def d_catalan(dim,n): """d-dimensional Catalan numbers. The number of standard Young tableaux of shape (n^dim) = (n,..,n).""" res = sympy.factorial( dim * n ) for ell in range(0,dim): res /= sympy.ff(n+ell,n) return res
def test_binomial_rewrite(): n = Symbol("n", integer=True) k = Symbol("k", integer=True) assert binomial(n, k).rewrite(factorial) == factorial(n) / (factorial(k) * factorial(n - k)) assert binomial(n, k).rewrite(gamma) == gamma(n + 1) / (gamma(k + 1) * gamma(n - k + 1)) assert binomial(n, k).rewrite(ff) == ff(n, k) / factorial(k)
def test_rf_eval_apply(): x, y = symbols('x,y') n, k = symbols('n k', integer=True) m = Symbol('m', integer=True, nonnegative=True) assert rf(nan, y) == nan assert rf(x, nan) == nan assert rf(x, y) == rf(x, y) assert rf(oo, 0) == 1 assert rf(-oo, 0) == 1 assert rf(oo, 6) == oo assert rf(-oo, 7) == -oo assert rf(oo, -6) == oo assert rf(-oo, -7) == oo assert rf(x, 0) == 1 assert rf(x, 1) == x assert rf(x, 2) == x*(x + 1) assert rf(x, 3) == x*(x + 1)*(x + 2) assert rf(x, 5) == x*(x + 1)*(x + 2)*(x + 3)*(x + 4) assert rf(x, -1) == 1/(x - 1) assert rf(x, -2) == 1/((x - 1)*(x - 2)) assert rf(x, -3) == 1/((x - 1)*(x - 2)*(x - 3)) assert rf(1, 100) == factorial(100) assert rf(x**2 + 3*x, 2) == (x**2 + 3*x)*(x**2 + 3*x + 1) assert isinstance(rf(x**2 + 3*x, 2), Mul) assert rf(x**3 + x, -2) == 1/((x**3 + x - 1)*(x**3 + x - 2)) assert rf(Poly(x**2 + 3*x, x), 2) == Poly(x**4 + 8*x**3 + 19*x**2 + 12*x, x) assert isinstance(rf(Poly(x**2 + 3*x, x), 2), Poly) raises(ValueError, lambda: rf(Poly(x**2 + 3*x, x, y), 2)) assert rf(Poly(x**3 + x, x), -2) == 1/(x**6 - 9*x**5 + 35*x**4 - 75*x**3 + 94*x**2 - 66*x + 20) raises(ValueError, lambda: rf(Poly(x**3 + x, x, y), -2)) assert rf(x, m).is_integer is None assert rf(n, k).is_integer is None assert rf(n, m).is_integer is True assert rf(n, k + pi).is_integer is False assert rf(n, m + pi).is_integer is False assert rf(pi, m).is_integer is False assert rf(x, k).rewrite(ff) == ff(x + k - 1, k) assert rf(x, k).rewrite(binomial) == factorial(k)*binomial(x + k - 1, k) assert rf(n, k).rewrite(factorial) == \ factorial(n + k - 1) / factorial(n - 1) import random from mpmath import rf as mpmath_rf for i in range(100): x = -500 + 500 * random.random() k = -500 + 500 * random.random() assert (abs(mpmath_rf(x, k) - rf(x, k)) < 10**(-15))
def test_binomial_rewrite(): n = Symbol('n', integer=True) k = Symbol('k', integer=True) assert binomial(n, k).rewrite( factorial) == factorial(n)/(factorial(k)*factorial(n - k)) assert binomial( n, k).rewrite(gamma) == gamma(n + 1)/(gamma(k + 1)*gamma(n - k + 1)) assert binomial(n, k).rewrite(ff) == ff(n, k) / factorial(k)
def test_rf_ff_eval_hiprec(): maple = Float('6.9109401292234329956525265438452') us = ff(18, Rational(2, 3)).evalf(32) assert abs(us - maple) / us < 1e-31 maple = Float('6.8261540131125511557924466355367') us = rf(18, Rational(2, 3)).evalf(32) assert abs(us - maple) / us < 1e-31 maple = Float('34.007346127440197150854651814225') us = rf(Float('4.4', 32), Float('2.2', 32)) assert abs(us - maple) / us < 1e-31
