Jeff Ford's profile - activity

I think you're right. I've been able to use the tachyon viewer, but I'm trying to animate a series of nested tori, and was hoping to control tachyon directly. I've got the animation without it, but it would be nice to change the view and lighting.

It's happened to me as well.

I'm trying to figure out how to render a torus using Tachyon. The problem is that a solid torus requires a 2 variable parametric equation, and it seems Tachyon only likes to use single variable parametric equations. Is there a way around this?

I incorporated the suggestions and worked the bounds into two different loops. Seems to have fixed it.

u,v = var('u,v')

def is_even(n):
    return n%2 == 0

def c(n):
    return 2/3*(4^(n+1)-4)

def torus(n,u,v):
    if is_even(n):
        return [(2*4**n + 4**n*cos(u))*cos(v), (2*4**n + 4**n*cos(u))*sin(v)+c(n), 4**n*sin(u)]
    else:
        return [4**n*sin(u), (2*4**n + 4**n*cos(u))*sin(v)+c(n),  (2*4**n + 4**n*cos(u))*cos(v)]
T0 = []
for i in srange(0,2*pi+0.1, 0.1):
    T0.append(parametric_plot3d(torus(0,u,v), (u,0,2*pi),(v,i, i+0.1), aspect_ratio=1, frame=False, axes=False))

T = []    
for i in range(len(T0)):
    T.append(sum(T0[j] for j in range(i)))

a = animate(T)
a.show()

I'm trying to animate a series of increasing, nested tori. I'm testing the code for the first one, but the aspect ratio isn't behaving, and axes are showing up. I've tried messing with figsize, to no avail. Suggestions?

u,v = var('u,v')
def is_even(n):
    return n%2 == 0

def c(n):
   return 2/3*(4^(n+1)-4)

def torus(n,u,v):
   if is_even(n):
        return [(2*4**n + 4**n*cos(u))*cos(v), (2*4**n + 4**n*cos(u))*sin(v) + c(n), 4**n*sin(u)]
    else:
        return [4**n*sin(u), (2*4**n + 4**n*cos(u))*sin(v) + c(n),  (2*4**n + 4**n*cos(u))*cos(v)]

T = []

for i in range(10):
    T.append(parametric_plot3d(torus(0,u,v), (u,0,(i+1)*2*pi/9), (v,0,(i+1)*2*pi/9), axes="false"))

a = animate(T)
a.show()

It does seem to work in a local copy of Sage, but not in the online viewer

I'm using plot_vector_field3d, and I'm not getting any arrows at the ends of the vectors. The documentation seems to indicate this would be automatic. Is there something I'm missing?