def is_divisible(self, f):
left, out = f, []
factors = list(self.factors)
change = True
while change:
change = False
for i in range(len(factors)):
d = factor.try_divide(factors[i], left)
if d == None: continue
if type(d) != polynomial.constant and not \
(type(d) == polynomial.polynomial and \
(d.equals(polynomial.polynomial_parser('1')) or \
d.equals(polynomial.polynomial_parser('0')))):
changed = True
if factor.is_polynomial(factors[i]) or factor.is_factorial(
factors[i]):
factors[i] = factors[i].divide(d)[0]
else:
factors[i] = factors[i].divide(d)
if factor.is_polynomial(left) or factor.is_factorial(left):
left = left.divide(d)[0]
else:
left = left.divide(d)
out.append(d)
return out
def binom(n, k):
if type(n) == str: n = polynomial.polynomial_parser(n)
if type(k) == str: k = polynomial.polynomial_parser(k)
num = expression_add([expression_mult([factor.factorial(n)])])
den = expression_add([
expression_mult([
factor.factorial(k),
factor.factorial(
polynomial.polynomial_parser('{}-({})'.format(
n.to_string(), k.to_string())))
])
])
return expression_rat(num, den)
def get_A(q, r, L, l, variables, variable='k'):
qd, _ = polynomial2dict(
polynomial.polynomial_parser(q.to_string().replace(
variable, '({}+1)'.format(variable))), variables)
rd, _ = polynomial2dict(r, variables)
kvar_index = variables.index(variable)
V = len(variables)
A = [[0] * (l**V) for _ in range(L**V)]
#Adding to A due to factor q_{k+1}f_k.
for row in range(L**V):
i = [(row // L**s) % L for s in range(V)]
for col in range(l**V):
j = [(col // l**s) % l for s in range(V)]
jq = [i[s] - j[s] for s in range(V)]
A[row][col] += qd[tuple(jq)]
#Filling in A due to factor r_k f_{k-1}.
for row in range(L**V):
i = [(row // L**s) % L for s in range(V)]
for col in range(l**V):
j = [(col // l**s) % l for s in range(V)]
jr = [i[s] - j[s] for s in range(V)]
a = j[kvar_index]
for s in range(a, l):
A[row][col + (s - a) * l**kvar_index] -= rd[tuple(jr)] * pow(
-1, s - a) * n_choose_k(s, a)
return A
def get_pqr(num, den, variable):
q, r = num, den
p = polynomial.polynomial([polynomial.constant(1)], 'n')
zero = get_common_factor(q, r, variable)
while zero != None:
g = q.gcd(
polynomial.polynomial_parser(r.to_string().replace(
variable, '({}+{})'.format(variable, zero))))
q = q.divide(g)[0]
r = r.divide(
polynomial.polynomial_parser(g.to_string().replace(
variable, '({}-{})'.format(variable, zero))))[0]
for i in range(zero):
p = p.multiply(
polynomial.polynomial_parser(g.to_string().replace(
variable, '({}-{})'.format(variable, i))))
zero = get_common_factor(q, r, variable)
return p, q, r
def __init__(self, base, exponent):
self.base = base
self.exponent = polynomial.polynomial_parser(exponent.to_string())
assert type(self.base) == int, 'Base has to be int, not {}'.format(
type(self.base))
assert is_polynomial(
self.exponent
), 'Exponent has to be polynomial.polynomial, not {}'.format(
type(self.exponent))
def try_algo(num, den, variable='k', test_number=None):
if num == '' or den == '': return
num, den = polynomial.polynomial_parser(num), polynomial.polynomial_parser(
den)
vars = num.get_common_variables(den)
num, den = num.convert_polynomial(vars), den.convert_polynomial(vars)
print('=============TRY ALGO STARTED{}==============='.format(
test_number if test_number != None else ''))
print('Numerator: {}\nDenominator: {}\n'.format(num.to_string(),
den.to_string()))
