#!/usr/pkg/bin/python
"""optimized to plot graph of function that varies with time

   x scale always starts at zero, y varies positive and negative with
   screenheight / 2 as y axis"""
Copyright = """
    dydtplot - show graph of any time-varying function
    Copyright (C) 2004  John Comeau <jc@jcomeau.com>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
    """
errormessage = "Not all needed libraries found, upgrade or check path"
try:
 import sys, os
 import Tkinter
 from types import *
except exception:
 try:
  sys.stderr.write("%s\n" % errormessage)
 except:
  print errormessage
 raise exception

# get name this program was called as, minus .py extension if any
self = sys.argv[0].split(os.sep)[-1].split('.')[0]
# now get name we gave it when we wrote it
originalself = Copyright.split()[0]

# routines that should be in every program
# (yes, you could import them, but that causes problems too, don't go there)

def dbgprint(*whatever):
 sys.stderr.write("%s\n" % repr(whatever))

def setvalue(name, default, **options):
 if options.has_key(name):
  return options[name]
 options[name] = default
 return options[name]

globals = {} # this can make it easier, put everything in a dictionary

# other globals, specific to this program
xmax = 128 # these can always be resized by user later
ymax = 128
# globals derived from those above, or defined later in program
tk = Tkinter.Tk(self)
canvas = Tkinter.Canvas(tk, {'height': ymax, 'width': xmax})
wave = None

def dydtplot(*args, **options):
 global self, xmax, ymax, tk, canvas, wave
 canvas.pack({'expand': True, 'fill': 'both'})
 tk.bind('<Configure>', redraw)
 if type(args[0]) is ListType:
  wave = args[0]
 elif type(args[0]) is TupleType:
  wave = args[0].tolist()
 else:
  wave = args
 wave = map(float, wave) # in case of command-line testing (strings)
 dbgprint('wave', wave)
 draw()
 tk.mainloop()

def redraw(this):
 """set xmax and ymax after resize, then draw the graph anew

    do it this way, two functions, because otherwise draw() will think
    height and width are 1 pixel for some reason"""
 global canvas, xmax, ymax
 xmax, ymax = canvas.winfo_width(), canvas.winfo_height()
 draw()

def draw():
 """display the global array 'wave' as a graph

    scaling assumes that y varies between -1 and 1"""
 global canvas, wave, xmax, ymax
 if len(wave) < 1: return
 yscale = ymax / 2.0
 ymidpoint = int(yscale)
 dbgprint(xmax, yscale, ymidpoint, wave)
 for i in range(0, xmax - 4):
  # tk canvas seems to be padded such that if you draw anything with x
  # coordinates of 0 or 1 it will not be seen...
  # since I don't know how to get this info programmatically I will
  # just kludge it by adding 2 to the x value
  try:
   canvas.create_line((i + 2, ymidpoint,
    i + 2, ymidpoint - (yscale * wave[i])))
  except:
   pass

if __name__ == '__main__':
 # if this program was imported by another, the above test will fail,
 # and this following code won't be used...
 # however, if this program was invoked directly, by whatever name,
 # the name used will be treated as a function call.
 # the simplest case would be that it was invoked as its original name,
 # in which case it will just call the main routine
 try:
  eval("%s(sys.argv[1:])" % self)
 except:
  sys.stderr.write("""Usage: %s [OPTIONS] INFILE[...]
  or for more detailed help, read source or:
  pydoc %s """ % (originalself, originalself))
  raise