/*****************************************************************************
*                                                                            *
*   DEMEAN.SPL     Copyright (C) 2002-2015 DSP Development Corporation       *
*                               All Rights Reserved                          *
*                                                                            *
*   Author:       Randy Race                                                 *
*                                                                            *
*   Synopsis:     Remove the mean from a series                              *
*                                                                            *
*   Revisions:    28 Aug 2002  RRR  Creation                                 *
*                 26 Sep 2015  RRR  ITERATE for simple column iteration      *
*                                                                            *
*****************************************************************************/

#if @HELP_DEMEAN

    DEMEAN

    Purpose: Removes the mean (DC value) from a series

    Syntax:  DEMEAN(series)

               series - A series or table.

    Returns: A series or table.

    Example:
             demean(gsin(100, 0.01) + 23)

             returns the sinewave minus the mean, or gsin(100, 0.01).

Remarks:
             DEMEAN removes the mean (or DC value) from a series. 

             DEMEAN is often used when computing the SPECTRUM of a
             series to prevent a large DC value (the first point of a
             spectrum) from visually dominating the plot.

See Also:
             Detrend
             Mean
             Spectrum
#endif


/* remove the mean (DC value) from a series */
ITERATE demean(s, opt)
{
        if (argc < 2)
        {
                if (argc < 1) error("demean - input series required");
                opt = 0;
        }

        return(s - mean(s));
}