p, q, r = gosper.get_pqr(num, den, variable)
q, r, p = polynomial.polynomial_parser(
q.to_string()), polynomial.polynomial_parser(
r.to_string()), polynomial.polynomial_parser(p.to_string())
print('p: {}\nq: {}\nr: {}\n'.format(p.to_string(), q.to_string(),
r.to_string()))
f = get_f(p, q, r)
print('f: {}\n'.format(f if f == None else f.to_string()))
print('==============TRY ALGO ENDED================')
def multiply(self, other):
if self.base == other.base:
exp = self.exponent.add(other.exponent)
if is_positive_constant(exp):
return polynomial.constant(
pow(
self.base,
polynomial.polynomial_parser(
exp.to_string()).coefficients[0]))
return power(self.base, exp)
elif self.exponent.equals(other.exponent):
return power(self.base * other.base, self.exponent)
return None
def dict2polynomial(d, v):
out = []
for x in d:
if d[x] == 0: continue
out2 = ['(', d[x]]
for i in range(len(v)):
out2.append('{}{}{}'.format(v[i] if x[i] > 0 else '',
'^' if x[i] > 1 else '',
x[i] if x[i] > 1 else ''))
out2.append(')')
out.append(''.join(map(str, out2)))
s = '+'.join(out)
return polynomial.polynomial_parser(s)
def to_polynomial(x, l, variables):
out = []
V = len(variables)
for i in range(l**V):
if x[i] == 0: continue
out2 = ['(', x[i]]
for j in range(V):
a = (i // (l**j)) % l
out2.append('{}{}{}'.format(variables[j] if a > 0 else '',
'^' if a > 1 else '',
a if a > 1 else ''))
out2.append(')')
out.append(''.join(map(str, out2)))
return polynomial.polynomial_parser('+'.join(out))
def test_get_pqr(num, den, variable='k'):
if num == '' or den == '':
print('==============================')
print(
'Testing Gosper does not work for numerator and denominator\n{}\n{}'
.format(num, den))
print('==============================')
return
print('======TESTING GOSPER======')
p1, p2 = polynomial.polynomial_parser(num), polynomial.polynomial_parser(
den)
print(num)
print(den)
print('Numerator: {}'.format(p1.to_string()))
print('Denominator: {}'.format(p2.to_string()))
p, q, r = get_pqr(p1, p2, variable)
print('Now we have:')
print('q =', q.to_string())
print('r =', r.to_string())
print('p =', p.to_string())
print('such that p(n)*q(n)/(p(n-1)*r(n))')
print_break()
print()
def WZmethod(parser, s, variable='k', max_degree=5):
F, (ak_poly, ak_rest), num, den = parser(s)
assert factor.is_polynomial(num) and factor.is_polynomial(
den), 'Wrong type num, den'
p, q, r, f = gosper.gosper(num,
den,
variable=variable,
max_degree=max_degree)
# p.PRINT()
# q.PRINT()
# r.PRINT()
if f == None: return None
ak_poly_num, ak_poly_den = ak_poly.num.addends[0].factors[
0], ak_poly.den.addends[0].factors[0]
Snum = ak_poly_num.multiply(
f.multiply(
polynomial.polynomial_parser(q.to_string().replace(
variable, '({}+1)'.format(variable)))))
Sden = ak_poly_den.multiply(p)
g = Snum.gcd(Sden)
Snum = Snum.divide(g)[0]
Sden = Sden.divide(g)[0]
Snum1 = polynomial.polynomial_parser(Snum.to_string().replace(
variable, '({}-1)'.format(variable)))
Sden1 = polynomial.polynomial_parser(Sden.to_string().replace(
variable, '({}-1)'.format(variable)))
S = '(({})/({}))({})'.format(Snum.to_string(), Sden.to_string(), ak_rest)
R = '({})/({})'.format(Snum1.to_string(), Sden1.to_string())
G = '(({})/({}))({})'.format(
Snum1.to_string(), Sden1.to_string(),
ak_rest.replace(variable, '({}-1)'.format(variable)))
# print(s)
# print()
# print(F)
# print()
# print(G)
return F, G, R
def get_f(p, q, r, max_degree=5, variable='k'):
