In the `Calculate` node, it seems the atan2(y,x) function has the x and y switched. Normally, atan2(1,0) should give 0, but it gives 90° (pi/2): it's atan2(0,1) that should give 90°.

I'm using atan2(y,x) to convert cartesian coordinates to polar coordinates, but everyting is offset by 90°. ### No, that's the usual way for

No, that's the usual way for `atan2` to work — https://en.wikipedia.org/wiki/Atan2#Illustrations

As your illustration shows, 0 radians (0°) is at the point x=1, y=0 — but since it's standard for the arguments to `atan2` to be y then x, you would call `atan2(0,1)` to get this value.

Similarly, for π/2 radians (90°), at the point x=0, y=1, you would call `atan2(1,0)`.

I guess they put the arguments as y then x because the arctangent uses the ratio y/x.

### The illustration is from

The image is from https://fr.wikipedia.org/wiki/Atan2 and they use atan2(y,x).

Anyway, depending on the software, it's either atan2(x,y) or atan2(y,x). For this function, it could be simply documented by "atan2(x,y)". Thanks.

### atan2(y,x) is the usual order

atan2(y,x) is the usual order of arguments, as in, the angle to the x axis is atan(y/x).