Table of contents: Definitions - Main formulas - Integral representations - Hypergeometric representations - Symmetry - Integer parameters - Recurrence relations
Fungrim symbol | Notation | Short description |
---|---|---|
BetaFunction | B(a,b) | Beta function |
Entry(ID("1c46fa"), SymbolDefinition(BetaFunction, BetaFunction(a, b), "Beta function"))
Fungrim symbol | Notation | Short description |
---|---|---|
IncompleteBeta | Bx(a,b) | Incomplete beta function |
Entry(ID("795fe5"), SymbolDefinition(IncompleteBeta, IncompleteBeta(x, a, b), "Incomplete beta function"))
Fungrim symbol | Notation | Short description |
---|---|---|
IncompleteBetaRegularized | Ix(a,b) | Regularized incomplete beta function |
Entry(ID("6bd011"), SymbolDefinition(IncompleteBetaRegularized, IncompleteBetaRegularized(x, a, b), "Regularized incomplete beta function"))
\mathrm{B}\!\left(a, b\right) = \frac{\Gamma(a) \Gamma(b)}{\Gamma\!\left(a + b\right)} a \in \mathbb{C} \setminus \{0, -1, \ldots\} \;\mathbin{\operatorname{and}}\; b \in \mathbb{C} \setminus \{0, -1, \ldots\}
Fungrim symbol | Notation | Short description |
---|---|---|
BetaFunction | B(a,b) | Beta function |
Gamma | Γ(z) | Gamma function |
CC | C | Complex numbers |
ZZLessEqual | Z≤n | Integers less than or equal to n |
Entry(ID("888581"), Formula(Equal(BetaFunction(a, b), Div(Mul(Gamma(a), Gamma(b)), Gamma(Add(a, b))))), Variables(a, b), Assumptions(And(Element(a, SetMinus(CC, ZZLessEqual(0))), Element(b, SetMinus(CC, ZZLessEqual(0))))))
I_{x}\!\left(a, b\right) = \frac{\mathrm{B}_{x}\!\left(a, b\right)}{\mathrm{B}\!\left(a, b\right)} x \in \mathbb{C} \;\mathbin{\operatorname{and}}\; a \in \mathbb{C} \setminus \{0, -1, \ldots\} \;\mathbin{\operatorname{and}}\; b \in \mathbb{C} \setminus \{0, -1, \ldots\} \;\mathbin{\operatorname{and}}\; a + b \notin \{0, -1, \ldots\}
Fungrim symbol | Notation | Short description |
---|---|---|
IncompleteBetaRegularized | Ix(a,b) | Regularized incomplete beta function |
IncompleteBeta | Bx(a,b) | Incomplete beta function |
BetaFunction | B(a,b) | Beta function |
CC | C | Complex numbers |
ZZLessEqual | Z≤n | Integers less than or equal to n |
Entry(ID("c92da4"), Formula(Equal(IncompleteBetaRegularized(x, a, b), Div(IncompleteBeta(x, a, b), BetaFunction(a, b)))), Variables(x, a, b), Assumptions(And(Element(x, CC), Element(a, SetMinus(CC, ZZLessEqual(0))), Element(b, SetMinus(CC, ZZLessEqual(0))), NotElement(Add(a, b), ZZLessEqual(0)))))
\mathrm{B}_{0}\!\left(a, b\right) = 0 a \in \mathbb{C} \setminus \{0, -1, \ldots\} \;\mathbin{\operatorname{and}}\; b \in \mathbb{C} \setminus \{0, -1, \ldots\}
Fungrim symbol | Notation | Short description |
---|---|---|
IncompleteBeta | Bx(a,b) | Incomplete beta function |
CC | C | Complex numbers |
ZZLessEqual | Z≤n | Integers less than or equal to n |
