/*****************************************************************************
*                                                                            *
*   ISINF.SPL   Copyright (C) 2002-2014 DSP Development Corporation          *
*                               All Rights Reserved                          *
*                                                                            *
*   Author:      Randy Race                                                  *
*                                                                            *
*   Synopsis:    Returns 1 for each element that is inf                      *
*                                                                            *
*   Revisions:    9 Aug 2002  RRR  Creation                                  *
*                 5 Feb 2011  RRR  Complex support                           *
*                26 Jun 2014  RRR  use internal isinfvalue function          *
*                                                                            *
*****************************************************************************/


#if @HELP_ISINF

    ISINF

    Purpose: Returns 1 for each element that is infinite (inf)

    Syntax:  ISINF(ser)

              ser - Series

    Returns: A series where each element is 1 where the input series has
             an INF value and 0 where the input series is not INF.

    Example:
             a = {1, 2, inf, 3};
             b = 5;
             c = {};

             isinf(a) returns {0, 0, 1, 0}
             isinf(b) returns {0}
             isinf(c) returns {}

    Remarks:
             ISINF always returns a series.

             ISINF returns an empty series if the input is an empty series.

    See Also:
             Finite
             Isempty
             Isnan
#endif


/* where is input inf? */
isinf(a)
{
        if (argc < 1) error("isinf - input required");

        /* check empty window */
        if (iswinempty(a))
        {
                a = {};
        }
        else if (not(isarray(a)))
        {
                /* convert to series if not already */
                a = castseries(a);
        }

        return(isinfvalue(a));
}