def test_rf_ff_eval_hiprec(): maple = Float('6.9109401292234329956525265438452') us = ff(18, S(2)/3).evalf(32) assert abs(us - maple)/us < 1e-31 maple = Float('6.8261540131125511557924466355367') us = rf(18, S(2)/3).evalf(32) assert abs(us - maple)/us < 1e-31 maple = Float('34.007346127440197150854651814225') us = rf(Float('4.4', 32), Float('2.2', 32)); assert abs(us - maple)/us < 1e-31
def test_rf_eval_apply(): x, y = symbols('x,y') n, k = symbols('n k', integer=True) m = Symbol('m', integer=True, nonnegative=True) assert rf(nan, y) == nan assert rf(x, nan) == nan assert rf(x, y) == rf(x, y) assert rf(oo, 0) == 1 assert rf(-oo, 0) == 1 assert rf(oo, 6) == oo assert rf(-oo, 7) == -oo assert rf(oo, -6) == oo assert rf(-oo, -7) == oo assert rf(x, 0) == 1 assert rf(x, 1) == x assert rf(x, 2) == x * (x + 1) assert rf(x, 3) == x * (x + 1) * (x + 2) assert rf(x, 5) == x * (x + 1) * (x + 2) * (x + 3) * (x + 4) assert rf(x, -1) == 1 / (x - 1) assert rf(x, -2) == 1 / ((x - 1) * (x - 2)) assert rf(x, -3) == 1 / ((x - 1) * (x - 2) * (x - 3)) assert rf(1, 100) == factorial(100) assert rf(x**2 + 3 * x, 2) == x**4 + 8 * x**3 + 19 * x**2 + 12 * x assert rf(x**3 + x, -2) == 1 / (x**6 - 9 * x**5 + 35 * x**4 - 75 * x**3 + 94 * x**2 - 66 * x + 20) assert rf(x, m).is_integer is None assert rf(n, k).is_integer is None assert rf(n, m).is_integer is True assert rf(n, k + pi).is_integer is False assert rf(n, m + pi).is_integer is False assert rf(pi, m).is_integer is False assert rf(x, k).rewrite(ff) == ff(x + k - 1, k) assert rf(x, k).rewrite(binomial) == factorial(k) * binomial(x + k - 1, k) assert rf(n, k).rewrite(factorial) == \ factorial(n + k - 1) / factorial(n - 1)
def test_rf_eval_apply(): x, y = symbols('x,y') n, k = symbols('n k', integer=True) m = Symbol('m', integer=True, nonnegative=True) assert rf(nan, y) == nan assert rf(x, nan) == nan assert rf(x, y) == rf(x, y) assert rf(oo, 0) == 1 assert rf(-oo, 0) == 1 assert rf(oo, 6) == oo assert rf(-oo, 7) == -oo assert rf(oo, -6) == oo assert rf(-oo, -7) == oo assert rf(x, 0) == 1 assert rf(x, 1) == x assert rf(x, 2) == x*(x + 1) assert rf(x, 3) == x*(x + 1)*(x + 2) assert rf(x, 5) == x*(x + 1)*(x + 2)*(x + 3)*(x + 4) assert rf(x, -1) == 1/(x - 1) assert rf(x, -2) == 1/((x - 1)*(x - 2)) assert rf(x, -3) == 1/((x - 1)*(x - 2)*(x - 3)) assert rf(1, 100) == factorial(100) assert rf(x**2 + 3*x, 2) == x**4 + 8*x**3 + 19*x**2 + 12*x assert rf(x**3 + x, -2) == 1/(x**6 - 9*x**5 + 35*x**4 - 75*x**3 + 94*x**2 - 66*x + 20) assert rf(x, m).is_integer is None assert rf(n, k).is_integer is None assert rf(n, m).is_integer is True assert rf(n, k + pi).is_integer is False assert rf(n, m + pi).is_integer is False assert rf(pi, m).is_integer is False assert rf(x, k).rewrite(ff) == ff(x + k - 1, k) assert rf(x, k).rewrite(binomial) == factorial(k)*binomial(x + k - 1, k) assert rf(n, k).rewrite(factorial) == \ factorial(n + k - 1) / factorial(n - 1)