Entry(ID("ba7baf"), Formula(Equal(IncompleteBeta(0, a, b), 0)), Variables(a, b), Assumptions(And(Element(a, SetMinus(CC, ZZLessEqual(0))), Element(b, SetMinus(CC, ZZLessEqual(0))))))
\mathrm{B}_{1}\!\left(a, b\right) = \mathrm{B}\!\left(a, b\right) a \in \mathbb{C} \setminus \{0, -1, \ldots\} \;\mathbin{\operatorname{and}}\; b \in \mathbb{C} \setminus \{0, -1, \ldots\}
Fungrim symbol | Notation | Short description |
---|---|---|
IncompleteBeta | Bx(a,b) | Incomplete beta function |
BetaFunction | B(a,b) | Beta function |
CC | C | Complex numbers |
ZZLessEqual | Z≤n | Integers less than or equal to n |
Entry(ID("3141e4"), Formula(Equal(IncompleteBeta(1, a, b), BetaFunction(a, b))), Variables(a, b), Assumptions(And(Element(a, SetMinus(CC, ZZLessEqual(0))), Element(b, SetMinus(CC, ZZLessEqual(0))))))
I_{0}\!\left(a, b\right) = 0 x \in \mathbb{C} \;\mathbin{\operatorname{and}}\; a \in \mathbb{C} \setminus \{0, -1, \ldots\} \;\mathbin{\operatorname{and}}\; b \in \mathbb{C} \setminus \{0, -1, \ldots\} \;\mathbin{\operatorname{and}}\; a + b \notin \{0, -1, \ldots\}
Fungrim symbol | Notation | Short description |
---|---|---|
IncompleteBetaRegularized | Ix(a,b) | Regularized incomplete beta function |
CC | C | Complex numbers |
ZZLessEqual | Z≤n | Integers less than or equal to n |
Entry(ID("ff613a"), Formula(Equal(IncompleteBetaRegularized(0, a, b), 0)), Variables(x, a, b), Assumptions(And(Element(x, CC), Element(a, SetMinus(CC, ZZLessEqual(0))), Element(b, SetMinus(CC, ZZLessEqual(0))), NotElement(Add(a, b), ZZLessEqual(0)))))
I_{1}\!\left(a, b\right) = 1 x \in \mathbb{C} \;\mathbin{\operatorname{and}}\; a \in \mathbb{C} \setminus \{0, -1, \ldots\} \;\mathbin{\operatorname{and}}\; b \in \mathbb{C} \setminus \{0, -1, \ldots\} \;\mathbin{\operatorname{and}}\; a + b \notin \{0, -1, \ldots\}
Fungrim symbol | Notation | Short description |
---|---|---|
IncompleteBetaRegularized | Ix(a,b) | Regularized incomplete beta function |
CC | C | Complex numbers |
ZZLessEqual | Z≤n | Integers less than or equal to n |
Entry(ID("6bcfa6"), Formula(Equal(IncompleteBetaRegularized(1, a, b), 1)), Variables(x, a, b), Assumptions(And(Element(x, CC), Element(a, SetMinus(CC, ZZLessEqual(0))), Element(b, SetMinus(CC, ZZLessEqual(0))), NotElement(Add(a, b), ZZLessEqual(0)))))
\mathrm{B}\!\left(a, b\right) = \int_{0}^{1} {t}^{a - 1} {\left(1 - t\right)}^{b - 1} \, dt a \in \mathbb{C} \;\mathbin{\operatorname{and}}\; b \in \mathbb{C} \;\mathbin{\operatorname{and}}\; \operatorname{Re}(a) > 0 \;\mathbin{\operatorname{and}}\; \operatorname{Re}(b) > 0
Fungrim symbol | Notation | Short description |
---|---|---|
BetaFunction | B(a,b) | Beta function |
Integral | ∫abf(x)dx | Integral |
Pow | ab | Power |
CC | C | Complex numbers |
Re | Re(z) | Real part |
Entry(ID("542cf7"), Formula(Equal(BetaFunction(a, b), Integral(Mul(Pow(t, Sub(a, 1)), Pow(Sub(1, t), Sub(b, 1))), For(t, 0, 1)))), Variables(a, b), Assumptions(And(Element(a, CC), Element(b, CC), Greater(Re(a), 0), Greater(Re(b), 0))))