variables = p.get_common_variables(q.multiply(r))
p, q, r = polynomial.polynomial_parser(
p.to_string(), variables), polynomial.polynomial_parser(
q.to_string(),
variables), polynomial.polynomial_parser(r.to_string(), variables)
l = max_degree + 1
L = l + max(get_degree(q), get_degree(r))
assert L >= get_degree(
p) + 1, 'Does not work to get f because to low degree: {}'.format(
max_degree)
B = get_B(p, L, variables)
A = get_A(q, r, L, l, variables)
x = gaussianelimination.gauss(A, B)
if x == None: return None
ret = to_polynomial(x, l, variables)
qf = polynomial.polynomial_parser(q.to_string().replace(
variable, '({}+1)'.format(variable))).multiply(ret)
rf = polynomial.polynomial_parser(ret.to_string().replace(
variable, '({}-1)'.format(variable))).multiply(r)
assert p.equals(qf.add(rf.negate(
))), 'Error for p={}, q={}, r={}. Got f={} which is wrong.'.format(
p.to_string(), q.to_string(), r.to_string(), f.to_string())
return ret
def divide(self, other):
if factor.is_power(other):
return self.multiply(expression_mult([other.inverse()]))
left = other
factors = list(self.factors)
while not (factor.is_polynomial(left)
and left.equals(polynomial.constant(1))):
for i in range(len(factors)):
d = factor.try_divide(factors[i], left)
if d == None: continue
if factor.is_polynomial(d) and d.equals(
polynomial.polynomial_parser('1')):
continue
if type(factors[i]) in [
polynomial.polynomial, factor.factorial
]:
factors[i] = factors[i].divide(d)[0]
else:
factors[i] = factors[i].divide(d)
if type(left) in [polynomial.polynomial, factor.factorial]:
left = left.divide(d)[0]
else:
left = left.divide(d)
return expression_mult(factors)
def get_common_factor(q, r, variable):
rj = polynomial.polynomial_parser(r.to_string().replace(
variable, '({}+j)'.format(variable)))
#Want to find j such that gcd between q and rj is not 1.
return find_zeros(q, rj)
def parse_rel_part(s):
s = s.replace('\\cdot', '*')
def get_next_part_end(s, i):
if s[i + 1] == '{':
j = i + 1
parcount = 1
while parcount:
j += 1
if s[j] == '{': parcount += 1
elif s[j] == '}': parcount -= 1
return j
if s[i + 1].isdigit():
j = i + 1
while j < len(s) - 1 and s[j + 1].isdigit():
j += 1
return j
return i + 1
def get_prev_part_start(s, i):
if s[i - 1] == ']':
j = i - 1
while s[j] != '[':
j -= 1
return j - 1
if s[i - 1] == ')':
j = i - 1
parcount = -1
while parcount:
j -= 1
if s[j] == '(': parcount += 1
elif s[j] == ')': parcount -= 1
return j
if s[i - 1].isdigit():
j = i - 1
while j > 0 and s[j - 1].isdigit():
j -= 1
return j
return i - 1
# print(s)
i = s.find('\\binom')
while i != -1:
i0 = s.find('{', i)
i1, parcount = i0, 1
while parcount:
i1 += 1
if s[i1] in '{}': parcount += 1 if s[i1] == '{' else -1
i2 = s.find('{', i1)
i3, parcount = i2, 1
while parcount:
i3 += 1
if s[i3] in '{}': parcount += 1 if s[i3] == '{' else -1
s = s[:i] + 'B[{},{}]'.format(parse_rel_part(
s[i0 + 1:i1]), parse_rel_part(s[i2 + 1:i3])) + s[i3 + 1:]
i = s.find('\\binom')
i = s.find('\\frac')
# print(s)
while i != -1:
i0 = s.find('{', i)
i1, parcount = i0, 1
while parcount:
i1 += 1
if s[i1] in '{}': parcount += 1 if s[i1] == '{' else -1
i2 = s.find('{', i1)
i3, parcount = i2, 1
while parcount:
i3 += 1
if s[i3] in '{}': parcount += 1 if s[i3] == '{' else -1
s = s[:i] + '({})/({})'.format(parse_rel_part(
s[i0 + 1:i1]), parse_rel_part(s[i2 + 1:i3])) + s[i3 + 1:]
i = s.find('\\frac')
i = s.find('!')