def _getWnXc(reactants): """ Get w(n;Xc). (This is used for displaying propensities only) :param dict reactants: reactant compartments Xc as a dictionary that maps Compartment to number of occurrences :return: w(n;Xc) """ def _n(content): """ Expression for number of compartments with given content """ if content.func == Compartment: return _n(content.args[0]) return Function('n', integer=True)(content) def _kronecker(content1, content2): if content1.func == Compartment: return _kronecker(content1.args[0], content2) if content2.func == Compartment: return _kronecker(content1, content2.args[0]) return KroneckerDelta(content1, content2) if len(reactants) == 0: return 1 elif len(reactants) == 1: (compartment, count) = next(iter(reactants.items())) __checkSimpleCompartment(compartment) return 1 / factorial(count) * ff(_n(compartment), count) elif len(reactants) == 2: i = iter(reactants.items()) (compartment1, count1) = next(i) (compartment2, count2) = next(i) __checkSimpleCompartment(compartment1) __checkSimpleCompartment(compartment2) if count1 != 1 or count2 != 1: raise RuntimeError( "Higher than 2nd order transitions are not implemented yet") return _n(compartment1) * (_n(compartment2) - _kronecker(compartment1, compartment2)) \ / (1 + _kronecker(compartment1, compartment2)) else: raise RuntimeError( "Higher than 2nd order transitions are not implemented yet")
def P(l: int, m: int, w=sym.Symbol('w')): r''' Same as associated Legendre functions, but expanded the derivative expression. sym.ff is the permutation number. sym.binomial is the combination number. $$ \frac{\mathrm d^{l+\left\vert m\right\vert}} {\mathrm dw^{l+\left\vert m\right\vert}} =\sum\limits_{j=\frac{l+\left\vert m\right\vert +\mathrm{Mod}\left(l+\left\vert m\right\vert,2\right)}2} ^l\mathrm C_l^jP_{2j}^{l+\left\vert m\right\vert} w^{2j-\left(l+\left\vert m\right\vert\right)} $$ ''' ans = 0. tmp = l + sym.functions.elementary.complexes.Abs(m) for j in range((tmp + tmp % 2) // 2, l + 1): ans += (sym.binomial(l, j) * sym.ff(2 * j, tmp) * w**(2 * j - tmp)) ans *= (1 - w**2)**(sym.functions.elementary.complexes.Abs(m) / 2) ans /= 2**l * sym.factorial(l) return ans
def test_ff_eval_apply(): x, y = symbols('x,y') n, k = symbols('n k', integer=True) m = Symbol('m', integer=True, nonnegative=True) assert ff(nan, y) is nan assert ff(x, nan) is nan assert unchanged(ff, x, y) assert ff(oo, 0) == 1 assert ff(-oo, 0) == 1 assert ff(oo, 6) is oo assert ff(-oo, 7) is -oo assert ff(-oo, 6) is oo assert ff(oo, -6) is oo assert ff(-oo, -7) is oo assert ff(x, 0) == 1 assert ff(x, 1) == x assert ff(x, 2) == x*(x - 1) assert ff(x, 3) == x*(x - 1)*(x - 2) assert ff(x, 5) == x*(x - 1)*(x - 2)*(x - 3)*(x - 4) assert ff(x, -1) == 1/(x + 1) assert ff(x, -2) == 1/((x + 1)*(x + 2)) assert ff(x, -3) == 1/((x + 1)*(x + 2)*(x + 3)) assert ff(100, 100) == factorial(100) assert ff(2*x**2 - 5*x, 2) == (2*x**2 - 5*x)*(2*x**2 - 5*x - 1) assert isinstance(ff(2*x**2 - 5*x, 2), Mul) assert ff(x**2 + 3*x, -2) == 1/((x**2 + 3*x + 1)*(x**2 + 3*x + 2)) assert ff(Poly(2*x**2 - 5*x, x), 2) == Poly(4*x**4 - 28*x**3 + 59*x**2 - 35*x, x) assert isinstance(ff(Poly(2*x**2 - 5*x, x), 2), Poly) raises(ValueError, lambda: ff(Poly(2*x**2 - 5*x, x, y), 2)) assert ff(Poly(x**2 + 3*x, x), -2) == 1/(x**4 + 12*x**3 + 49*x**2 + 78*x + 40) raises(ValueError, lambda: ff(Poly(x**2 + 3*x, x, y), -2)) assert ff(x, m).is_integer is None assert ff(n, k).is_integer is None assert ff(n, m).is_integer is True assert ff(n, k + pi).is_integer is False assert ff(n, m + pi).is_integer is False assert ff(pi, m).is_integer is False assert isinstance(ff(x, x), ff) assert ff(n, n) == factorial(n) def check(x, k, o, n): a, b = Dummy(), Dummy() r = lambda x, k: o(a, b).rewrite(n).subs({a:x,b:k}) for i in range(-5,5): for j in range(-5,5): assert o(i, j) == r(i, j), (o, n) check(x, k, ff, rf) check(x, k, ff, gamma) check(n, k, ff, factorial) check(x, k, ff, binomial) check(x, y, ff, factorial) check(x, y, ff, binomial) assert ff(x, k).rewrite(rf) == rf(x - k + 1, k) assert ff(x, k).rewrite(gamma) == Piecewise( (gamma(x + 1)/gamma(-k + x + 1), x >= 0), ((-1)**k*gamma(k - x)/gamma(-x), True)) assert ff(5, k).rewrite(gamma) == 120/gamma(6 - k) assert ff(n, k).rewrite(factorial) == Piecewise( (factorial(n)/factorial(-k + n), n >= 0), ((-1)**k*factorial(k - n - 1)/factorial(-n - 1), True)) assert ff(5, k).rewrite(factorial) == 120/factorial(5 - k) assert ff(x, k).rewrite(binomial) == factorial(k) * binomial(x, k) assert ff(x, y).rewrite(factorial) == ff(x, y) assert ff(x, y).rewrite(binomial) == ff(x, y) import random from mpmath import ff as mpmath_ff for i in range(100): x = -500 + 500 * random.random() k = -500 + 500 * random.random() a = mpmath_ff(x, k) b = ff(x, k) assert (abs(a - b) < abs(a) * 10**(-15))
def test_ff_eval_apply(): x, y = symbols('x,y') assert ff(nan, y) == nan assert ff(x, y) == ff(x, y) assert ff(oo, 0) == 1 assert ff(-oo, 0) == 1 assert ff(oo, 6) == oo assert ff(-oo, 7) == -oo assert ff(oo, -6) == oo assert ff(-oo, -7) == oo assert ff(x, 0) == 1 assert ff(x, 1) == x assert ff(x, 2) == x*(x - 1) assert ff(x, 3) == x*(x - 1)*(x - 2) assert ff(x, 5) == x*(x - 1)*(x - 2)*(x - 3)*(x - 4) assert ff(x, -1) == 1/(x + 1) assert ff(x, -2) == 1/((x + 1)*(x + 2)) assert ff(x, -3) == 1/((x + 1)*(x + 2)*(x + 3)) assert ff(100, 100) == factorial(100)
