Function

vDSP_vsmul(_:_:_:_:_:_:)

Multiplies a single-precision scalar value by a single-precision vector.

Declaration

func vDSP_vsmul(_ __A: UnsafePointer<Float>, _ __IA: vDSP_Stride, _ __B: UnsafePointer<Float>, _ __C: UnsafeMutablePointer<Float>, _ __IC: vDSP_Stride, _ __N: vDSP_Length)

Parameters

__A

Single-precision real input vector.

__IA

Stride for A.

__B

Pointer to single-precision real input scalar.

__C

Single-precision real output vector.

__IC

Stride for C.

__N

The number of elements to multiply.

Discussion

This function calculates the products of the first N elements of A and the scalar value B, writing the result to C:

A diagram showing the operation of the vDSP_vsmul function. There are three rows. The top row represents the first input, vector A. The second row represents the second input, scalar 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] = A[n] * B;

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

let stride = vDSP_Stride(1)

let a: [Float] = [1, 2, 4, 5]
var b: Float = 2

let n = vDSP_Length(a.count)

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

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

// Prints "[2.0, 4.0, 8.0, 10.0]"
print(c)

See Also