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| Meta Title | 18.1 Beta Distribution | Stan Functions Reference |
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| Boilerpipe Text | Probability Density Function
If
α
∈
R
+
and
β
∈
R
+
, then for
θ
∈
(
0
,
1
)
,
Beta
(
θ
|
α
,
β
)
=
1
B
(
α
,
β
)
θ
α
−
1
(
1
−
θ
)
β
−
1
,
where the beta function
B
(
)
is as
defined in section
combinatorial functions
.
Warning:
If
θ
=
0
or
θ
=
1
, then the probability
is 0 and the log probability is
−
∞
. Similarly, the
distribution requires strictly positive parameters,
α
,
β
>
0
.
Sampling Statement
theta ~
beta
(alpha, beta)
Increment target log probability density with
beta_lpdf(theta | alpha, beta)
dropping constant additive terms.
Stan Functions
real
beta_lpdf
(reals theta | reals alpha, reals beta)
The log of the beta density of
theta
in
[
0
,
1
]
given positive prior
successes (plus one) alpha and prior failures (plus one) beta
real
beta_cdf
(reals theta, reals alpha, reals beta)
The beta cumulative distribution function of
theta
in
[
0
,
1
]
given
positive prior successes (plus one) alpha and prior failures (plus
one) beta
real
beta_lcdf
(reals theta | reals alpha, reals beta)
The log of the beta cumulative distribution function of
theta
in
[
0
,
1
]
given positive prior successes (plus one) alpha and prior
failures (plus one) beta
real
beta_lccdf
(reals theta | reals alpha, reals beta)
The log of the beta complementary cumulative distribution function of
theta
in
[
0
,
1
]
given positive prior successes (plus one) alpha and
prior failures (plus one) beta
R
beta_rng
(reals alpha, reals beta)
Generate a beta variate with positive prior successes (plus one) alpha
and prior failures (plus one) beta; may only be used in transformed data and
generated quantities blocks. For a description of argument and return types, see
section
vectorized PRNG functions
. |
| Markdown | - [Stan Functions Reference](https://mc-stan.org/docs/functions-reference/index.html)
- [*Overview*](https://mc-stan.org/docs/2_22/functions-reference/index.html#overview)
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- [*Built-In Functions*](https://mc-stan.org/docs/2_22/functions-reference/built-in-functions.html#built-in-functions)
- [**1** Void Functions](https://mc-stan.org/docs/2_22/functions-reference/void-functions.html)
- [**1\.1** Print Statement](https://mc-stan.org/docs/2_22/functions-reference/print-statement.html)
- [**1\.2** Reject Statement](https://mc-stan.org/docs/2_22/functions-reference/reject-statement.html)
- [**2** Integer-Valued Basic Functions](https://mc-stan.org/docs/2_22/functions-reference/integer-valued-basic-functions.html)
- [**2\.1** Integer-Valued Arithmetic Operators](https://mc-stan.org/docs/2_22/functions-reference/int-arithmetic.html)
- [**2\.1.1** Binary Infix Operators](https://mc-stan.org/docs/2_22/functions-reference/int-arithmetic.html#binary-infix-operators)
- [**2\.1.2** Unary Prefix Operators](https://mc-stan.org/docs/2_22/functions-reference/int-arithmetic.html#unary-prefix-operators)
- [**2\.2** Absolute Functions](https://mc-stan.org/docs/2_22/functions-reference/absolute-functions.html)
- [**2\.3** Bound Functions](https://mc-stan.org/docs/2_22/functions-reference/bound-functions.html)
- [**3** Real-Valued Basic Functions](https://mc-stan.org/docs/2_22/functions-reference/real-valued-basic-functions.html)
- [**3\.1** Vectorization of Real-Valued Functions](https://mc-stan.org/docs/2_22/functions-reference/fun-vectorization.html)
- [**3\.1.1** Unary Function Vectorization](https://mc-stan.org/docs/2_22/functions-reference/fun-vectorization.html#unary-function-vectorization)
- [**3\.2** Mathematical Constants](https://mc-stan.org/docs/2_22/functions-reference/built-in-constants.html)
- [**3\.3** Special Values](https://mc-stan.org/docs/2_22/functions-reference/special-values.html)
- [**3\.4** Log Probability Function](https://mc-stan.org/docs/2_22/functions-reference/get-log-prob.html)
- [**3\.5** Logical Functions](https://mc-stan.org/docs/2_22/functions-reference/logical-functions.html)
- [**3\.5.1** Comparison Operators](https://mc-stan.org/docs/2_22/functions-reference/logical-functions.html#comparison-operators)
- [**3\.5.2** Boolean Operators](https://mc-stan.org/docs/2_22/functions-reference/logical-functions.html#boolean-operators)
- [**3\.5.3** Logical Functions](https://mc-stan.org/docs/2_22/functions-reference/logical-functions.html#logical-functions-1)
- [**3\.6** Real-Valued Arithmetic Operators](https://mc-stan.org/docs/2_22/functions-reference/real-valued-arithmetic-operators.html)
- [**3\.6.1** Binary Infix Operators](https://mc-stan.org/docs/2_22/functions-reference/real-valued-arithmetic-operators.html#binary-infix-operators-1)
- [**3\.6.2** Unary Prefix Operators](https://mc-stan.org/docs/2_22/functions-reference/real-valued-arithmetic-operators.html#unary-prefix-operators-1)
- [**3\.7** Step-like Functions](https://mc-stan.org/docs/2_22/functions-reference/step-functions.html)
- [**3\.7.1** Absolute Value Functions](https://mc-stan.org/docs/2_22/functions-reference/step-functions.html#absolute-value-functions)
- [**3\.7.2** Bounds Functions](https://mc-stan.org/docs/2_22/functions-reference/step-functions.html#bounds-functions)
- [**3\.7.3** Arithmetic Functions](https://mc-stan.org/docs/2_22/functions-reference/step-functions.html#arithmetic-functions)
- [**3\.7.4** Rounding Functions](https://mc-stan.org/docs/2_22/functions-reference/step-functions.html#rounding-functions)
- [**3\.8** Power and Logarithm Functions](https://mc-stan.org/docs/2_22/functions-reference/power-and-logarithm-functions.html)
- [**3\.9** Trigonometric Functions](https://mc-stan.org/docs/2_22/functions-reference/trigonometric-functions.html)
- [**3\.10** Hyperbolic Trigonometric Functions](https://mc-stan.org/docs/2_22/functions-reference/hyperbolic-trigonometric-functions.html)
- [**3\.11** Link Functions](https://mc-stan.org/docs/2_22/functions-reference/link-functions.html)
- [**3\.12** Probability-Related Functions](https://mc-stan.org/docs/2_22/functions-reference/Phi-function.html)
- [**3\.12.1** Normal Cumulative Distribution Functions](https://mc-stan.org/docs/2_22/functions-reference/Phi-function.html#normal-cumulative-distribution-functions)
- [**3\.12.2** Other Probability-Related Functions](https://mc-stan.org/docs/2_22/functions-reference/Phi-function.html#other-probability-related-functions)
- [**3\.13** Combinatorial Functions](https://mc-stan.org/docs/2_22/functions-reference/betafun.html)
- [**3\.14** Composed Functions](https://mc-stan.org/docs/2_22/functions-reference/composed-functions.html)
- [**4** Array Operations](https://mc-stan.org/docs/2_22/functions-reference/array-operations.html)