\mathrm{B}\!\left(a, b\right) = 2 \int_{0}^{\pi / 2} \sin^{2 a - 1}\!\left(t\right) \cos^{2 b - 1}\!\left(t\right) \, dt a \in \mathbb{C} \;\mathbin{\operatorname{and}}\; b \in \mathbb{C} \;\mathbin{\operatorname{and}}\; \operatorname{Re}(a) > 0 \;\mathbin{\operatorname{and}}\; \operatorname{Re}(b) > 0
Fungrim symbol | Notation | Short description |
---|---|---|
BetaFunction | B(a,b) | Beta function |
Integral | ∫abf(x)dx | Integral |
Pow | ab | Power |
Sin | sin(z) | Sine |
Cos | cos(z) | Cosine |
Pi | π | The constant pi (3.14...) |
CC | C | Complex numbers |
Re | Re(z) | Real part |
Entry(ID("48910b"), Formula(Equal(BetaFunction(a, b), Mul(2, Integral(Mul(Pow(Sin(t), Sub(Mul(2, a), 1)), Pow(Cos(t), Sub(Mul(2, b), 1))), For(t, 0, Div(Pi, 2)))))), Variables(a, b), Assumptions(And(Element(a, CC), Element(b, CC), Greater(Re(a), 0), Greater(Re(b), 0))))
\mathrm{B}_{x}\!\left(a, b\right) = \int_{0}^{x} {t}^{a - 1} {\left(1 - t\right)}^{b - 1} \, dt x \in \left[0, 1\right] \;\mathbin{\operatorname{and}}\; a \in \mathbb{C} \;\mathbin{\operatorname{and}}\; b \in \mathbb{C} \;\mathbin{\operatorname{and}}\; \operatorname{Re}(a) > 0 \;\mathbin{\operatorname{and}}\; \operatorname{Re}(b) > 0
Fungrim symbol | Notation | Short description |
---|---|---|
IncompleteBeta | Bx(a,b) | Incomplete beta function |
Integral | ∫abf(x)dx | Integral |
Pow | ab | Power |
ClosedInterval | [a,b] | Closed interval |
CC | C | Complex numbers |
Re | Re(z) | Real part |
Entry(ID("3e08b6"), Formula(Equal(IncompleteBeta(x, a, b), Integral(Mul(Pow(t, Sub(a, 1)), Pow(Sub(1, t), Sub(b, 1))), For(t, 0, x)))), Variables(x, a, b), Assumptions(And(Element(x, ClosedInterval(0, 1)), Element(a, CC), Element(b, CC), Greater(Re(a), 0), Greater(Re(b), 0))))
I_{x}\!\left(a, b\right) = \frac{1}{\mathrm{B}\!\left(a, b\right)} \int_{0}^{x} {t}^{a - 1} {\left(1 - t\right)}^{b - 1} \, dt x \in \left[0, 1\right] \;\mathbin{\operatorname{and}}\; a \in \mathbb{C} \;\mathbin{\operatorname{and}}\; b \in \mathbb{C} \;\mathbin{\operatorname{and}}\; \operatorname{Re}(a) > 0 \;\mathbin{\operatorname{and}}\; \operatorname{Re}(b) > 0
Fungrim symbol | Notation | Short description |
---|---|---|
IncompleteBetaRegularized | Ix(a,b) | Regularized incomplete beta function |
BetaFunction | B(a,b) | Beta function |
Integral | ∫abf(x)dx | Integral |
Pow | ab | Power |
ClosedInterval | [a,b] | Closed interval |
CC | C | Complex numbers |
Re | Re(z) | Real part |
Entry(ID("a1941b"), Formula(Equal(IncompleteBetaRegularized(x, a, b), Mul(Div(1, BetaFunction(a, b)), Integral(Mul(Pow(t, Sub(a, 1)), Pow(Sub(1, t), Sub(b, 1))), For(t, 0, x))))), Variables(x, a, b), Assumptions(And(Element(x, ClosedInterval(0, 1)), Element(a, CC), Element(b, CC), Greater(Re(a), 0), Greater(Re(b), 0))))
