`get_parts_by_tex` return wrong SVG element

[Sourish07]

Describe the bug

When I try to grab an element from a fraction with get_parts_by_tex, there's an off by one error

Code:

from manimlib import *

class Test(Scene):
    def construct(self):
        s = Tex(r"\frac{ 1 }{ 2 }")
        s.get_parts_by_tex(r"1").set_color(GREEN)
        self.add(s)

Wrong display or Error traceback:

Additional context

I think this is because there's a mismatch between the order of the Tex commands vs the order of the svg elements.

• tex_commands = ["\\frac", "1", "2"]
• get_parts_by_tex(1) points to idx value 1 (because "1" is second element in tex_commands)
• svg_map = ["1", "/", "2"] (idx value 1 returns the "/")

We need a way to tell manim that when it sees \frac, to make sure the items in the numerator come before the "/"

[mathsvisualization]

🐛 Bug: get_parts_by_tex misbehaves with \frac in Tex

Problem

When trying to use get_parts_by_tex("1") or get_parts_by_tex("2") on a Tex expression containing a \frac, ManimGL may color the wrong part, often the / divider instead of the actual numerator or denominator.

❌ Buggy Code

from manimlib import *

class Test(Scene):
    def construct(self):
        s = Tex(r"\frac{ 1 }{ 2 }")
        s.get_parts_by_tex("1").set_color(GREEN)
        self.add(s)

---

Why this work?

Using isolate=["1", "2"] ensures Manim creates separate SVG submobjects for "1" and "2",
making them reliably accessible using get_parts_by_tex.

---

Solution

from manimlib import *

class testGetPartsByTex(InteractiveScene):
    def construct(self):
        txt = Tex(R"\frac{1}{2}", isolate=["1", "2"])
        txt.get_parts_by_tex("1").set_color(RED)
        self.add(txt)

output