- [**4\.1** Reductions](https://mc-stan.org/docs/2_22/functions-reference/array-reductions.html)
- [**4\.1.1** Minimum and Maximum](https://mc-stan.org/docs/2_22/functions-reference/array-reductions.html#minimum-and-maximum)
- [**4\.1.2** Sum, Product, and Log Sum of Exp](https://mc-stan.org/docs/2_22/functions-reference/array-reductions.html#sum-product-and-log-sum-of-exp)
- [**4\.1.3** Sample Mean, Variance, and Standard Deviation](https://mc-stan.org/docs/2_22/functions-reference/array-reductions.html#sample-mean-variance-and-standard-deviation)
- [**4\.1.4** Euclidean Distance and Squared Distance](https://mc-stan.org/docs/2_22/functions-reference/array-reductions.html#euclidean-distance-and-squared-distance)
- [**4\.2** Array Size and Dimension Function](https://mc-stan.org/docs/2_22/functions-reference/array-size-and-dimension-function.html)
- [**4\.3** Array Broadcasting](https://mc-stan.org/docs/2_22/functions-reference/array-broadcasting.html)
- [**4\.4** Array Concatenation](https://mc-stan.org/docs/2_22/functions-reference/array-concatenation.html)
- [**4\.5** Sorting functions](https://mc-stan.org/docs/2_22/functions-reference/sorting-functions.html)
- [**5** Matrix Operations](https://mc-stan.org/docs/2_22/functions-reference/matrix-operations.html)
- [**5\.1** Integer-Valued Matrix Size Functions](https://mc-stan.org/docs/2_22/functions-reference/integer-valued-matrix-size-functions.html)
- [**5\.2** Matrix Arithmetic Operators](https://mc-stan.org/docs/2_22/functions-reference/matrix-arithmetic-operators.html)
- [**5\.2.1** Negation Prefix Operators](https://mc-stan.org/docs/2_22/functions-reference/matrix-arithmetic-operators.html#negation-prefix-operators)
- [**5\.2.2** Infix Matrix Operators](https://mc-stan.org/docs/2_22/functions-reference/matrix-arithmetic-operators.html#infix-matrix-operators)
- [**5\.2.3** Broadcast Infix Operators](https://mc-stan.org/docs/2_22/functions-reference/matrix-arithmetic-operators.html#broadcast-infix-operators)
- [**5\.2.4** Elementwise Arithmetic Operations](https://mc-stan.org/docs/2_22/functions-reference/matrix-arithmetic-operators.html#elementwise-arithmetic-operations)
- [**5\.3** Transposition Operator](https://mc-stan.org/docs/2_22/functions-reference/transposition-operator.html)
- [**5\.4** Elementwise Functions](https://mc-stan.org/docs/2_22/functions-reference/elementwise-functions.html)
- [**5\.5** Dot Products and Specialized Products](https://mc-stan.org/docs/2_22/functions-reference/dot-products-and-specialized-products.html)
- [**5\.5.1** Specialized Products](https://mc-stan.org/docs/2_22/functions-reference/dot-products-and-specialized-products.html#specialized-products)
- [**5\.6** Reductions](https://mc-stan.org/docs/2_22/functions-reference/reductions.html)
- [**5\.6.1** Log Sum of Exponents](https://mc-stan.org/docs/2_22/functions-reference/reductions.html#log-sum-of-exponents)
- [**5\.6.2** Minimum and Maximum](https://mc-stan.org/docs/2_22/functions-reference/reductions.html#minimum-and-maximum-1)
- [**5\.6.3** Sums and Products](https://mc-stan.org/docs/2_22/functions-reference/reductions.html#sums-and-products)
- [**5\.6.4** Sample Moments](https://mc-stan.org/docs/2_22/functions-reference/reductions.html#sample-moments)
- [**5\.7** Broadcast Functions](https://mc-stan.org/docs/2_22/functions-reference/matrix-broadcast.html)
- [**5\.8** Diagonal Matrix Functions](https://mc-stan.org/docs/2_22/functions-reference/diagonal-matrix-functions.html)
- [**5\.9** Slicing and Blocking Functions](https://mc-stan.org/docs/2_22/functions-reference/slicing-and-blocking-functions.html)
- [**5\.9.1** Columns and Rows](https://mc-stan.org/docs/2_22/functions-reference/slicing-and-blocking-functions.html#columns-and-rows)
- [**5\.9.2** Block Operations](https://mc-stan.org/docs/2_22/functions-reference/slicing-and-blocking-functions.html#block-operations)
- [**5\.10** Matrix Concatenation](https://mc-stan.org/docs/2_22/functions-reference/matrix-concatenation.html)
- [**5\.10.0.1** Horizontal concatenation](https://mc-stan.org/docs/2_22/functions-reference/matrix-concatenation.html#horizontal-concatenation)
- [**5\.10.0.2** Vertical concatenation](https://mc-stan.org/docs/2_22/functions-reference/matrix-concatenation.html#vertical-concatenation)
- [**5\.11** Special Matrix Functions](https://mc-stan.org/docs/2_22/functions-reference/softmax.html)
- [**5\.11.1** Softmax](https://mc-stan.org/docs/2_22/functions-reference/softmax.html#softmax-1)
- [**5\.11.2** Cumulative Sums](https://mc-stan.org/docs/2_22/functions-reference/softmax.html#cumulative-sums)
- [**5\.12** Covariance Functions](https://mc-stan.org/docs/2_22/functions-reference/covariance.html)
- [**5\.12.1** Exponentiated quadratic covariance function](https://mc-stan.org/docs/2_22/functions-reference/covariance.html#exponentiated-quadratic-covariance-function)
- [**5\.13** Linear Algebra Functions and Solvers](https://mc-stan.org/docs/2_22/functions-reference/linear-algebra-functions-and-solvers.html)
- [**5\.13.1** Matrix Division Operators and Functions](https://mc-stan.org/docs/2_22/functions-reference/linear-algebra-functions-and-solvers.html#matrix-division-operators-and-functions)
- [**5\.13.2** Symmetric positive-definite matrix division functions](https://mc-stan.org/docs/2_22/functions-reference/linear-algebra-functions-and-solvers.html#symmetric-positive-definite-matrix-division-functions)
- [**5\.13.3** Matrix Exponential](https://mc-stan.org/docs/2_22/functions-reference/linear-algebra-functions-and-solvers.html#matrix-exponential)
- [**5\.13.4** Linear Algebra Functions](https://mc-stan.org/docs/2_22/functions-reference/linear-algebra-functions-and-solvers.html#linear-algebra-functions)
- [**5\.14** Sort Functions](https://mc-stan.org/docs/2_22/functions-reference/sort-functions.html)
- [**6** Sparse Matrix Operations](https://mc-stan.org/docs/2_22/functions-reference/sparse-matrices.html)
- [**6\.1** Compressed Row Storage](https://mc-stan.org/docs/2_22/functions-reference/CSR.html)
- [**6\.2** Conversion Functions](https://mc-stan.org/docs/2_22/functions-reference/conversion-functions.html)
- [**6\.2.1** Dense to Sparse Conversion](https://mc-stan.org/docs/2_22/functions-reference/conversion-functions.html#dense-to-sparse-conversion)
- [**6\.2.2** Sparse to Dense Conversion](https://mc-stan.org/docs/2_22/functions-reference/conversion-functions.html#sparse-to-dense-conversion)
- [**6\.3** Sparse Matrix Arithmetic](https://mc-stan.org/docs/2_22/functions-reference/sparse-matrix-arithmetic.html)
- [**6\.3.1** Sparse Matrix Multiplication](https://mc-stan.org/docs/2_22/functions-reference/sparse-matrix-arithmetic.html#sparse-matrix-multiplication)
- [**7** Mixed Operations](https://mc-stan.org/docs/2_22/functions-reference/mixed-operations.html)