\mathrm{B}_{x}\!\left(a, b\right) = \frac{{x}^{a}}{a} \,{}_2F_1\!\left(a, 1 - b, a + 1, x\right) a \in \mathbb{C} \setminus \{0, -1, \ldots\} \;\mathbin{\operatorname{and}}\; b \in \mathbb{C} \;\mathbin{\operatorname{and}}\; x \in \mathbb{C} \setminus \left\{1\right\} \;\mathbin{\operatorname{and}}\; \left(x \ne 0 \;\mathbin{\operatorname{or}}\; \operatorname{Re}(a) > 0\right)
Fungrim symbol | Notation | Short description |
---|---|---|
IncompleteBeta | Bx(a,b) | Incomplete beta function |
Pow | ab | Power |
Hypergeometric2F1 | 2F1(a,b,c,z) | Gauss hypergeometric function |
CC | C | Complex numbers |
ZZLessEqual | Z≤n | Integers less than or equal to n |
Re | Re(z) | Real part |
Entry(ID("5ec9c0"), Formula(Equal(IncompleteBeta(x, a, b), Mul(Div(Pow(x, a), a), Hypergeometric2F1(a, Sub(1, b), Add(a, 1), x)))), Variables(x, a, b), Assumptions(And(Element(a, SetMinus(CC, ZZLessEqual(0))), Element(b, CC), Element(x, SetMinus(CC, Set(1))), Or(NotEqual(x, 0), Greater(Re(a), 0)))))
\mathrm{B}\!\left(a, b\right) = \mathrm{B}\!\left(b, a\right) a \in \mathbb{C} \setminus \{0, -1, \ldots\} \;\mathbin{\operatorname{and}}\; b \in \mathbb{C} \setminus \{0, -1, \ldots\}
Fungrim symbol | Notation | Short description |
---|---|---|
BetaFunction | B(a,b) | Beta function |
CC | C | Complex numbers |
ZZLessEqual | Z≤n | Integers less than or equal to n |
Entry(ID("cc2ebb"), Formula(Equal(BetaFunction(a, b), BetaFunction(b, a))), Variables(a, b), Assumptions(And(Element(a, SetMinus(CC, ZZLessEqual(0))), Element(b, SetMinus(CC, ZZLessEqual(0))))))
I_{x}\!\left(a, b\right) = 1 - I_{1 - x}\!\left(b, a\right) x \in \mathbb{C} \;\mathbin{\operatorname{and}}\; a \in \mathbb{C} \setminus \{0, -1, \ldots\} \;\mathbin{\operatorname{and}}\; b \in \mathbb{C} \setminus \{0, -1, \ldots\} \;\mathbin{\operatorname{and}}\; a + b \notin \{0, -1, \ldots\}
Fungrim symbol | Notation | Short description |
---|---|---|
IncompleteBetaRegularized | Ix(a,b) | Regularized incomplete beta function |
CC | C | Complex numbers |
ZZLessEqual | Z≤n | Integers less than or equal to n |
Entry(ID("315b3d"), Formula(Equal(IncompleteBetaRegularized(x, a, b), Sub(1, IncompleteBetaRegularized(Sub(1, x), b, a)))), Variables(a, b, x), Assumptions(And(Element(x, CC), Element(a, SetMinus(CC, ZZLessEqual(0))), Element(b, SetMinus(CC, ZZLessEqual(0))), NotElement(Add(a, b), ZZLessEqual(0)))))
\mathrm{B}\!\left(a, b\right) \mathrm{B}\!\left(a + b, c\right) = \mathrm{B}\!\left(b, c\right) \mathrm{B}\!\left(a, b + c\right) a \in \mathbb{C} \setminus \{0, -1, \ldots\} \;\mathbin{\operatorname{and}}\; b \in \mathbb{C} \setminus \{0, -1, \ldots\} \;\mathbin{\operatorname{and}}\; c \in \mathbb{C} \setminus \{0, -1, \ldots\} \;\mathbin{\operatorname{and}}\; a + b \notin \{0, -1, \ldots\} \;\mathbin{\operatorname{and}}\; b + c \notin \{0, -1, \ldots\}
Fungrim symbol | Notation | Short description |
