Math.atan2 appears to be AWOL

Bugs
1

This morning, because I’m coding a space thing in Kotlin, I opened my Coda Asteroids game and ran it. It crashed looking for math.atan2.

Has atan2 gone missing?

Thanks for all the fish …

R

2

Lua 5.4 deprecated some functions including pow and atan2. You can now use a ^ b for exponents and atan with two parameters replaces atan2 (so just remove the 2)

1 Like
3

@RonJeffries - ran into that one myself. Had me flummoxed for a while. But …

Don’t Panic !!!

4

thanks! I would not have guessed that … the docs need to be updated.

1 Like
5

@RonJeffries yes this was a very sneaky change from the creator of Lua. I’ll make a note about updating the docs. We could also chuck in a math.pow and math.atan2 function for backwards compatibility

6

How about sinh? It seems to also be missing?

7

If you need sinh, cosh, or tanh, you can use this until they’re added to the math functions.

function setup()
    e=math.exp(1)

    print(sinh(1.5))
    print(cosh(1.5))
    print(tanh(1.5))
end

function sinh(x)
    return (e^x-e^-x)/2
end

function cosh(x)
    return (e^x+e^-x)/2
end

function tanh(x)
    return sinh(x)/cosh(x)
end
8

I struggled with this a lot because chatGPT kept putting math.atan2 in calculations it made for me, but then I did a web search on it.

I think math.atan2 still exists, it’s just got a different syntax.

I think math.atan will work like math.atan2 any time you give it two parameters.