Can we write combinations (nCr) like `\frac{}{}` ?

[Alamin-H-M]

Hey, I'm using Manim for probability/statistics videos. To write combination notation right now I have to do this:

from manim import *

class Sample_slide(Scene):
    def construct(self):
        problem = MathTex(r"P(x) = {}^{n}C_{x}\,  p^x q^{n-x}")
        self.play(Write(problem))
        self.wait()

The {}^{x+r}C_{r}\, part is really messy just for a single symbol. It would be much cleaner if Manim had a built-in command like \ncr{}{} so I could just write:

MathTex(r"P(x) = \ncr{x+r}{r} p^x q^{n-x}")

like how \frac{}{} works. Would it be possible to add this to Manim's default LaTeX template?

Thanks

---

[uwezi]

I am not familiar with this particular notation, but you can of course always define your own macros i LaTeX

class prob(Scene):
    def construct(self):
        ttmpl = TexTemplate()
        ttmpl.add_to_preamble(r"\newcommand{\ncr}[2]{{}^{#1}{#2}}")
        MathTex.set_default(tex_template=ttmpl)
        problem = MathTex(r"P(x) = \ncr{n}{C_{x}}\, p^x q^{n-x}")
        self.add(problem)

[philipp-harland]

Would it be possible to add this to Manim's default LaTeX template?

Possible? Yeah, I think. But I have a gut feeling it would sort of disrupt the flow of the rest of the codebase.

[uwezi]

It seems to be a very limited use case - there are gazillions of specialized packages to extend LaTeX. There is no way that all of these should be included into Manim. Just add what you need yourself for your projects...