def test_ff_eval_apply(): x, y = symbols('x,y') assert ff(nan, y) == nan assert ff(x, y) == ff(x, y) assert ff(oo, 0) == 1 assert ff(-oo, 0) == 1 assert ff(oo, 6) == oo assert ff(-oo, 7) == -oo assert ff(oo, -6) == oo assert ff(-oo, -7) == oo assert ff(x, 0) == 1 assert ff(x, 1) == x assert ff(x, 2) == x * (x - 1) assert ff(x, 3) == x * (x - 1) * (x - 2) assert ff(x, 5) == x * (x - 1) * (x - 2) * (x - 3) * (x - 4) assert ff(x, -1) == 1 / (x + 1) assert ff(x, -2) == 1 / ((x + 1) * (x + 2)) assert ff(x, -3) == 1 / ((x + 1) * (x + 2) * (x + 3)) assert ff(100, 100) == factorial(100) assert ff(2 * x**2 - 5 * x, 2) == 4 * x**4 - 28 * x**3 + 59 * x**2 - 35 * x assert ff(x**2 + 3 * x, -2) == 1 / (x**4 + 12 * x**3 + 49 * x**2 + 78 * x + 40) n = Symbol('n', integer=True) k = Symbol('k', integer=True) m = Symbol('m', integer=True, nonnegative=True) assert ff(x, m).is_integer is None assert ff(n, k).is_integer is None assert ff(n, m).is_integer is True assert ff(n, k + pi).is_integer is False assert ff(n, m + pi).is_integer is False assert ff(pi, m).is_integer is False
def test_ff_eval_apply(): x, y = symbols('x,y') n, k = symbols('n k', integer=True) m = Symbol('m', integer=True, nonnegative=True) assert ff(nan, y) == nan assert ff(x, nan) == nan assert ff(x, y) == ff(x, y) assert ff(oo, 0) == 1 assert ff(-oo, 0) == 1 assert ff(oo, 6) == oo assert ff(-oo, 7) == -oo assert ff(oo, -6) == oo assert ff(-oo, -7) == oo assert ff(x, 0) == 1 assert ff(x, 1) == x assert ff(x, 2) == x*(x - 1) assert ff(x, 3) == x*(x - 1)*(x - 2) assert ff(x, 5) == x*(x - 1)*(x - 2)*(x - 3)*(x - 4) assert ff(x, -1) == 1/(x + 1) assert ff(x, -2) == 1/((x + 1)*(x + 2)) assert ff(x, -3) == 1/((x + 1)*(x + 2)*(x + 3)) assert ff(100, 100) == factorial(100) assert ff(2*x**2 - 5*x, 2) == 4*x**4 - 28*x**3 + 59*x**2 - 35*x assert ff(x**2 + 3*x, -2) == 1/(x**4 + 12*x**3 + 49*x**2 + 78*x + 40) assert ff(x, m).is_integer is None assert ff(n, k).is_integer is None assert ff(n, m).is_integer is True assert ff(n, k + pi).is_integer is False assert ff(n, m + pi).is_integer is False assert ff(pi, m).is_integer is False assert isinstance(ff(x, x), ff) assert ff(n, n) == factorial(n) assert ff(x, k).rewrite(rf) == rf(x - k + 1, k) assert ff(x, k).rewrite(gamma) == (-1)**k*gamma(k - x) / gamma(-x) assert ff(n, k).rewrite(factorial) == factorial(n) / factorial(n - k) assert ff(x, k).rewrite(binomial) == factorial(k) * binomial(x, k)
def Stirling_polynomial(n, z): 'Stirling_polynomial(n, z) = Stirling[z, z-n]/fall(z, n+1), for [int n>0]' assert n > 0 r = Stirling_circle_tail(n, z) / ff(z, n + 1) return gcd_terms(factor(r.simplify()))
def test_ff_eval_apply(): x, y = symbols('x,y') assert ff(nan, y) == nan assert ff(x, y) == ff(x, y) assert ff(oo, 0) == 1 assert ff(-oo, 0) == 1 assert ff(oo, 6) == oo assert ff(-oo, 7) == -oo assert ff(oo, -6) == oo assert ff(-oo, -7) == oo assert ff(x, 0) == 1 assert ff(x, 1) == x assert ff(x, 2) == x*(x - 1) assert ff(x, 3) == x*(x - 1)*(x - 2) assert ff(x, 5) == x*(x - 1)*(x - 2)*(x - 3)*(x - 4) assert ff(x, -1) == 1/(x + 1) assert ff(x, -2) == 1/((x + 1)*(x + 2)) assert ff(x, -3) == 1/((x + 1)*(x + 2)*(x + 3)) assert ff(100, 100) == factorial(100) n = Symbol('n', integer=True) k = Symbol('k', integer=True) m = Symbol('m', integer=True, nonnegative=True) assert ff(x, m).is_integer is None assert ff(n, k).is_integer is None assert ff(n, m).is_integer is True assert ff(n, k + pi).is_integer is False assert ff(n, m + pi).is_integer is False assert ff(pi, m).is_integer is False
