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vDSP_blkman_window

Creates a single-precision Blackman window.

Declaration

extern void vDSP_blkman_window(float *__C, vDSP_Length __N, int __Flag);

Parameters

  • __C:

    The output vector.

  • __N:

    The number of elements in the output vector.

  • __Flag:

    A value that specifies whether the function creates a half window or a full window. Pass the Vdsp_half_window flag to create only the first (N+1)/2 points; pass 0 to create a full-size window.

Discussion

The vDSP_blkman_window and vDSP_blkman_windowD functions create a Blackman window vector using the following operation:

for (n=0; n < N; ++n)
{
    C[n] = 0.42 - (0.5 * cos(  2 * pi * n / N ) ) +
             (0.08 * cos( 4 * pi * n / N) );
}

The following code shows how to generate a Blackman window.

let n = vDSP_Length(1024)

var c = [Float](repeating: 0,
                count: Int(n))

vDSP_blkman_window(&c,
                   n,
                   0)

The following illustrates the values of the output vector, c:

[Image]

See Also

Vector generation with window functions