- [**8** Compound Arithmetic and Assignment](https://mc-stan.org/docs/2_22/functions-reference/compound-arithmetic-and-assignment.html)
- [**8\.1** Compound Addition and Assignment](https://mc-stan.org/docs/2_22/functions-reference/compound-addition-and-assignment.html)
- [**8\.2** Compound Subtraction and Assignment](https://mc-stan.org/docs/2_22/functions-reference/compound-subtraction-and-assignment.html)
- [**8\.3** Compound Multiplication and Assignment](https://mc-stan.org/docs/2_22/functions-reference/compound-multiplication-and-assignment.html)
- [**8\.4** Compound Division and Assignment](https://mc-stan.org/docs/2_22/functions-reference/compound-division-and-assignment.html)
- [**8\.5** Compound Elementwise Multiplication and Assignment](https://mc-stan.org/docs/2_22/functions-reference/compound-elementwise-multiplication-and-assignment.html)
- [**8\.6** Compound Elementwise Division and Assignment](https://mc-stan.org/docs/2_22/functions-reference/compound-elementwise-division-and-assignment.html)
- [**9** Higher-Order Functions](https://mc-stan.org/docs/2_22/functions-reference/higher-order-functions.html)
- [**9\.1** Algebraic Equation Solver](https://mc-stan.org/docs/2_22/functions-reference/functions-algebraic-solver.html)
- [**9\.1.1** Specifying an Algebraic Equation as a Function](https://mc-stan.org/docs/2_22/functions-reference/functions-algebraic-solver.html#specifying-an-algebraic-equation-as-a-function)
- [**9\.1.2** Call to the Algebraic Solver](https://mc-stan.org/docs/2_22/functions-reference/functions-algebraic-solver.html#call-to-the-algebraic-solver)
- [**9\.2** Ordinary Differential Equation (ODE) Solvers](https://mc-stan.org/docs/2_22/functions-reference/functions-ode-solver.html)
- [**9\.2.1** Specifying an Ordinary Differential Equation as a Function](https://mc-stan.org/docs/2_22/functions-reference/functions-ode-solver.html#specifying-an-ordinary-differential-equation-as-a-function)
- [**9\.2.2** Non-Stiff Solver](https://mc-stan.org/docs/2_22/functions-reference/functions-ode-solver.html#non-stiff-solver)
- [**9\.2.3** Stiff Solver](https://mc-stan.org/docs/2_22/functions-reference/functions-ode-solver.html#stiff-solver)
- [**9\.2.4** Arguments to the ODE solvers](https://mc-stan.org/docs/2_22/functions-reference/functions-ode-solver.html#arguments-to-the-ode-solvers)
- [**9\.3** 1D Integrator](https://mc-stan.org/docs/2_22/functions-reference/functions-1d-integrator.html)
- [**9\.3.1** Specifying an Integrand as a Function](https://mc-stan.org/docs/2_22/functions-reference/functions-1d-integrator.html#specifying-an-integrand-as-a-function)
- [**9\.3.2** Call to the 1D Integrator](https://mc-stan.org/docs/2_22/functions-reference/functions-1d-integrator.html#call-to-the-1d-integrator)
- [**9\.4** Higher-Order Map](https://mc-stan.org/docs/2_22/functions-reference/functions-map.html)
- [**9\.4.1** Specifying the Mapped Function](https://mc-stan.org/docs/2_22/functions-reference/functions-map.html#specifying-the-mapped-function)
- [**9\.4.2** Rectangular Map](https://mc-stan.org/docs/2_22/functions-reference/functions-map.html#rectangular-map)
- [*Discrete Distributions*](https://mc-stan.org/docs/2_22/functions-reference/discrete-distributions.html#discrete-distributions)
- [**10** Conventions for Probability Functions](https://mc-stan.org/docs/2_22/functions-reference/conventions-for-probability-functions.html)
- [**10\.1** Suffix Marks Type of Function](https://mc-stan.org/docs/2_22/functions-reference/suffix-marks-type-of-function.html)
- [**10\.2** Argument Order and the Vertical Bar](https://mc-stan.org/docs/2_22/functions-reference/argument-order-and-the-vertical-bar.html)
- [**10\.3** Sampling Notation](https://mc-stan.org/docs/2_22/functions-reference/sampling-notation.html)
- [**10\.4** Finite Inputs](https://mc-stan.org/docs/2_22/functions-reference/finite-inputs.html)
- [**10\.5** Boundary Conditions](https://mc-stan.org/docs/2_22/functions-reference/boundary-conditions.html)
- [**10\.6** Pseudorandom Number Generators](https://mc-stan.org/docs/2_22/functions-reference/distributions-prng.html)
- [**10\.6.1** Restricted to Transformed Data and Generated Quantities](https://mc-stan.org/docs/2_22/functions-reference/distributions-prng.html#restricted-to-transformed-data-and-generated-quantities)
- [**10\.6.2** Limited Vectorization](https://mc-stan.org/docs/2_22/functions-reference/distributions-prng.html#limited-vectorization)
- [**10\.7** Cumulative Distribution Functions](https://mc-stan.org/docs/2_22/functions-reference/cumulative-distribution-functions.html)
- [**10\.8** Vectorization](https://mc-stan.org/docs/2_22/functions-reference/vectorization.html)
- [**10\.8.1** Vectorized Function Signatures](https://mc-stan.org/docs/2_22/functions-reference/vectorization.html#prob-vectorization)
- [**10\.8.2** Evaluating Vectorized Log Probability Functions](https://mc-stan.org/docs/2_22/functions-reference/vectorization.html#evaluating-vectorized-log-probability-functions)
- [**10\.8.3** Evaluating Vectorized PRNG Functions](https://mc-stan.org/docs/2_22/functions-reference/vectorization.html#prng-vectorization)
- [**11** Binary Distributions](https://mc-stan.org/docs/2_22/functions-reference/binary-distributions.html)
- [**11\.1** Bernoulli Distribution](https://mc-stan.org/docs/2_22/functions-reference/bernoulli-distribution.html)
- [**11\.1.1** Probability Mass Function](https://mc-stan.org/docs/2_22/functions-reference/bernoulli-distribution.html#probability-mass-function)
- [**11\.1.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/bernoulli-distribution.html#sampling-statement)
- [**11\.1.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/bernoulli-distribution.html#stan-functions)
- [**11\.2** Bernoulli Distribution, Logit Parameterization](https://mc-stan.org/docs/2_22/functions-reference/bernoulli-logit-distribution.html)
- [**11\.2.1** Probability Mass Function](https://mc-stan.org/docs/2_22/functions-reference/bernoulli-logit-distribution.html#probability-mass-function-1)
- [**11\.2.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/bernoulli-logit-distribution.html#sampling-statement-1)
- [**11\.2.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/bernoulli-logit-distribution.html#stan-functions-1)
- [**11\.3** Bernoulli-Logit Generalised Linear Model (Logistic Regression)](https://mc-stan.org/docs/2_22/functions-reference/bernoulli-logit-glm.html)
- [**11\.3.1** Probability Mass Function](https://mc-stan.org/docs/2_22/functions-reference/bernoulli-logit-glm.html#probability-mass-function-2)
- [**11\.3.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/bernoulli-logit-glm.html#sampling-statement-2)