---|---|---|
BetaFunction | B(a,b) | Beta function |
CC | C | Complex numbers |
ZZLessEqual | Z≤n | Integers less than or equal to n |
Entry(ID("fd0e48"), Formula(Equal(Mul(BetaFunction(a, b), BetaFunction(Add(a, b), c)), Mul(BetaFunction(b, c), BetaFunction(a, Add(b, c))))), Variables(a, b, c), Assumptions(And(Element(a, SetMinus(CC, ZZLessEqual(0))), Element(b, SetMinus(CC, ZZLessEqual(0))), Element(c, SetMinus(CC, ZZLessEqual(0))), NotElement(Add(a, b), ZZLessEqual(0)), NotElement(Add(b, c), ZZLessEqual(0)))))
\mathrm{B}\!\left(m, n\right) = \frac{\left(m - 1\right)! \left(n - 1\right)!}{\left(m + n - 1\right)!} m \in \mathbb{Z}_{\ge 1} \;\mathbin{\operatorname{and}}\; n \in \mathbb{Z}_{\ge 1}
Fungrim symbol | Notation | Short description |
---|---|---|
BetaFunction | B(a,b) | Beta function |
Factorial | n! | Factorial |
ZZGreaterEqual | Z≥n | Integers greater than or equal to n |
Entry(ID("082a69"), Formula(Equal(BetaFunction(m, n), Div(Mul(Factorial(Sub(m, 1)), Factorial(Sub(n, 1))), Factorial(Sub(Add(m, n), 1))))), Variables(m, n), Assumptions(And(Element(m, ZZGreaterEqual(1)), Element(n, ZZGreaterEqual(1)))))
\mathrm{B}\!\left(m, n\right) = \frac{1}{m {m + n - 1 \choose m}} m \in \mathbb{Z}_{\ge 1} \;\mathbin{\operatorname{and}}\; n \in \mathbb{Z}_{\ge 1}
Fungrim symbol | Notation | Short description |
---|---|---|
BetaFunction | B(a,b) | Beta function |
Binomial | (kn) | Binomial coefficient |
ZZGreaterEqual | Z≥n | Integers greater than or equal to n |
Entry(ID("bb4f41"), Formula(Equal(BetaFunction(m, n), Div(1, Mul(m, Binomial(Sub(Add(m, n), 1), m))))), Variables(m, n), Assumptions(And(Element(m, ZZGreaterEqual(1)), Element(n, ZZGreaterEqual(1)))))
\mathrm{B}\!\left(n, b\right) = \begin{cases} {\tilde \infty}, & -b \in \{0, 1, \ldots, n - 1\}\\\frac{1}{n {n + b - 1 \choose n}}, & \text{otherwise}\\ \end{cases} n \in \mathbb{Z}_{\ge 1} \;\mathbin{\operatorname{and}}\; b \in \mathbb{C}
Fungrim symbol | Notation | Short description |
---|---|---|
BetaFunction | B(a,b) | Beta function |
UnsignedInfinity | ∞~ | Unsigned infinity |
Range | {a,a+1,…,b} | Integers between given endpoints |
Binomial | (kn) | Binomial coefficient |
ZZGreaterEqual | Z≥n | Integers greater than or equal to n |
CC | C | Complex numbers |
Entry(ID("72db94"), Formula(Equal(BetaFunction(n, b), Cases(Tuple(UnsignedInfinity, Element(Neg(b), Range(0, Sub(n, 1)))), Tuple(Div(1, Mul(n, Binomial(Sub(Add(n, b), 1), n))), Otherwise)))), Variables(n, b), Assumptions(And(Element(n, ZZGreaterEqual(1)), Element(b, CC))))
\mathrm{B}\!\left(-n, b\right) = \begin{cases} \frac{{\left(-1\right)}^{b}}{b {n \choose b}}, & b \in \{1, 2, \ldots, n\}\\{\tilde \infty}, & \text{otherwise}\\ \end{cases} n \in \mathbb{Z}_{\ge 0} \;\mathbin{\operatorname{and}}\; b \in \mathbb{C}
Fungrim symbol | Notation | Short description |
---|---|---|
