vDSP_vaddsub

Declaration

void vDSP_vaddsub(const float *__I0, vDSP_Stride __I0S, const float *__I1, vDSP_Stride __I1S, float *__O0, vDSP_Stride __O0S, float *__O1, vDSP_Stride __O1S, vDSP_Length __N);

Parameters

• __I0:

  The first input vector, A.

• __I0S:

  The distance between the elements in the first input vector.

• __I1:

  The second input vector, B.

• __I1S:

  The distance between the elements in the second input vector.

• __O0:

  The addition output vector, O0.

• __O0S:

  The distance between the elements in the addition output vector.

• __O1:

  The subtraction output vector, O1.

• __O1S:

  The distance between the elements in the subtraction output vector.

• __N:

  The number of elements that the function processes.

Discussion

This function calculates the addition and subtraction of the first N elements of input vectors A and B, and writes the result to output vector C.

 for (i = 0; i < N; ++i)
 {
     i1 = I1[i*I1S];
     i0 = I0[i*I0S];
     O0[i*O0S] = i1 + i0;
     O1[i*O1S] = i1 - i0;
 }

[Image]

The following code shows an example of using this function:

    let stride = 1
    let count = 5
    
    let b: [Float] = [10, 20, 30, 40, 50]
    let a: [Float] = [ 1,  2,  3,  4,  5]
    
    var o0 = [Float](repeating: 0, count: count)
    var o1 = [Float](repeating: 0, count: count)
    
    vDSP_vaddsub(a, stride,
                 b, stride,
                 &o0, stride,
                 &o1, stride,
                 vDSP_Length(count))
    
    // Prints the addition result: "[11.0, 22.0, 33.0, 44.0, 55.0]".
    print(o0)
    
    // Prints the subtraction result: "[9.0, 18.0, 27.0, 36.0, 45.0]".
    print(o1)

See Also

Binary addition and subtraction operations

• vDSP_vaddsubD