- [**11\.3.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/bernoulli-logit-glm.html#stan-functions-2)
- [**12** Bounded Discrete Distributions](https://mc-stan.org/docs/2_22/functions-reference/bounded-discrete-distributions.html)
- [**12\.1** Binomial Distribution](https://mc-stan.org/docs/2_22/functions-reference/binomial-distribution.html)
- [**12\.1.1** Probability Mass Function](https://mc-stan.org/docs/2_22/functions-reference/binomial-distribution.html#probability-mass-function-3)
- [**12\.1.2** Log Probability Mass Function](https://mc-stan.org/docs/2_22/functions-reference/binomial-distribution.html#log-probability-mass-function)
- [**12\.1.3** Gradient of Log Probability Mass Function](https://mc-stan.org/docs/2_22/functions-reference/binomial-distribution.html#gradient-of-log-probability-mass-function)
- [**12\.1.4** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/binomial-distribution.html#sampling-statement-3)
- [**12\.1.5** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/binomial-distribution.html#stan-functions-3)
- [**12\.2** Binomial Distribution, Logit Parameterization](https://mc-stan.org/docs/2_22/functions-reference/binomial-distribution-logit-parameterization.html)
- [**12\.2.1** Probability Mass Function](https://mc-stan.org/docs/2_22/functions-reference/binomial-distribution-logit-parameterization.html#probability-mass-function-4)
- [**12\.2.2** Log Probability Mass Function](https://mc-stan.org/docs/2_22/functions-reference/binomial-distribution-logit-parameterization.html#log-probability-mass-function-1)
- [**12\.2.3** Gradient of Log Probability Mass Function](https://mc-stan.org/docs/2_22/functions-reference/binomial-distribution-logit-parameterization.html#gradient-of-log-probability-mass-function-1)
- [**12\.2.4** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/binomial-distribution-logit-parameterization.html#sampling-statement-4)
- [**12\.2.5** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/binomial-distribution-logit-parameterization.html#stan-functions-4)
- [**12\.3** Beta-Binomial Distribution](https://mc-stan.org/docs/2_22/functions-reference/beta-binomial-distribution.html)
- [**12\.3.1** Probability Mass Function](https://mc-stan.org/docs/2_22/functions-reference/beta-binomial-distribution.html#probability-mass-function-5)
- [**12\.3.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/beta-binomial-distribution.html#sampling-statement-5)
- [**12\.3.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/beta-binomial-distribution.html#stan-functions-5)
- [**12\.4** Hypergeometric Distribution](https://mc-stan.org/docs/2_22/functions-reference/hypergeometric-distribution.html)
- [**12\.4.1** Probability Mass Function](https://mc-stan.org/docs/2_22/functions-reference/hypergeometric-distribution.html#probability-mass-function-6)
- [**12\.4.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/hypergeometric-distribution.html#sampling-statement-6)
- [**12\.4.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/hypergeometric-distribution.html#stan-functions-6)
- [**12\.5** Categorical Distribution](https://mc-stan.org/docs/2_22/functions-reference/categorical-distribution.html)
- [**12\.5.1** Probability Mass Functions](https://mc-stan.org/docs/2_22/functions-reference/categorical-distribution.html#probability-mass-functions)
- [**12\.5.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/categorical-distribution.html#sampling-statement-7)
- [**12\.5.3** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/categorical-distribution.html#sampling-statement-8)
- [**12\.5.4** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/categorical-distribution.html#stan-functions-7)
- [**12\.6** Ordered Logistic Distribution](https://mc-stan.org/docs/2_22/functions-reference/ordered-logistic-distribution.html)
- [**12\.6.1** Probability Mass Function](https://mc-stan.org/docs/2_22/functions-reference/ordered-logistic-distribution.html#probability-mass-function-7)
- [**12\.6.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/ordered-logistic-distribution.html#sampling-statement-9)
- [**12\.6.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/ordered-logistic-distribution.html#stan-functions-8)
- [**12\.7** Ordered Probit Distribution](https://mc-stan.org/docs/2_22/functions-reference/ordered-probit-distribution.html)
- [**12\.7.1** Probability Mass Function](https://mc-stan.org/docs/2_22/functions-reference/ordered-probit-distribution.html#probability-mass-function-8)
- [**12\.7.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/ordered-probit-distribution.html#sampling-statement-10)
- [**12\.7.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/ordered-probit-distribution.html#stan-functions-9)
- [**13** Unbounded Discrete Distributions](https://mc-stan.org/docs/2_22/functions-reference/unbounded-discrete-distributions.html)
- [**13\.1** Negative Binomial Distribution](https://mc-stan.org/docs/2_22/functions-reference/negative-binomial-distribution.html)
- [**13\.1.1** Probability Mass Function](https://mc-stan.org/docs/2_22/functions-reference/negative-binomial-distribution.html#probability-mass-function-9)
- [**13\.1.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/negative-binomial-distribution.html#sampling-statement-11)
- [**13\.1.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/negative-binomial-distribution.html#stan-functions-10)
- [**13\.2** Negative Binomial Distribution (alternative parameterization)](https://mc-stan.org/docs/2_22/functions-reference/nbalt.html)
- [**13\.2.1** Probability Mass Function](https://mc-stan.org/docs/2_22/functions-reference/nbalt.html#probability-mass-function-10)
- [**13\.2.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/nbalt.html#sampling-statement-12)
- [**13\.2.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/nbalt.html#stan-functions-11)
- [**13\.3** Negative Binomial Distribution (log alternative parameterization)](https://mc-stan.org/docs/2_22/functions-reference/neg-binom-2-log.html)
- [**13\.3.1** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/neg-binom-2-log.html#sampling-statement-13)
- [**13\.3.2** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/neg-binom-2-log.html#stan-functions-12)
- [**13\.4** Negative-Binomial-2-Log Generalised Linear Model (Negative Binomial Regression)](https://mc-stan.org/docs/2_22/functions-reference/neg-binom-2-log-glm.html)
- [**13\.4.1** Probability Mass Function](https://mc-stan.org/docs/2_22/functions-reference/neg-binom-2-log-glm.html#probability-mass-function-11)
- [**13\.4.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/neg-binom-2-log-glm.html#sampling-statement-14)
- [**13\.4.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/neg-binom-2-log-glm.html#stan-functions-13)