def test_ff_eval_apply(): x, y = symbols('x,y') n, k = symbols('n k', integer=True) m = Symbol('m', integer=True, nonnegative=True) assert ff(nan, y) is nan assert ff(x, nan) is nan assert unchanged(ff, x, y) assert ff(oo, 0) == 1 assert ff(-oo, 0) == 1 assert ff(oo, 6) is oo assert ff(-oo, 7) is -oo assert ff(-oo, 6) is oo assert ff(oo, -6) is oo assert ff(-oo, -7) is oo assert ff(x, 0) == 1 assert ff(x, 1) == x assert ff(x, 2) == x * (x - 1) assert ff(x, 3) == x * (x - 1) * (x - 2) assert ff(x, 5) == x * (x - 1) * (x - 2) * (x - 3) * (x - 4) assert ff(x, -1) == 1 / (x + 1) assert ff(x, -2) == 1 / ((x + 1) * (x + 2)) assert ff(x, -3) == 1 / ((x + 1) * (x + 2) * (x + 3)) assert ff(100, 100) == factorial(100) assert ff(2 * x**2 - 5 * x, 2) == (2 * x**2 - 5 * x) * (2 * x**2 - 5 * x - 1) assert isinstance(ff(2 * x**2 - 5 * x, 2), Mul) assert ff(x**2 + 3 * x, -2) == 1 / ((x**2 + 3 * x + 1) * (x**2 + 3 * x + 2)) assert ff(Poly(2 * x**2 - 5 * x, x), 2) == Poly(4 * x**4 - 28 * x**3 + 59 * x**2 - 35 * x, x) assert isinstance(ff(Poly(2 * x**2 - 5 * x, x), 2), Poly) raises(ValueError, lambda: ff(Poly(2 * x**2 - 5 * x, x, y), 2)) assert ff(Poly(x**2 + 3 * x, x), -2) == 1 / (x**4 + 12 * x**3 + 49 * x**2 + 78 * x + 40) raises(ValueError, lambda: ff(Poly(x**2 + 3 * x, x, y), -2)) assert ff(x, m).is_integer is None assert ff(n, k).is_integer is None assert ff(n, m).is_integer is True assert ff(n, k + pi).is_integer is False assert ff(n, m + pi).is_integer is False assert ff(pi, m).is_integer is False assert isinstance(ff(x, x), ff) assert ff(n, n) == factorial(n) assert ff(x, k).rewrite(rf) == rf(x - k + 1, k) assert ff(x, k).rewrite(gamma) == (-1)**k * gamma(k - x) / gamma(-x) assert ff(n, k).rewrite(factorial) == factorial(n) / factorial(n - k) assert ff(x, k).rewrite(binomial) == factorial(k) * binomial(x, k) assert ff(x, y).rewrite(factorial) == ff(x, y) assert ff(x, y).rewrite(binomial) == ff(x, y) import random from mpmath import ff as mpmath_ff for i in range(100): x = -500 + 500 * random.random() k = -500 + 500 * random.random() assert (abs(mpmath_ff(x, k) - ff(x, k)) < 10**(-15))
def Stirling_subset_polynomial(n, z): 'Stirling_polynomial(n, z) = Stirling{z, z-n}/fall(z, n+1), for [int n>0]' assert n > 0 r = Stirling_subset_tail(n, z) / ff(z, n + 1) return gcd_terms(factor(r.simplify()))
