;+
; NAME:
;  c2r
; PURPOSE: (one line)
;  Complex to real
; DESCRIPTION:
;  Complex to real (pull out the real, imaginary, amplitude, phase
;  from a complex number)
; CATEGORY:
;  math
; CALLING SEQUENCE:
;  our = c2r(c)
; INPUTS:
;  c - complex numbe or array, a + i b = c * exp(i * p)
; KEYWORDS
;  real: (a, in a + i b)
;  imaginary: (b, in a + i b)
;  amplitude: (c, in c * exp(i * p)
;  phase: (p, in c * exp(i * p)
;  oreal: if set, output real
;  oimaginary: if set, output imaginary
;  oamplitude: if set, output amplitude
;  ophase: if set, output phase
; OUTPUTS:
;  real (default), imaginary, amplitude, or phase
; OPTIONAL OUTPUTS:
; MODIFICATION HISTORY:
;  Written 2012 Sep 29, by Leslie Young, SwRI
;  2016 Mar 22 LAY. Modified for inclusion in math library.
;-

; c2r - complex to reals (should change this name!)
; INPUT
;  c - array of complex
; OUTPUT
;  real, imaginary, amplitude, or phase
;  phase P s.t. c = |c| exp(i * p)

function c2r, c, real=real, imaginary=imaginary, amplitude=amplitude, phase=phase, $,
                  oreal=oreal, oimaginary=oimagninary, oamplitude=oamplitude, ophase=ophase

    real = float(c)
    imaginary = imaginary(c)
    amplitude = abs(c)
    phase = atan(imaginary, real)
    if keyword_set(oimaginary) then return, imaginary
    if keyword_set(oamplitude) then return, amplitude
    if keyword_set(ophase) then return, phase
    return, real

 end