- [**13\.5** Poisson Distribution](https://mc-stan.org/docs/2_22/functions-reference/poisson.html)
- [**13\.5.1** Probability Mass Function](https://mc-stan.org/docs/2_22/functions-reference/poisson.html#probability-mass-function-12)
- [**13\.5.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/poisson.html#sampling-statement-15)
- [**13\.5.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/poisson.html#stan-functions-14)
- [**13\.6** Poisson Distribution, Log Parameterization](https://mc-stan.org/docs/2_22/functions-reference/poisson-distribution-log-parameterization.html)
- [**13\.6.1** Probability Mass Function](https://mc-stan.org/docs/2_22/functions-reference/poisson-distribution-log-parameterization.html#probability-mass-function-13)
- [**13\.6.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/poisson-distribution-log-parameterization.html#sampling-statement-16)
- [**13\.6.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/poisson-distribution-log-parameterization.html#stan-functions-15)
- [**13\.7** Poisson-Log Generalised Linear Model (Poisson Regression)](https://mc-stan.org/docs/2_22/functions-reference/poisson-log-glm.html)
- [**13\.7.1** Probability Mass Function](https://mc-stan.org/docs/2_22/functions-reference/poisson-log-glm.html#probability-mass-function-14)
- [**13\.7.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/poisson-log-glm.html#sampling-statement-17)
- [**13\.7.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/poisson-log-glm.html#stan-functions-16)
- [**14** Multivariate Discrete Distributions](https://mc-stan.org/docs/2_22/functions-reference/multivariate-discrete-distributions.html)
- [**14\.1** Multinomial Distribution](https://mc-stan.org/docs/2_22/functions-reference/multinomial-distribution.html)
- [**14\.1.1** Probability Mass Function](https://mc-stan.org/docs/2_22/functions-reference/multinomial-distribution.html#probability-mass-function-15)
- [**14\.1.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/multinomial-distribution.html#sampling-statement-18)
- [**14\.1.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/multinomial-distribution.html#stan-functions-17)
- [*Continuous Distributions*](https://mc-stan.org/docs/2_22/functions-reference/continuous-distributions.html#continuous-distributions)
- [**15** Unbounded Continuous Distributions](https://mc-stan.org/docs/2_22/functions-reference/unbounded-continuous-distributions.html)
- [**15\.1** Normal Distribution](https://mc-stan.org/docs/2_22/functions-reference/normal-distribution.html)
- [**15\.1.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/normal-distribution.html#probability-density-function)
- [**15\.1.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/normal-distribution.html#sampling-statement-19)
- [**15\.1.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/normal-distribution.html#stan-functions-18)
- [**15\.1.4** Standard Normal Distribution](https://mc-stan.org/docs/2_22/functions-reference/normal-distribution.html#standard-normal-distribution)
- [**15\.1.5** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/normal-distribution.html#sampling-statement-20)
- [**15\.1.6** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/normal-distribution.html#stan-functions-19)
- [**15\.2** Normal-Id Generalised Linear Model (Linear Regression)](https://mc-stan.org/docs/2_22/functions-reference/normal-id-glm.html)
- [**15\.2.1** Probability Distribution Function](https://mc-stan.org/docs/2_22/functions-reference/normal-id-glm.html#probability-distribution-function)
- [**15\.2.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/normal-id-glm.html#sampling-statement-21)
- [**15\.2.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/normal-id-glm.html#stan-functions-20)
- [**15\.3** Exponentially Modified Normal Distribution](https://mc-stan.org/docs/2_22/functions-reference/exponentially-modified-normal-distribution.html)
- [**15\.3.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/exponentially-modified-normal-distribution.html#probability-density-function-1)
- [**15\.3.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/exponentially-modified-normal-distribution.html#sampling-statement-22)
- [**15\.3.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/exponentially-modified-normal-distribution.html#stan-functions-21)
- [**15\.4** Skew Normal Distribution](https://mc-stan.org/docs/2_22/functions-reference/skew-normal-distribution.html)
- [**15\.4.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/skew-normal-distribution.html#probability-density-function-2)
- [**15\.4.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/skew-normal-distribution.html#sampling-statement-23)
- [**15\.4.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/skew-normal-distribution.html#stan-functions-22)
- [**15\.5** Student-T Distribution](https://mc-stan.org/docs/2_22/functions-reference/student-t-distribution.html)
- [**15\.5.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/student-t-distribution.html#probability-density-function-3)
- [**15\.5.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/student-t-distribution.html#sampling-statement-24)
- [**15\.5.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/student-t-distribution.html#stan-functions-23)
- [**15\.6** Cauchy Distribution](https://mc-stan.org/docs/2_22/functions-reference/cauchy-distribution.html)
- [**15\.6.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/cauchy-distribution.html#probability-density-function-4)
- [**15\.6.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/cauchy-distribution.html#sampling-statement-25)
- [**15\.6.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/cauchy-distribution.html#stan-functions-24)
- [**15\.7** Double Exponential (Laplace) Distribution](https://mc-stan.org/docs/2_22/functions-reference/double-exponential-laplace-distribution.html)
- [**15\.7.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/double-exponential-laplace-distribution.html#probability-density-function-5)
- [**15\.7.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/double-exponential-laplace-distribution.html#sampling-statement-26)
- [**15\.7.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/double-exponential-laplace-distribution.html#stan-functions-25)
- [**15\.8** Logistic Distribution](https://mc-stan.org/docs/2_22/functions-reference/logistic-distribution.html)
- [**15\.8.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/logistic-distribution.html#probability-density-function-6)
- [**15\.8.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/logistic-distribution.html#sampling-statement-27)
- [**15\.8.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/logistic-distribution.html#stan-functions-26)