t = lambda _k = 0: ans.subs(k, _k).doit() print(ans) for i in range(5): print('S(k={k}, z, n) = {s}'.format(k=i, s=t(i))) elif 0: t = lambda _k = 0: q.subs(k, _k).doit() print(q) for i in range(5): print('S(k={k}, 1-z, n) = {s}'.format(k=i, s=t(i))) elif 0: #T d z = sum z**i C(i,d) {~i} ## test = k ## ans = test.subs(k,k-1) ## print(ans) ## assert ans == k-1 T = Sum(ff(i,k) * z**i, (i,0,n)) K = T - ff(n,k)*z**n + k*z* T.subs(k,k-1) #ans = K.doit() fail for i in range(1,5): a = K.subs(n,i).doit().expand(force=True) print(a) elif 0: print(Sum(1,(i,0,n-1)).doit()) T = Sum((-1)**(n-j) * C(j,k), (j,0,n-1)) T2 = T.subs(n, 2*n) T3 = T.subs(n,2*n+1) print(T2) print(T3) for i in range(0,5): D = -2*factorial(i) a2 = T2.subs(k,i).doit().simplify() #.expand(force=True)
def test_ff_eval_apply(): x, y = symbols('x,y') assert ff(nan, y) == nan assert ff(x, y) == ff(x, y) assert ff(oo, 0) == 1 assert ff(-oo, 0) == 1 assert ff(oo, 6) == oo assert ff(-oo, 7) == -oo assert ff(oo, -6) == oo assert ff(-oo, -7) == oo assert ff(x, 0) == 1 assert ff(x, 1) == x assert ff(x, 2) == x * (x - 1) assert ff(x, 3) == x * (x - 1) * (x - 2) assert ff(x, 5) == x * (x - 1) * (x - 2) * (x - 3) * (x - 4) assert ff(x, -1) == 1 / (x + 1) assert ff(x, -2) == 1 / ((x + 1) * (x + 2)) assert ff(x, -3) == 1 / ((x + 1) * (x + 2) * (x + 3)) assert ff(100, 100) == factorial(100)
def test_rf_eval_apply(): x, y = symbols('x,y') n, k = symbols('n k', integer=True) m = Symbol('m', integer=True, nonnegative=True) assert rf(nan, y) is nan assert rf(x, nan) is nan assert unchanged(rf, x, y) assert rf(oo, 0) == 1 assert rf(-oo, 0) == 1 assert rf(oo, 6) is oo assert rf(-oo, 7) is -oo assert rf(-oo, 6) is oo assert rf(oo, -6) is oo assert rf(-oo, -7) is oo assert rf(-1, pi) == 0 assert rf(-5, 1 + I) == 0 assert unchanged(rf, -3, k) assert unchanged(rf, x, Symbol('k', integer=False)) assert rf(-3, Symbol('k', integer=False)) == 0 assert rf(Symbol('x', negative=True, integer=True), Symbol('k', integer=False)) == 0 assert rf(x, 0) == 1 assert rf(x, 1) == x assert rf(x, 2) == x*(x + 1) assert rf(x, 3) == x*(x + 1)*(x + 2) assert rf(x, 5) == x*(x + 1)*(x + 2)*(x + 3)*(x + 4) assert rf(x, -1) == 1/(x - 1) assert rf(x, -2) == 1/((x - 1)*(x - 2)) assert rf(x, -3) == 1/((x - 1)*(x - 2)*(x - 3)) assert rf(1, 100) == factorial(100) assert rf(x**2 + 3*x, 2) == (x**2 + 3*x)*(x**2 + 3*x + 1) assert isinstance(rf(x**2 + 3*x, 2), Mul) assert rf(x**3 + x, -2) == 1/((x**3 + x - 1)*(x**3 + x - 2)) assert rf(Poly(x**2 + 3*x, x), 2) == Poly(x**4 + 8*x**3 + 19*x**2 + 12*x, x) assert isinstance(rf(Poly(x**2 + 3*x, x), 2), Poly) raises(ValueError, lambda: rf(Poly(x**2 + 3*x, x, y), 2)) assert rf(Poly(x**3 + x, x), -2) == 1/(x**6 - 9*x**5 + 35*x**4 - 75*x**3 + 94*x**2 - 66*x + 20) raises(ValueError, lambda: rf(Poly(x**3 + x, x, y), -2)) assert rf(x, m).is_integer is None assert rf(n, k).is_integer is None assert rf(n, m).is_integer is True assert rf(n, k + pi).is_integer is False assert rf(n, m + pi).is_integer is False assert rf(pi, m).is_integer is