# Objective
The parameter names for `bevy::math::ops::atan2` are labelled such that
`x` is the first argument and `y` is the second argument, but it passes
those arguments directly to
[`f32::atan2`](https://doc.rust-lang.org/stable/std/primitive.f32.html#method.atan2),
whose parameters are expected to be `(y, x)`. This PR changes the
parameter names in the bevy documentation to use the correct order for
the operation being performed. You can verify this by doing:
```rust
fn main() {
let x = 3.0;
let y = 4.0;
let angle = bevy::math::ops::atan2(x, y);
// standard polar coordinates formula
dbg!(5.0 * angle.cos(), 5.0 * angle.sin());
}
```
This will print `(4.0, 3.0)`, which has flipped `x` and `y`. The problem
is that the `atan2` function to calculate the angle was really expecting
`(y, x)`, not `(x, y)`.
## Solution
I flipped the parameter names for `bevy::math::ops::atan2` and updated
the documentation. I also removed references to `self` and `other` from
the documentation which seemed to be copied from the `f32::atan2`
documentation.
## Testing
Not really needed, you can compare the `f32::atan2` docs to the
`bevy::math::ops::atan2` docs to see the problem is obvious. If a test
is required I could add a short one.
## Migration Guide
I'm not sure if this counts as a breaking change, since the
implementation clearly meant to use `f32::atan2` directly, so it was
really just the parameter names that were wrong.
c928ca1e18