BetaFunction | B(a,b) | Beta function |
Pow | ab | Power |
Binomial | (kn) | Binomial coefficient |
Range | {a,a+1,…,b} | Integers between given endpoints |
UnsignedInfinity | ∞~ | Unsigned infinity |
ZZGreaterEqual | Z≥n | Integers greater than or equal to n |
CC | C | Complex numbers |
Entry(ID("a7dbf6"), Formula(Equal(BetaFunction(Neg(n), b), Cases(Tuple(Div(Pow(-1, b), Mul(b, Binomial(n, b))), Element(b, Range(1, n))), Tuple(UnsignedInfinity, Otherwise)))), Variables(n, b), Assumptions(And(Element(n, ZZGreaterEqual(0)), Element(b, CC))))
\mathop{\operatorname{res}}\limits_{z=a} \mathrm{B}\!\left(z, b\right) = \begin{cases} {n - b \choose n}, & n \in \mathbb{Z}_{\ge 0}\\0, & \text{otherwise}\\ \end{cases}\; \text{ where } n = -a a \in \mathbb{C} \;\mathbin{\operatorname{and}}\; b \in \mathbb{C} \setminus \{0, -1, \ldots\}
Fungrim symbol | Notation | Short description |
---|---|---|
Residue | z=cresf(z) | Complex residue |
BetaFunction | B(a,b) | Beta function |
Binomial | (kn) | Binomial coefficient |
ZZGreaterEqual | Z≥n | Integers greater than or equal to n |
CC | C | Complex numbers |
ZZLessEqual | Z≤n | Integers less than or equal to n |
Entry(ID("1f72e9"), Formula(Equal(Residue(BetaFunction(z, b), For(z, a)), Where(Cases(Tuple(Binomial(Sub(n, b), n), Element(n, ZZGreaterEqual(0))), Tuple(0, Otherwise)), Equal(n, Neg(a))))), Variables(a, b), Assumptions(And(Element(a, CC), Element(b, SetMinus(CC, ZZLessEqual(0))))))
\left(a + b\right) \mathrm{B}\!\left(a + 1, b\right) = a \mathrm{B}\!\left(a, b\right) a \in \mathbb{C} \setminus \{0, -1, \ldots\} \;\mathbin{\operatorname{and}}\; b \in \mathbb{C} \setminus \{0, -1, \ldots\}
Fungrim symbol | Notation | Short description |
---|---|---|
BetaFunction | B(a,b) | Beta function |
CC | C | Complex numbers |
ZZLessEqual | Z≤n | Integers less than or equal to n |
Entry(ID("bdea17"), Formula(Equal(Mul(Add(a, b), BetaFunction(Add(a, 1), b)), Mul(a, BetaFunction(a, b)))), Variables(a, b), Assumptions(And(Element(a, SetMinus(CC, ZZLessEqual(0))), Element(b, SetMinus(CC, ZZLessEqual(0))))))
\mathrm{B}\!\left(a, b\right) = \mathrm{B}\!\left(a + 1, b\right) + \mathrm{B}\!\left(a, b + 1\right) a \in \mathbb{C} \setminus \{0, -1, \ldots\} \;\mathbin{\operatorname{and}}\; b \in \mathbb{C} \setminus \{0, -1, \ldots\}
Fungrim symbol | Notation | Short description |
---|---|---|
BetaFunction | B(a,b) | Beta function |
CC | C | Complex numbers |
ZZLessEqual | Z≤n | Integers less than or equal to n |
Entry(ID("e9f966"), Formula(Equal(BetaFunction(a, b), Add(BetaFunction(Add(a, 1), b), BetaFunction(a, Add(b, 1))))), Variables(a, b), Assumptions(And(Element(a, SetMinus(CC, ZZLessEqual(0))), Element(b, SetMinus(CC, ZZLessEqual(0))))))
Copyright (C) Fredrik Johansson and contributors. Fungrim is provided under the MIT license. The source code is on GitHub.
2021-03-15 19:12:00.328586 UTC