/*****************************************************************************
*                                                                            *
*   GBLCKMAN.SPL  Copyright (C) 2004 DSP Development Corporation             *
*                               All Rights Reserved                          *
*                                                                            *
*   Author:      Randy Race                                                  *
*                                                                            *
*   Synopsis:    Generates a Blackman window                                 *
*                                                                            *
*   Revisions:   19 Mar 2004  RRR  Creation                                  *
*                                                                            *
*****************************************************************************/


#if @HELP_GBLCKMAN

    GBLCKMAN

    Purpose: Generates a Blackman Window.

    Syntax:  GBLCKMAN(points, spacing)

               points  - Number of points to generate.

               spacing - Spacing between points.


    Returns: A series.

    Example:

             gblckman(100, .01)

             Creates a 100-point Blackman window with points spaced with an
             interval of 0.01 using the following formula:

             w[k] = 0.42 - 0.50 * cos(2*pi*(k-1)/(N-1))
                         + 0.08 * cos(4*pi*(k-1)/(N-1))

             where k is the kth point (1 <= k <= N) and N is 100, the number
             of points to generate. The spacing between samples is set
             to 0.01.

    Remarks:

             Use the Blackman function to automatically create and multiply
             a Blackman Window with a series. For example:

             blackman(W2)

             multiplies Window 2 with a Blackman Window calculated to the same
             length and spacing as the series in W2.

             Blackman, Flattop, Hamming, Hanning, and Kaiser Windows are
             useful in creating FIR filters and in preprocessing series
             for FFT calculations.

    See Also:
             Blackman
             Fft
             Gflattop
             Ghamming
             Ghanning
             Gkaiser
             Psd
             Spectrum
#endif



/* generate an N point Blackman window */
gblckman(n, dx, sym)
{
        return(gblackman(n, dx, sym));
}