vDSP_vmsa

Declaration

extern void vDSP_vmsa(const float *__A, vDSP_Stride __IA, const float *__B, vDSP_Stride __IB, const float *__C, float *__D, vDSP_Stride __ID, vDSP_Length __N);

Parameters

• __A:

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

• __IA:

  The distance between the elements in the input vector A.

• __B:

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

• __IB:

  The distance between the elements in the input vector B.

• __C:

  The input scalar value C in D = (A * B) + C.

• __D:

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

• __ID:

  The distance between the elements in the output vector D.

• __N:

  The number of elements that the function processes.

Discussion

This function calculates the element-wise product of vectors A and B, adds scalar value C to the product, and writes the result to vector D.

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

[Image]

The following code shows an example of using this function:

    let stride = 1
    let count = 5
    
    let a: [Float] = [ 1,  2,  3,  4,  5]
    let b: [Float] = [10, 20, 30, 40, 50]
    let c: Float = 5
    
    let d = [Float](unsafeUninitializedCapacity: count) {
        buffer, initializedCount in
        
        vDSP_vmsa(a, stride,
                  b, stride,
                  [c],
                  buffer.baseAddress!, stride,
                  vDSP_Length(count))
        
        initializedCount = count
    }
    
    // Prints "[15.0, 45.0, 95.0, 165.0, 255.0]s".
    print(d)

See Also

Vector-vector-scalar multiply-add operations

• vDSP_vmsaD