vDSP_vsmsma

Declaration

extern void vDSP_vsmsma(const float *__A, vDSP_Stride __IA, const float *__B, const float *__C, vDSP_Stride __IC, const float *__D, float *__E, vDSP_Stride __IE, vDSP_Length __N);

Parameters

• __A:

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

• __IA:

  The distance between the elements in the input vector A.

• __B:

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

• __C:

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

• __IC:

  The distance between the elements in the input vector C.

• __D:

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

• __E:

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

• __IE:

  The distance between the elements in the output vector E.

• __N:

  The number of elements that the function processes.

Discussion

This function calculates the element-wise vector-scalar products of A and B, and C and D, and writes the sum of the products to vector D.

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

[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
    let c: [Float] = [ 5,  4,  3,  2,  1]
    let d: Float = 50
    
    let e = [Float](unsafeUninitializedCapacity: count) {
        buffer, initializedCount in
        
        vDSP_vsmsma(a, stride,
                    [b],
                    c, stride,
                    [d],
                    buffer.baseAddress!, stride,
                    vDSP_Length(count))
        
        initializedCount = count
    }
    
    // Prints "[260.0, 220.0, 180.0, 140.0, 100.0]".
    print(e)

See Also

Vector-scalar-vector-scalar multiply-multiply-add operations

• vDSP_vsmsmaD