Multiplies the sum of two single-precision vectors by a single-precision scalar value.


func vDSP_vasm(_ __A: UnsafePointer<Float>, _ __IA: vDSP_Stride, _ __B: UnsafePointer<Float>, _ __IB: vDSP_Stride, _ __C: UnsafePointer<Float>, _ __D: UnsafeMutablePointer<Float>, _ __ID: vDSP_Stride, _ __N: vDSP_Length)



Single-precision real input vector.


Stride for A.


Single-precision real input vector.


Stride for B.


Single-precision real input scalar.


Single-precision real output vector.


Stride for D.


The number of elements to process.


This function calculates the sums of the first N elements of A and B, multiplies each sum by the scalar value C, and writes the result to D:

A diagram showing the operation of the vDSP_vasm function. There are five rows. The top two rows represents the first two inputs, vector A and vector B. The third row represents the intermediate result of the first two inputs. The forth row represents the third input, scalar C. The bottom row represents the output, vector D. The diagram has connecting lines from the inputs to the output vector indicating the relationships between the inputs and output.

The operation is:

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

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

let stride = vDSP_Stride(1)

let a: [Float] = [10, 20, 30, 40, 50]
let b: [Float] = [ 1,  2,  3,  4,  5]

var c: Float = 2

let n = vDSP_Length(a.count)

var d = [Float](repeating: 0,
                count: a.count)

vDSP_vasm(a, stride,
          b, stride,
          &d, stride,

// Prints "[22.0, 44.0, 66.0, 88.0, 110.0]"

See Also

Ternary (Vector-Vector-Scalar) Add-Multiply Operations