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vDSP_vasmD

Calculates the double-precision element-wise product of the sum of two vectors and a scalar value, using the specified stride.

Declaration

extern void vDSP_vasmD(const double *__A, vDSP_Stride __IA, const double *__B, vDSP_Stride __IB, const double *__C, double *__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 input vector D.

  • __N:

    The number of elements that the function processes.

Discussion

This function calculates the element-wise sum of vectors A and B, multiplies the sum by scalar value C, 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: [Double] = [ 1,  2,  3,  4,  5]
    let b: [Double] = [10, 20, 30, 40, 50]
    let c: Double = 5
    
    let d = [Double](unsafeUninitializedCapacity: count) {
        buffer, initializedCount in
        
        vDSP_vasmD(a, stride,
                   b, stride,
                   [c],
                   buffer.baseAddress!, stride,
                   vDSP_Length(count))
        
        initializedCount = count
    }
    
    // Prints "[55.0, 110.0, 165.0, 220.0, 275.0]".
    print(d)

See Also

Vector-vector-scalar add-multiply operations