- [**15\.9** Gumbel Distribution](https://mc-stan.org/docs/2_22/functions-reference/gumbel-distribution.html)
- [**15\.9.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/gumbel-distribution.html#probability-density-function-7)
- [**15\.9.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/gumbel-distribution.html#sampling-statement-28)
- [**15\.9.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/gumbel-distribution.html#stan-functions-27)
- [**16** Positive Continuous Distributions](https://mc-stan.org/docs/2_22/functions-reference/positive-continuous-distributions.html)
- [**16\.1** Lognormal Distribution](https://mc-stan.org/docs/2_22/functions-reference/lognormal.html)
- [**16\.1.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/lognormal.html#probability-density-function-8)
- [**16\.1.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/lognormal.html#sampling-statement-29)
- [**16\.1.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/lognormal.html#stan-functions-28)
- [**16\.2** Chi-Square Distribution](https://mc-stan.org/docs/2_22/functions-reference/chi-square-distribution.html)
- [**16\.2.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/chi-square-distribution.html#probability-density-function-9)
- [**16\.2.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/chi-square-distribution.html#sampling-statement-30)
- [**16\.2.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/chi-square-distribution.html#stan-functions-29)
- [**16\.3** Inverse Chi-Square Distribution](https://mc-stan.org/docs/2_22/functions-reference/inverse-chi-square-distribution.html)
- [**16\.3.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/inverse-chi-square-distribution.html#probability-density-function-10)
- [**16\.3.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/inverse-chi-square-distribution.html#sampling-statement-31)
- [**16\.3.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/inverse-chi-square-distribution.html#stan-functions-30)
- [**16\.4** Scaled Inverse Chi-Square Distribution](https://mc-stan.org/docs/2_22/functions-reference/scaled-inverse-chi-square-distribution.html)
- [**16\.4.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/scaled-inverse-chi-square-distribution.html#probability-density-function-11)
- [**16\.4.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/scaled-inverse-chi-square-distribution.html#sampling-statement-32)
- [**16\.4.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/scaled-inverse-chi-square-distribution.html#stan-functions-31)
- [**16\.5** Exponential Distribution](https://mc-stan.org/docs/2_22/functions-reference/exponential-distribution.html)
- [**16\.5.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/exponential-distribution.html#probability-density-function-12)
- [**16\.5.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/exponential-distribution.html#sampling-statement-33)
- [**16\.5.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/exponential-distribution.html#stan-functions-32)
- [**16\.6** Gamma Distribution](https://mc-stan.org/docs/2_22/functions-reference/gamma-distribution.html)
- [**16\.6.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/gamma-distribution.html#probability-density-function-13)
- [**16\.6.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/gamma-distribution.html#sampling-statement-34)
- [**16\.6.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/gamma-distribution.html#stan-functions-33)
- [**16\.7** Inverse Gamma Distribution](https://mc-stan.org/docs/2_22/functions-reference/inverse-gamma-distribution.html)
- [**16\.7.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/inverse-gamma-distribution.html#probability-density-function-14)
- [**16\.7.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/inverse-gamma-distribution.html#sampling-statement-35)
- [**16\.7.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/inverse-gamma-distribution.html#stan-functions-34)
- [**16\.8** Weibull Distribution](https://mc-stan.org/docs/2_22/functions-reference/weibull-distribution.html)
- [**16\.8.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/weibull-distribution.html#probability-density-function-15)
- [**16\.8.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/weibull-distribution.html#sampling-statement-36)
- [**16\.8.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/weibull-distribution.html#stan-functions-35)
- [**16\.9** Frechet Distribution](https://mc-stan.org/docs/2_22/functions-reference/frechet-distribution.html)
- [**16\.9.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/frechet-distribution.html#probability-density-function-16)
- [**16\.9.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/frechet-distribution.html#sampling-statement-37)
- [**16\.9.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/frechet-distribution.html#stan-functions-36)
- [**16\.10** Rayleigh Distribution](https://mc-stan.org/docs/2_22/functions-reference/rayleigh-distribution.html)
- [**16\.10.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/rayleigh-distribution.html#probability-density-function-17)
- [**16\.10.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/rayleigh-distribution.html#sampling-statement-38)
- [**16\.10.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/rayleigh-distribution.html#stan-functions-37)
- [**17** Positive Lower-Bounded Distributions](https://mc-stan.org/docs/2_22/functions-reference/positive-lower-bounded-distributions.html)
- [**17\.1** Pareto Distribution](https://mc-stan.org/docs/2_22/functions-reference/pareto-distribution.html)
- [**17\.1.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/pareto-distribution.html#probability-density-function-18)
- [**17\.1.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/pareto-distribution.html#sampling-statement-39)
- [**17\.1.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/pareto-distribution.html#stan-functions-38)
- [**17\.2** Pareto Type 2 Distribution](https://mc-stan.org/docs/2_22/functions-reference/pareto-type-2-distribution.html)
- [**17\.2.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/pareto-type-2-distribution.html#probability-density-function-19)
- [**17\.2.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/pareto-type-2-distribution.html#sampling-statement-40)
- [**17\.2.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/pareto-type-2-distribution.html#stan-functions-39)
- [**17\.3** Wiener First Passage Time Distribution](https://mc-stan.org/docs/2_22/functions-reference/wiener-first-passage-time-distribution.html)
- [**17\.3.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/wiener-first-passage-time-distribution.html#probability-density-function-20)
