How to convert degrees to radians

Paul Hudson    February 13th 2018    @twostraws

Most users think about angles in terms of degrees from 0 to 360, but internally most of iOS works in radians so you’ll need to do some conversion. The equation to convert between the two is simple enough: multiply the number by Pi, then divide the result by 180.

To make things easier, drop in this function:

func deg2rad(_ number: Double) -> Double {
    return number * .pi / 180
}

You can now use deg2rad(90) to find 90 degrees in radians.

Available from iOS 8.0

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