#!/usr/bin/python -Wall

# ================================================================
# John Kerl
# kerl.john.r@gmail.com
# 2005-07-05
# Ported from Perl to Python
# 2008-02-06
# ================================================================
# This software is released under the terms of the GNU GPL.
# Please see LICENSE.txt in the same directory as this file.
# ================================================================

from __future__ import division # 1/2 = 0.5, not 0.
import sys
from sackmat_m import *

# ----------------------------------------------------------------
def usage():
	print >> sys.stderr, "Usage: %s [options] {file name}" % (sys.argv[0])
	print >> sys.stderr, "Options:"
	print >> sys.stderr, "-spec:  print spectrum only."
	print >> sys.stderr, "Use \"-\" as file name if input is stdin."
	print >> sys.stderr, "Note:  input must be real symmetric."
	sys.exit(1)

# ----------------------------------------------------------------
spectrum_only = 0;

argc = len(sys.argv)
if (argc < 2):
	usage()

argi = 1
while (argi < argc):
	if (sys.argv[argi] ==  '-h'):
		usage()
	elif (sys.argv[argi] ==  '--help'):
		usage()
	elif (sys.argv[argi] == '-spec'):
		spectrum_only = 1
	elif (sys.argv[argi] == '-'):
		break
	elif (sys.argv[argi][0] == '-'):
		print >> sys.stderr, "Unrecognized option \"%s\"." % (sys.argv[argi])
		usage()
	else:
		break
	argi += 1

if ((argc - argi) != 1):
	print >> sys.stderr, "%s: Need exactly one file name." % (sys.argv[0])
	usage()
file_name = sys.argv[argi]

# ----------------------------------------------------------------
A = read_matrix(float, file_name)
nr = A.square_dim()

[L, V] = rs_eigensystem(A)

if (spectrum_only):
	L.sort()
	print_column_vector(L)
else:
	print_column_vector(L)
	print
	V.printf()  # eigenvectors