Note that more variants of this code are found in
Complex>>#arg
Point>>#degrees this one was probably unnecessary,
^self theta radiansToDegrees would be as accurate knowing that
	{Float halfPi radiansToDegrees - 90.
	Float pi radiansToDegrees - 180.
	(Float pi + Float halfPi) radiansToDegrees - 270.
	Float twoPi radiansToDegrees - 360} allSatisfy: [:e | e = 0]
Point>>#bearingToPoint: (same as degrees but shifted 90°
counterclockwise just to have 0° at north - that is upscreen).

2009/10/31  <commits at source.squeak.org>:
> Nicolas Cellier uploaded a new version of Graphics to project The Trunk:
> http://source.squeak.org/trunk/Graphics-nice.86.mcz
>
> ==================== Summary ====================
>
> Name: Graphics-nice.86
> Author: nice
> Time: 31 October 2009, 3:13:31 am
> UUID: 67835c13-ecca-4ff8-8635-e8f15d789607
> Ancestors: Graphics-nice.85
>
> while at arcTan: fix 2 ULP in Float theta
> Note that Float theta is in [0,2*pi[ while arcTan: is in [-pi,pi]
> (0 at 0) theta leads to pi/2 instead of 0 for new version of arcTan: (pi for old version)
> #arcTan: does handle case of negativeZero, #theta doesn't
>
>
> =============== Diff against Graphics-nice.85 ===============
>
> Item was changed:
>  ----- Method: Point>>theta (in category 'polar coordinates') -----
>  theta
>        "Answer the angle the receiver makes with origin in radians. right is 0;
>        down is 90.
>        Corrected the constants from single precision to 64 Bit precision
>        and changed the sends in case of overflow to constants HK 2005-07-23"
>
>        | tan theta |
>        x = 0
>                ifTrue: [y >= 0
> +                               ifTrue: [^ 1.5707963267948966 "90.0 degreesToRadians"]
> -                               ifTrue: [^ 1.570796326794897 "90.0 degreesToRadians"]
>                                ifFalse: [^ 4.71238898038469 "270.0 degreesToRadians"]]
>                ifFalse:
>                        [tan := y asFloat / x asFloat.
>                        theta := tan arcTan.
>                        x >= 0
>                                ifTrue: [y >= 0
>                                                ifTrue: [^theta]
>                                                ifFalse: [^"360.0 degreesToRadians" 6.283185307179586 + theta]]
>                                ifFalse: [^"180.0 degreesToRadians" 3.141592653589793 + theta]]!
>
>
>