ansjsun

import numpy as	np
from scipy.optimize import fmin_bfgs

def rosen(x):
   return sum(100.0*(x[1:]-x[:-1]**2.0)**2.0 + (1-x[:1])**2.0)

def rosen_der(x):
   xm = x[1:-1]
   xm_m1 = x[:-2]
   xm_p1 = x[2:]

ansjsun

#!/usr/bin/python

# crf.py (by Graham Neubig)
#  This script trains conditional random fields (CRFs)
#  stdin: A corpus of WORD_POS WORD_POS WORD_POS sentences
#  stdout: Feature vectors for emission and transition properties

from collections import defaultdict
from math import log, exp
import sys