def _get_integer_intervals(xmin, xmax):
    """
    For a given interval [xmin, xmax], returns the minimum interval [iXmin, iXmax] that contains the original one where iXmin and iXmax are Integer numbers.

    Examples:  [ 3.45,  5.35]  =>  [ 3,  6]
               [-3.45,  5.35]  =>  [-4,  6]
               [-3.45, -2.35]  =>  [-4, -2]

    Parameters
    ----------

    xmin: float
        origin of the interval

    xmax: float
        end of the interval

    Returns
    -------
    Returns the interval [iXmin, iXmax]

    iXmin: integer
        Minimum value of the integer interval

    iMmax: integer
        Maximum value of the integer interval

    """

    if(xmin<0.0 and xmin!=int(xmin)):
        iXmin=int(xmin-1)
    else:
        iXmin = int(xmin)

    if(xmax==int(xmax)):
        iXmax=xmax
    else:
        iXmax=int(xmax+1)

    return iXmin, iXmax