pop();
if (!isnum(p2) || !isnum(p3))
return;
push(p2);
ymin = pop_double();
push(p3);
ymax = pop_double();
if (ymin == ymax)
stop("draw: yrange is zero");
}
void
eval_f(double t)
{
// These must be volatile or it crashes. (Compiler error?)
// Read it backwards, save_tos is a volatile int, etc.
int volatile save_tos;
U ** volatile save_frame;
save();
save_tos = tos;
save_frame = frame;
draw_flag++;
if (setjmp(draw_stop_return)) {
tos = save_tos;
push(symbol(NIL));
frame = save_frame;
restore();
draw_flag--;
return;
}
push_double(t);
p1 = pop();
set_binding(T, p1);
push(F);
eval();
yyfloat();
eval();
restore();
draw_flag--;
}
void
eval_nroots(void)
{
volatile int h, i, k, n;
push(cadr(p1));
eval();
push(caddr(p1));
eval();
p2 = pop();
if (p2 == symbol(NIL))
guess();
else
push(p2);
p2 = pop();
p1 = pop();
if (!ispoly(p1, p2))
stop("nroots: polynomial?");
// mark the stack
h = tos;
// get the coefficients
push(p1);
push(p2);
n = coeff();
if (n > YMAX)
stop("nroots: degree?");
// convert the coefficients to real and imaginary doubles
for (i = 0; i < n; i++) {
push(stack[h + i]);
real();
yyfloat();
eval();
p1 = pop();
push(stack[h + i]);
imag();
yyfloat();
eval();
p2 = pop();
if (!isdouble(p1) || !isdouble(p2))
stop("nroots: coefficients?");
c[i].r = p1->u.d;
c[i].i = p2->u.d;
}
// pop the coefficients
tos = h;
// n is the number of coefficients, n = deg(p) + 1
monic(n);
for (k = n; k > 1; k--) {
findroot(k);
if (fabs(a.r) < DELTA)
a.r = 0.0;
if (fabs(a.i) < DELTA)
a.i = 0.0;
push_double(a.r);
push_double(a.i);
push(imaginaryunit);
multiply();
add();
divpoly(k);
}
// now make n equal to the number of roots
n = tos - h;
if (n > 1) {
sort_stack(n);
p1 = alloc_tensor(n);
p1->u.tensor->ndim = 1;
p1->u.tensor->dim[0] = n;
for (i = 0; i < n; i++)
p1->u.tensor->elem[i] = stack[h + i];
tos = h;
push(p1);
}
}
