absolute(_:result:)

Declaration

static func absolute<V>(_ vector: DSPDoubleSplitComplex, result: inout V) where V : AccelerateMutableBuffer, V.Element == Double

Parameters

• vector:

  The source vector.

• result:

  On output, the absolute values of the elements in the source vector.

Discussion

This function returns the square roots of the sum of the squares of the real and imaginary parts of each complex element.

For example, the following code calculates the absolute values of four complex numbers:

    let n = 4
    
    let reals = UnsafeMutableBufferPointer<Double>.allocate(capacity: n)
    _ = reals.initialize(from: [ -3, -6, 5, 9 ])
    
    let imaginaries = UnsafeMutableBufferPointer<Double>.allocate(capacity: n)
    _ = imaginaries.initialize(from: [ 4, -8, -12, 12 ])
    
    let values = DSPDoubleSplitComplex(realp: reals.baseAddress!,
                                       imagp: imaginaries.baseAddress!)
    
    
    let absoluteValues = [Double](unsafeUninitializedCapacity: n) {
        buffer, initializedCount in
        
        vDSP.absolute(values, result: &buffer)
        
        initializedCount = n
    }
    
    // Prints "[5.0, 10.0, 13.0, 15.0]".
    print(absoluteValues)

See Also

Complex vector absolute functions

• absolute(_:result:)