- [**17\.3.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/wiener-first-passage-time-distribution.html#sampling-statement-41)
- [**17\.3.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/wiener-first-passage-time-distribution.html#stan-functions-40)
- [**17\.3.4** Boundaries](https://mc-stan.org/docs/2_22/functions-reference/wiener-first-passage-time-distribution.html#boundaries)
- [**18** Continuous Distributions on \[0, 1\]](https://mc-stan.org/docs/2_22/functions-reference/continuous-distributions-on-0-1.html)
- [**18\.1** Beta Distribution](https://mc-stan.org/docs/2_22/functions-reference/beta-distribution.html)
- [**18\.1.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/beta-distribution.html#probability-density-function-21)
- [**18\.1.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/beta-distribution.html#sampling-statement-42)
- [**18\.1.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/beta-distribution.html#stan-functions-41)
- [**18\.2** Beta Proportion Distribution](https://mc-stan.org/docs/2_22/functions-reference/beta-proportion-distribution.html)
- [**18\.2.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/beta-proportion-distribution.html#probability-density-function-22)
- [**18\.2.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/beta-proportion-distribution.html#sampling-statement-43)
- [**18\.2.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/beta-proportion-distribution.html#stan-functions-42)
- [**19** Circular Distributions](https://mc-stan.org/docs/2_22/functions-reference/circular-distributions.html)
- [**19\.1** Von Mises Distribution](https://mc-stan.org/docs/2_22/functions-reference/von-mises-distribution.html)
- [**19\.1.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/von-mises-distribution.html#probability-density-function-23)
- [**19\.1.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/von-mises-distribution.html#sampling-statement-44)
- [**19\.1.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/von-mises-distribution.html#stan-functions-43)
- [**19\.1.4** Numerical Stability](https://mc-stan.org/docs/2_22/functions-reference/von-mises-distribution.html#numerical-stability)
- [**20** Bounded Continuous Distributions](https://mc-stan.org/docs/2_22/functions-reference/bounded-continuous-distributions.html)
- [**20\.1** Uniform Distribution](https://mc-stan.org/docs/2_22/functions-reference/uniform-distribution.html)
- [**20\.1.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/uniform-distribution.html#probability-density-function-24)
- [**20\.1.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/uniform-distribution.html#sampling-statement-45)
- [**20\.1.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/uniform-distribution.html#stan-functions-44)
- [**21** Distributions over Unbounded Vectors](https://mc-stan.org/docs/2_22/functions-reference/distributions-over-unbounded-vectors.html)
- [**21\.1** Multivariate Normal Distribution](https://mc-stan.org/docs/2_22/functions-reference/multivariate-normal-distribution.html)
- [**21\.1.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/multivariate-normal-distribution.html#probability-density-function-25)
- [**21\.1.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/multivariate-normal-distribution.html#sampling-statement-46)
- [**21\.1.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/multivariate-normal-distribution.html#stan-functions-45)
- [**21\.2** Multivariate Normal Distribution, Precision Parameterization](https://mc-stan.org/docs/2_22/functions-reference/multivariate-normal-distribution-precision-parameterization.html)
- [**21\.2.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/multivariate-normal-distribution-precision-parameterization.html#probability-density-function-26)
- [**21\.2.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/multivariate-normal-distribution-precision-parameterization.html#sampling-statement-47)
- [**21\.2.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/multivariate-normal-distribution-precision-parameterization.html#stan-functions-46)
- [**21\.3** Multivariate Normal Distribution, Cholesky Parameterization](https://mc-stan.org/docs/2_22/functions-reference/multi-normal-cholesky-fun.html)
- [**21\.3.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/multi-normal-cholesky-fun.html#probability-density-function-27)
- [**21\.3.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/multi-normal-cholesky-fun.html#sampling-statement-48)
- [**21\.3.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/multi-normal-cholesky-fun.html#stan-functions-47)
- [**21\.4** Multivariate Gaussian Process Distribution](https://mc-stan.org/docs/2_22/functions-reference/multivariate-gaussian-process-distribution.html)
- [**21\.4.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/multivariate-gaussian-process-distribution.html#probability-density-function-28)
- [**21\.4.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/multivariate-gaussian-process-distribution.html#sampling-statement-49)
- [**21\.4.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/multivariate-gaussian-process-distribution.html#stan-functions-48)
- [**21\.5** Multivariate Gaussian Process Distribution, Cholesky parameterization](https://mc-stan.org/docs/2_22/functions-reference/multivariate-gaussian-process-distribution-cholesky-parameterization.html)
- [**21\.5.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/multivariate-gaussian-process-distribution-cholesky-parameterization.html#probability-density-function-29)
- [**21\.5.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/multivariate-gaussian-process-distribution-cholesky-parameterization.html#sampling-statement-50)
- [**21\.5.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/multivariate-gaussian-process-distribution-cholesky-parameterization.html#stan-functions-49)
- [**21\.6** Multivariate Student-T Distribution](https://mc-stan.org/docs/2_22/functions-reference/multivariate-student-t-distribution.html)
- [**21\.6.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/multivariate-student-t-distribution.html#probability-density-function-30)
- [**21\.6.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/multivariate-student-t-distribution.html#sampling-statement-51)
- [**21\.6.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/multivariate-student-t-distribution.html#stan-functions-50)
- [**21\.7** Gaussian Dynamic Linear Models](https://mc-stan.org/docs/2_22/functions-reference/gaussian-dynamic-linear-models.html)
- [**21\.7.1** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/gaussian-dynamic-linear-models.html#sampling-statement-52)
- [**21\.7.2** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/gaussian-dynamic-linear-models.html#stan-functions-51)