# print(s)
while i != -1:
j = get_prev_part_start(s, i)
s = s[:j] + 'F[{}]'.format(s[j:i]) + s[i + 1:]
i = s.find('!')
# print(s)
i = s.find('^')
while i != -1:
j2 = get_next_part_end(s, i)
if all(ch.isdigit() for ch in s[i + 1:j2 + 1]):
j1 = get_prev_part_start(s, i)
s = s[:j1] + s[j1:i] * int(s[i + 1:j2 + 1]) + s[j2 + 1:]
else:
j1 = get_prev_part_start(s, i)
if j2 == i + 1:
s = s[:j1] + 'P[{},{}]'.format(
polynomial.polynomial_parser(s[j1:i]).to_string(),
s[i + 1:j2 + 1]) + s[j2 + 1:]
else:
s = s[:j1] + 'P[{},{}]'.format(
polynomial.polynomial_parser(s[j1:i]).to_string(),
s[i + 2:j2]) + s[j2 + 1:]
i = s.find('^')
# print(s)
return s
def is_positive_constant(p):
c = polynomial.polynomial_parser(p.to_string())
return type(c) == polynomial.constant and c.coefficients[0] >= 0
def expression_parser(s):
def simplify(stack):
if len(stack) == 1: return stack
if stack[-2] == '(': return stack
if stack[-1] == '(':
stack.append(to_expr_r(polynomial.constant(0)))
return stack
b, op, a = stack.pop(), stack.pop(), stack.pop()
if a == '(':
stack.append(a)
assert op == '-', 'Something is weird'
stack.append(b.negate())
return simplify(stack)
if op == '+':
stack.append(a.add(b))
elif op == '-':
stack.append(a.subtract(b))
elif op == '*':
stack.append(a.multiply(b))
elif op == '/':
stack.append(a.divide(b))
else:
print('SOMETHING IS GOING WRONG')
print('TRYING TO SIMPLIFY AND HAVE a, op, b AS')
try:
print(type(a))
a.PRINT()
except:
print(a)
try:
print(type(op))
op.PRINT()
except:
print(op)
try:
print(type(b))
b.PRINT()
except:
print(b)
raise Exception('Parse general error')
return simplify(stack)
to_split = ['B[', 'F[', 'P[', ']', ',', '/', '*', '+', '-', '(', ')', '^']
s = s.replace(' ', '')
for x in to_split:
s = s.replace(x, ' {} '.format(x))
parts = s.split()
stack = []
i = 0
while i < len(parts):
part = parts[i]
if len(part) == 0:
i += 1
continue
assert part != ',' and part != ']', 'Parse general error for string {}'.format(
s)
if part == '(':
if stack and type(stack[-1]) == expression_rat:
stack.append('*')
stack.append('(')
i += 1
elif part == ')':
stack = simplify(stack)
stack = stack[:-2] + stack[-1:]
i += 1
elif part == 'B[':
if stack and type(stack[-1]) == expression_rat:
stack.append('*')
j = i + 1
while parts[j] != ',':
j += 1
n = polynomial.polynomial_parser(''.join(parts[i + 1:j]))
i = j
j = i + 1
while parts[j] != ']':
j += 1
k = polynomial.polynomial_parser(''.join(parts[i + 1:j]))
stack.append(to_expr_r(binom(n, k)))
i = j + 1
elif part == 'F[':
if stack and type(stack[-1]) == expression_rat:
stack.append('*')
j = i + 1
while parts[j] != ']':
j += 1
stack.append(
to_expr_r(
factor.factorial(
polynomial.polynomial_parser(''.join(parts[i +
1:j])))))
i = j + 1
elif part == 'P[':
