Contents

multiply(addition:addition:result:)

Calculates the double-precision element-wise product of the sums of two pairs of vectors.

Declaration

static func multiply<S, T, U, V>(addition additionAB: (a: S, b: T), addition additionCD: (c: U, d: U), result: inout V) where S : AccelerateBuffer, T : AccelerateBuffer, U : AccelerateBuffer, V : AccelerateMutableBuffer, S.Element == Double, T.Element == Double, U.Element == Double, V.Element == Double

Parameters

  • additionAB:

    A tuple that contains the vectors A and B in E = (A + B) * (C + D).

  • additionCD:

    A tuple that contains the vectors C and D in E = (A + B) * (C + D).

  • result:

    The output vector E in E = (A + B) * (C + D).

Discussion

This function calculates the products of the first N elements of the addition of vectors A and B and the addition of vectors C and D.

 for (n = 0; n < N; ++n)
    E[n] = (A[n]+B[n]) * (C[n]+D[n]);

[Image]

The following code shows an example of using this function:

    let count = 5
    
    let a: [Double] = [ 1,  2,  3,  4,  5]
    let b: [Double] = [10, 20, 30, 40, 50]
    let c: [Double] = [ 5,  4,  3,  2,  1]
    let d: [Double] = [50, 40, 30, 20, 10]
    
    let e = [Double](unsafeUninitializedCapacity: count) {
        buffer, initializedCount in
        
        vDSP.multiply(addition: (a, b),
                      addition: (c, d),
                      result: &buffer)
        
        initializedCount = count
    }
    
    // Prints "[605.0, 968.0, 1089.0, 968.0, 605.0]".
    print(e)

See Also

Multiplication