Function

vDSP_zvcmul(_:_:_:_:_:_:_:)

Multiplies a single-precision complex vector by the conjugate of another single-precision complex vector.

Declaration

func vDSP_zvcmul(_ __A: UnsafePointer<DSPSplitComplex>, _ __IA: vDSP_Stride, _ __B: UnsafePointer<DSPSplitComplex>, _ __IB: vDSP_Stride, _ __C: UnsafePointer<DSPSplitComplex>, _ __IC: vDSP_Stride, _ __N: vDSP_Length)

Parameters

__A

Single-precision complex input vector.

__IA

Stride for A.

__B

Single-precision complex input vector.

__IB

Stride for B.

__C

Single-precision complex output vector.

__IC

Stride for C.

__N

The number of elements to process.

Discussion

This function calculates the products of the first N complex conjugates of A by the corresponding complex elements of B, writing the result to C:

A diagram showing the operation of the vDSP_zvcmul function. There are three rows. The top row represents the first input, vector A. The second row represents the second input, vector B. The bottom row represents the output, vector C. The diagram has connecting lines from the input vectors to the output vector indicating the relationships between the inputs and output.

The operation is:

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

The following code shows an example of using vDSP_zvcmul(_:_:_:_:_:_:_:):

let n = vDSP_Length(4)
let stride = vDSP_Stride(1)

var realA: [Float] = [2, 3, 4, 5]
var realB: [Float] = [1, 2, 3, 4]

var imagA: [Float] = [10, 20, 30, 40]
var imagB: [Float] = [4, 3, 2, 1]

var a = [DSPSplitComplex(realp: &realA,
                         imagp: &imagA)]

var b = [DSPSplitComplex(realp: &realB,
                         imagp: &imagB)]

var realC = [Float](repeating: .nan, count: Int(n))
var imagC = [Float](repeating: .nan, count: Int(n))
var c = DSPSplitComplex(realp: &realC,
                        imagp: &imagC)

vDSP_zvcmul(&a, stride,
           &b, stride,
           &c, stride,
           n)

print("real", realC) // Prints "real [42.0, 66.0, 72.0, 60.0]"
print("imag", imagC) // Prints "imag [-2.0, -31.0, -82.0, -155.0]"

See Also

Binary Conjugate-Multiply Operations

Beta Software

This documentation contains preliminary information about an API or technology in development. This information is subject to change, and software implemented according to this documentation should be tested with final operating system software.

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