if stack and type(stack[-1]) == expression_rat:
stack.append('*')
j = i + 1
while parts[j] != ',':
j += 1
a = int(''.join(parts[i + 1:j]))
i = j
j = i + 1
while parts[j] != ']':
j += 1
n = polynomial.polynomial_parser(''.join(parts[i + 1:j]))
stack.append(to_expr_r(factor.power(a, n)))
i = j + 1
elif part in ['/', '*']:
stack.append(part)
i += 1
elif part in ['+', '-']:
stack = simplify(stack)
stack.append(part)
i += 1
elif part == '^':
cur = stack.pop()
stack.append(cur.power(int(parts[i + 1])))
i += 2
else:
if stack and type(stack[-1]) == expression_rat:
stack.append('*')
stack.append(to_expr_r(polynomial.polynomial_parser(part)))
i += 1
stack = simplify(stack)
return stack[0]
'''Used for testing. Gets F(n,k) and returns a_k/a_{k-1}'''
def get_quotient(fnk):
num_string = '({})-({})'.format(fnk.replace('n', '(n+1)'), fnk)
den_string = num_string.replace('k', '(k-1)')
quot_string = '({})/({})'.format(num_string, den_string)
out = expression_parser(quot_string)
out.simplify_complete()
return out
if __name__ == '__main__':
print('TESTING EXPRESSIONS')
p1 = polynomial.polynomial_parser('mn+k^2')
f1 = factor.factorial(polynomial.polynomial_parser('n'))
p2 = polynomial.polynomial_parser('m^2n^2+k')
f2 = factor.factorial(polynomial.polynomial_parser('n+m'))
em1 = expression_mult([p1, f1])
em2 = expression_mult([p1, f2])
em3 = expression_mult([p2, f1])
em4 = expression_mult([p2, f2])
ea1 = expression_add([em1, em2])
ea2 = expression_add([em3, em4])
er1 = expression_rat(ea1, ea2)
p1.PRINT()
f1.PRINT()
p2.PRINT()
f2.PRINT()
em1.PRINT()
def test_get_common_factor(s1, s2):
print(
get_common_factor(polynomial.polynomial_parser(s1),
polynomial.polynomial_parser(s2), 'k'))
print('Numerator: {}\nDenominator: {}\n'.format(num.to_string(),
den.to_string()))
p, q, r = gosper.get_pqr(num, den, variable)
q, r, p = polynomial.polynomial_parser(
q.to_string()), polynomial.polynomial_parser(
r.to_string()), polynomial.polynomial_parser(p.to_string())
print('p: {}\nq: {}\nr: {}\n'.format(p.to_string(), q.to_string(),
r.to_string()))
f = get_f(p, q, r)
print('f: {}\n'.format(f if f == None else f.to_string()))
print('==============TRY ALGO ENDED================')
if __name__ == '__main__':
print('TESTING CONVERSIONS')
p1 = polynomial.polynomial_parser('1+xy+xy^2+x^2+y')
x = [1, 0, 1, 1, 1, 0, 0, 1, 0]
p2 = to_polynomial(x, 3, ['x', 'y'])
p1.PRINT()
p2.PRINT()
print(p1.equals(p2))
print(get_B(p1, 4, ['x', 'y']))
p1 = polynomial.polynomial_parser('1+k+k^2+ky+k^2y')
A = get_A(p1, p1, 4, 3, ['k', 'y'])
for a in A:
print('\t'.join(map(str, a)))
print('=====================================')
p = polynomial.polynomial_parser('2k-n-1')
q = polynomial.polynomial_parser('n+2-k')
r = polynomial.polynomial_parser('k')
A = get_A(q, r, 3, 2, ['k', 'n'])