False def check(x, k, o, n): a, b = Dummy(), Dummy() r = lambda x, k: o(a, b).rewrite(n).subs({a:x,b:k}) for i in range(-5,5): for j in range(-5,5): assert o(i, j) == r(i, j), (o, n, i, j) check(x, k, rf, ff) check(x, k, rf, binomial) check(n, k, rf, factorial) check(x, y, rf, factorial) check(x, y, rf, binomial) assert rf(x, k).rewrite(ff) == ff(x + k - 1, k) assert rf(x, k).rewrite(gamma) == Piecewise( (gamma(k + x)/gamma(x), x > 0), ((-1)**k*gamma(1 - x)/gamma(-k - x + 1), True)) assert rf(5, k).rewrite(gamma) == gamma(k + 5)/24 assert rf(x, k).rewrite(binomial) == factorial(k)*binomial(x + k - 1, k) assert rf(n, k).rewrite(factorial) == Piecewise( (factorial(k + n - 1)/factorial(n - 1), n > 0), ((-1)**k*factorial(-n)/factorial(-k - n), True)) assert rf(5, k).rewrite(factorial) == factorial(k + 4)/24 assert rf(x, y).rewrite(factorial) == rf(x, y) assert rf(x, y).rewrite(binomial) == rf(x, y) import random from mpmath import rf as mpmath_rf for i in range(100): x = -500 + 500 * random.random() k = -500 + 500 * random.random() assert (abs(mpmath_rf(x, k) - rf(x, k)) < 10**(-15))
def test_ff_eval_apply(): x, y = symbols('x,y') n, k = symbols('n k', integer=True) m = Symbol('m', integer=True, nonnegative=True) assert ff(nan, y) == nan assert ff(x, nan) == nan assert ff(x, y) == ff(x, y) assert ff(oo, 0) == 1 assert ff(-oo, 0) == 1 assert ff(oo, 6) == oo assert ff(-oo, 7) == -oo assert ff(oo, -6) == oo assert ff(-oo, -7) == oo assert ff(x, 0) == 1 assert ff(x, 1) == x assert ff(x, 2) == x*(x - 1) assert ff(x, 3) == x*(x - 1)*(x - 2) assert ff(x, 5) == x*(x - 1)*(x - 2)*(x - 3)*(x - 4) assert ff(x, -1) == 1/(x + 1) assert ff(x, -2) == 1/((x + 1)*(x + 2)) assert ff(x, -3) == 1/((x + 1)*(x + 2)*(x + 3)) assert ff(100, 100) == factorial(100) assert ff(2*x**2 - 5*x, 2) == (2*x**2 - 5*x)*(2*x**2 - 5*x - 1) assert isinstance(ff(2*x**2 - 5*x, 2), Mul) assert ff(x**2 + 3*x, -2) == 1/((x**2 + 3*x + 1)*(x**2 + 3*x + 2)) assert ff(Poly(2*x**2 - 5*x, x), 2) == Poly(4*x**4 - 28*x**3 + 59*x**2 - 35*x, x) assert isinstance(ff(Poly(2*x**2 - 5*x, x), 2), Poly) raises(ValueError, lambda: ff(Poly(2*x**2 - 5*x, x, y), 2)) assert ff(Poly(x**2 + 3*x, x), -2) == 1/(x**4 + 12*x**3 + 49*x**2 + 78*x + 40) raises(ValueError, lambda: ff(Poly(x**2 + 3*x, x, y), -2)) assert ff(x, m).is_integer is None assert ff(n, k).is_integer is None assert ff(n, m).is_integer is True assert ff(n, k + pi).is_integer is False assert ff(n, m + pi).is_integer is False assert ff(pi, m).is_integer is False assert isinstance(ff(x, x), ff) assert ff(n, n) == factorial(n) assert ff(x, k).rewrite(rf) == rf(x - k + 1, k) assert ff(x, k).rewrite(gamma) == (-1)**k*gamma(k - x) / gamma(-x) assert ff(n, k).rewrite(factorial) == factorial(n) / factorial(n - k) assert ff(x, k).rewrite(binomial) == factorial(k) * binomial(x, k)
def ffx(degree, step, z): return step**degree * ff(z / step, degree)