seanlilmateus/LiveTV — comment on commit 1203bc3bfd977049060dfec380be06183fa31529
File: TVFrancaise/AppDelegate.rb line 202
By mattetti:

overlayWindow.frameOrigin = NSMakePoint(NSMinX(fullscreenRect) + ((0.5 * NSWidth(fullscreenRect)) - (0.5 * NSWidth(overlayRect))), 0.15 * NSHeight(fullscreenRect))

You could also pass an array of the 2 coordinates and use a more Ruby like approach to get the coordinates. That said your code is correct.