Initial commit of OpenSPARC T2 architecture model.

[OpenSPARC-T2-SAM] / sam-t2 / devtools / v9 / lib / python2.4 / lib-old / poly.py

# module 'poly' -- Polynomials

# A polynomial is represented by a list of coefficients, e.g.,
# [1, 10, 5] represents 1*x**0 + 10*x**1 + 5*x**2 (or 1 + 10x + 5x**2).
# There is no way to suppress internal zeros; trailing zeros are
# taken out by normalize().

def normalize(p): # Strip unnecessary zero coefficients
   n = len(p)
   while n:
       if p[n-1]: return p[:n]
       n = n-1
   return []

def plus(a, b):
   if len(a) < len(b): a, b = b, a # make sure a is the longest
   res = a[:] # make a copy
   for i in range(len(b)):
       res[i] = res[i] + b[i]
   return normalize(res)

def minus(a, b):
   neg_b = map(lambda x: -x, b[:])
   return plus(a, neg_b)

def one(power, coeff): # Representation of coeff * x**power
   res = []
   for i in range(power): res.append(0)
   return res + [coeff]

def times(a, b):
   res = []
   for i in range(len(a)):
       for j in range(len(b)):
           res = plus(res, one(i+j, a[i]*b[j]))
   return res

def power(a, n): # Raise polynomial a to the positive integral power n
   if n == 0: return [1]
   if n == 1: return a
   if n/2*2 == n:
       b = power(a, n/2)
       return times(b, b)
   return times(power(a, n-1), a)

def der(a): # First derivative
   res = a[1:]
   for i in range(len(res)):
       res[i] = res[i] * (i+1)
   return res

# Computing a primitive function would require rational arithmetic...