Contents

multiply(subtraction:subtraction:)

Returns the double-precision element-wise product of the differences of two pairs of vectors.

Declaration

static func multiply<R, S, T, U>(subtraction subtractionAB: (a: R, b: S), subtraction subtractionCD: (c: T, d: U)) -> [Double] where R : AccelerateBuffer, S : AccelerateBuffer, T : AccelerateBuffer, U : AccelerateBuffer, R.Element == Double, S.Element == Double, T.Element == Double, U.Element == Double

Parameters

  • subtractionAB:

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

  • subtractionCD:

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

Return Value

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

Discussion

This function calculates the products of the first N elements of the subtraction of vectors A and B and the subtraction 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 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 = vDSP.multiply(subtraction: (a, b),
                          subtraction: (c, d))
    
    // Prints "[405.0, 648.0, 729.0, 648.0, 405.0]".
    print(e)

See Also

Multiplication