def measure_bz(curve, s0, s1, bz): bz_arclen = tocubic.bz_arclength_rk4(bz) if bz_arclen == 0: return 1e9 arclen_scale = (s1 - s0) / bz_arclen def th_fn(s): return curve.th(s0 + arclen_scale * s, s == 0) return tocubic.measure_bz_rk4(bz, bz_arclen, th_fn)
def measure_bz(curve, s0, s1, bz): bz_arclen = tocubic.bz_arclength_rk4(bz) if bz_arclen == 0: return 1e9 arclen_scale = (s1 - s0) / bz_arclen def th_fn(s): return curve.th(s0 + arclen_scale * s, s == 0) return tocubic.measure_bz_rk4(bz, bz_arclen, th_fn)
def measure_bz_cloth(seg, bz, n = 100):
bz_arclen = tocubic.bz_arclength_rk4(bz)
arclen_ratio = seg.arclen / bz_arclen
dbz = tocubic.bz_deriv(bz)
def measure_derivs(x, ys):
dx, dy = tocubic.bz_eval(dbz, x)
ds = hypot(dx, dy)
s = ys[0] * arclen_ratio
dscore = ds * (tocubic.mod_2pi(atan2(dy, dx) - seg.th(s)) ** 2)
#print s, atan2(dy, dx), seg.th(s)
return [ds, dscore]
dt = 1./n
t = 0
ys = [0, 0]
for i in range(n):
dydx = measure_derivs(t, ys)
tocubic.rk4(ys, dydx, t, dt, measure_derivs)
t += dt
return ys[1]
def measure_bz_cloth(seg, bz, n=100):
bz_arclen = tocubic.bz_arclength_rk4(bz)
arclen_ratio = seg.arclen / bz_arclen
dbz = tocubic.bz_deriv(bz)
def measure_derivs(x, ys):
dx, dy = tocubic.bz_eval(dbz, x)
ds = hypot(dx, dy)
s = ys[0] * arclen_ratio
dscore = ds * (tocubic.mod_2pi(atan2(dy, dx) - seg.th(s))**2)
#print s, atan2(dy, dx), seg.th(s)
return [ds, dscore]
dt = 1. / n
t = 0
ys = [0, 0]
for i in range(n):
dydx = measure_derivs(t, ys)
tocubic.rk4(ys, dydx, t, dt, measure_derivs)
t += dt
return ys[1]
