ZeroDivisionError at lag_ratio.

[Natsurii]

Hello! I was trying to animate this on jupyter notebook. Which basically fine when I run it. It renders correctly.

%%manim -ql -v WARNING RamRep
def codeAnim(codestring) -> Code:
  return Code(
            code=codestring,
            tab_width=4,
            language="C++",
            font="Monospace"
        ).scale(0.8).shift(1.75 * UP)


class RamRep(Scene):
  def construct(self):
#  ===============   SLIDE 1     ================
    l1 = Line(start = [-5,-3,0], end = [5,-3,0])
    l2 = Line(start = [-5,-2,0], end = [5,-2,0])
    l3 = Line(start = [-5,-2.5,0], end = [5,-2.5,0])
    l4 = Line(start = [-4,-2,0], end = [-4,-3,0])
    ram_title = Text("RAM Module Representation").scale(0.3).shift(3.50 * LEFT, 1.75 * DOWN)
    val_row = Text("value").scale(0.3).shift(4.5 * LEFT, 2.25 * DOWN)
    add_row = Text("address").scale(0.3).shift(4.5 * LEFT, 2.75 * DOWN)

    free_space = Text("Free space").scale(0.3).shift(0 * LEFT, 2.25 * DOWN)
    #self.add(l1,l2,l3,l4,ram_title,val_row,free_space)
    init_code = codeAnim("""
#include <iostream>
using namespace std;

int main(){
  return 0;
}
""")
    ram = VGroup()
    ram.add(l1,l2,l3,l4)
    self.play(
        Create(ram),
        Write(ram_title),
        Write(val_row),
        Write(add_row),
        Write(free_space),
        Write(init_code),
        lag_ratio=0.1
    )

    subtitle1 = Text("Initialization of Code").scale(0.7).shift(1 * DOWN)
    self.play(Write(subtitle1))
    self.wait(5)
    self.remove(subtitle1)

#  ===============   SLIDE 2     ================

    int_code = codeAnim("""
#include <iostream>
using namespace std;

int main(){
  int dummy = 11;
  


  return 0;
}
""")
    val_int = Text("11").scale(0.3).shift(3.5 * RIGHT, 2.25 * DOWN)
    add_int = Text("0x1F24").scale(0.3).shift(3.5 * RIGHT, 2.75 * DOWN)
    int_l1 = Line(start = [3,-2,0], end = [3,-3,0])
    int_l2 = Line(start = [4,-2,0], end = [4,-3,0])

    self.play(
        ReplacementTransform(init_code,int_code),
        Create(int_l1),
        Create(int_l2),
        Write(val_int),
        Write(add_int),
        lag_ratio=0.1

    )
    subtitle2 = Text("Declaring an integer variable.").scale(0.7).shift(1 * DOWN)
    self.play(Write(subtitle2))
    self.wait(5)
    self.remove(subtitle2)

But when I add this part,

#  ===============   SLIDE 3     ================

    ptr_code = codeAnim("""
#include <iostream>
using namespace std;

int main(){
  int dummy = 11;
  int *dummyptr;


  return 0;
}
""")
    val_ptr = Text("  ").scale(0.3).shift(1.5 * LEFT, 2.25 * DOWN)
    add_ptr = Text("0x0D66").scale(0.3).shift(1.5 * LEFT, 2.75 * DOWN)
    ptr_l1 = Line(start = [-1,-2,0], end = [-1,-3,0])
    ptr_l2 = Line(start = [1,-2,0], end = [1,-3,0])

    self.play(
        ReplacementTransform(int_code,ptr_code),
        Create(ptr_l1),
        Create(ptr_l2),
        Write(val_ptr),
        Write(add_ptr)
    )
    subtitle3 = Text("Declaring the pointer and allocating to the memory.").scale(0.7).shift(1 * DOWN)
    self.play(Write(subtitle3))
    self.wait(3)
    self.remove(subtitle3)

It throws this ZeroDivisionError.

---------------------------------------------------------------------------
ZeroDivisionError                         Traceback (most recent call last)
<ipython-input-6-8d82da7ab79b> in <module>
----> 1 get_ipython().run_cell_magic('manim', '-ql -v WARNING RamRep', 'def codeAnim(codestring) -> Code:\n  return Code(\n...

6 frames
/usr/local/lib/python3.7/dist-packages/IPython/core/interactiveshell.py in run_cell_magic(self, magic_name, line, cell)
   2404             with self.builtin_trap:
   2405                 args = (magic_arg_s, cell)
-> 2406                 result = fn(*args, **kwargs)
   2407             return result
   2408 

/usr/local/lib/python3.7/dist-packages/decorator.py in fun(*args, **kw)
    230             if not kwsyntax:
    231                 args, kw = fix(args, kw, sig)
--> 232             return caller(func, *(extras + args), **kw)
    233     fun.__name__ = func.__name__
    234     fun.__doc__ = func.__doc__

/usr/local/lib/python3.7/dist-packages/IPython/core/magic.py in <lambda>(f, *a, **k)
    185     # but it's overkill for just that one bit of state.
    186     def magic_deco(arg):
--> 187         call = lambda f, *a, **k: f(*a, **k)
    188 
    189         if callable(arg):

/usr/local/lib/python3.7/dist-packages/manim/utils/ipython_magic.py in manim(self, line, cell, local_ns)
    134                     SceneClass = local_ns[config["scene_names"][0]]
    135                     scene = SceneClass(renderer=renderer)
--> 136                     scene.render()
    137                 finally:
    138                     # Shader cache becomes invalid as the context is destroyed

/usr/local/lib/python3.7/dist-packages/manim/scene/scene.py in render(self, preview)
    214         self.setup()
    215         try:
--> 216             self.construct()
    217         except EndSceneEarlyException:
    218             pass

<string> in construct(self)

/usr/local/lib/python3.7/dist-packages/manim/animation/creation.py in __init__(self, vmobject, rate_func, reverse, **kwargs)
    304             vmobject,
    305             run_time,
--> 306             lag_ratio,
    307         )
    308         self.reverse = reverse

/usr/local/lib/python3.7/dist-packages/manim/animation/creation.py in _set_default_config_from_length(self, vmobject, run_time, lag_ratio)
    328                 run_time = 2
    329         if lag_ratio is None:
--> 330             lag_ratio = min(4.0 / length, 0.2)
    331         return run_time, lag_ratio
    332 

ZeroDivisionError: float division by zero

Any way to fix this? Or maybe this is a bug.
Any response will be greatly appreciated.

Thanks!

[behackl]

The problem is Write(val_ptr), which tells Manim to write a text that consists of no characters. You can try and see what happens if you pass lag_ratio=0 to the Write call, or you simply remove it because it will not do anything anyways.