- [**22** Simplex Distributions](https://mc-stan.org/docs/2_22/functions-reference/simplex-distributions.html)
- [**22\.1** Dirichlet Distribution](https://mc-stan.org/docs/2_22/functions-reference/dirichlet-distribution.html)
- [**22\.1.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/dirichlet-distribution.html#probability-density-function-31)
- [**22\.1.2** Meaning of Dirichlet Parameters](https://mc-stan.org/docs/2_22/functions-reference/dirichlet-distribution.html#meaning-of-dirichlet-parameters)
- [**22\.1.3** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/dirichlet-distribution.html#sampling-statement-53)
- [**22\.1.4** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/dirichlet-distribution.html#stan-functions-52)
- [**23** Correlation Matrix Distributions](https://mc-stan.org/docs/2_22/functions-reference/correlation-matrix-distributions.html)
- [**23\.1** LKJ Correlation Distribution](https://mc-stan.org/docs/2_22/functions-reference/lkj-correlation.html)
- [**23\.1.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/lkj-correlation.html#probability-density-function-32)
- [**23\.1.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/lkj-correlation.html#sampling-statement-54)
- [**23\.1.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/lkj-correlation.html#stan-functions-53)
- [**23\.2** Cholesky LKJ Correlation Distribution](https://mc-stan.org/docs/2_22/functions-reference/cholesky-lkj-correlation-distribution.html)
- [**23\.2.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/cholesky-lkj-correlation-distribution.html#probability-density-function-33)
- [**23\.2.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/cholesky-lkj-correlation-distribution.html#sampling-statement-55)
- [**23\.2.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/cholesky-lkj-correlation-distribution.html#stan-functions-54)
- [**24** Covariance Matrix Distributions](https://mc-stan.org/docs/2_22/functions-reference/covariance-matrix-distributions.html)
- [**24\.1** Wishart Distribution](https://mc-stan.org/docs/2_22/functions-reference/wishart-distribution.html)
- [**24\.1.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/wishart-distribution.html#probability-density-function-34)
- [**24\.1.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/wishart-distribution.html#sampling-statement-56)
- [**24\.1.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/wishart-distribution.html#stan-functions-55)
- [**24\.2** Inverse Wishart Distribution](https://mc-stan.org/docs/2_22/functions-reference/inverse-wishart-distribution.html)
- [**24\.2.1** Probability Density Function](https://mc-stan.org/docs/2_22/functions-reference/inverse-wishart-distribution.html#probability-density-function-35)
- [**24\.2.2** Sampling Statement](https://mc-stan.org/docs/2_22/functions-reference/inverse-wishart-distribution.html#sampling-statement-57)
- [**24\.2.3** Stan Functions](https://mc-stan.org/docs/2_22/functions-reference/inverse-wishart-distribution.html#stan-functions-56)
- [*Appendix*](https://mc-stan.org/docs/2_22/functions-reference/appendix.html#appendix)
- [**25** Mathematical Functions](https://mc-stan.org/docs/2_22/functions-reference/math-functions.html)
- [**25\.1** Beta](https://mc-stan.org/docs/2_22/functions-reference/beta-appendix.html)
- [**25\.2** Incomplete Beta](https://mc-stan.org/docs/2_22/functions-reference/inc-beta-appendix.html)
- [**25\.3** Gamma](https://mc-stan.org/docs/2_22/functions-reference/gamma-appendix.html)
- [**25\.4** Digamma](https://mc-stan.org/docs/2_22/functions-reference/digamma-appendix.html)
- [*References*](https://mc-stan.org/docs/2_22/functions-reference/references.html#references)
# [Stan Functions Reference](https://mc-stan.org/docs/2_22/functions-reference/)
This is an old version, [view current version](https://mc-stan.org/docs/functions-reference/continuous_distributions_on_0_1.html#beta-distribution).
## 18\.1 Beta Distribution
### 18\.1.1 Probability Density Function
If α∈R\+ α ∈ R \+ and β∈R\+ β ∈ R \+, then for θ∈(0,1) θ ∈ ( 0 , 1 ), Beta(θ\|α,β)\=1B(α,β)θα−1(1−θ)β−1, Beta ( θ \| α , β ) \= 1 B ( α , β ) θ α − 1 ( 1 − θ ) β − 1 , where the beta function B() B ( ) is as defined in section [combinatorial functions](https://mc-stan.org/docs/2_22/functions-reference/betafun.html#betafun).
***Warning:*** If θ\=0 θ \= 0 or θ\=1 θ \= 1, then the probability is 0 and the log probability is −∞ − ∞. Similarly, the distribution requires strictly positive parameters, α,β\>0 α , β \> 0.
### 18\.1.2 Sampling Statement
`theta ~` **`beta`**`(alpha, beta)`
Increment target log probability density with `beta_lpdf(theta | alpha, beta)` dropping constant additive terms.
### 18\.1.3 Stan Functions
`real` **`beta_lpdf`**`(reals theta | reals alpha, reals beta)`
The log of the beta density of `theta` in \[0,1\] \[ 0 , 1 \] given positive prior successes (plus one) alpha and prior failures (plus one) beta
`real` **`beta_cdf`**`(reals theta, reals alpha, reals beta)`
The beta cumulative distribution function of `theta` in \[0,1\] \[ 0 , 1 \] given positive prior successes (plus one) alpha and prior failures (plus one) beta
`real` **`beta_lcdf`**`(reals theta | reals alpha, reals beta)`
The log of the beta cumulative distribution function of `theta` in \[0,1\] \[ 0 , 1 \] given positive prior successes (plus one) alpha and prior failures (plus one) beta
`real` **`beta_lccdf`**`(reals theta | reals alpha, reals beta)`
The log of the beta complementary cumulative distribution function of `theta` in \[0,1\] \[ 0 , 1 \] given positive prior successes (plus one) alpha and prior failures (plus one) beta
`R` **`beta_rng`**`(reals alpha, reals beta)`
Generate a beta variate with positive prior successes (plus one) alpha and prior failures (plus one) beta; may only be used in transformed data and generated quantities blocks. For a description of argument and return types, see section [vectorized PRNG functions](https://mc-stan.org/docs/2_22/functions-reference/vectorization.html#prng-vectorization). |
| Readable Markdown | ### Probability Density Function
If α ∈ R \+ and β ∈ R \+, then for θ ∈ ( 0 , 1 ), Beta ( θ \| α , β ) \= 1 B ( α , β ) θ α − 1 ( 1 − θ ) β − 1 , where the beta function B ( ) is as defined in section [combinatorial functions](https://mc-stan.org/docs/2_22/functions-reference/betafun.html#betafun).
***Warning:*** If θ \= 0 or θ \= 1, then the probability is 0 and the log probability is − ∞. Similarly, the distribution requires strictly positive parameters, α , β \> 0.
### Sampling Statement
`theta ~` **`beta`**`(alpha, beta)`
Increment target log probability density with `beta_lpdf(theta | alpha, beta)` dropping constant additive terms.
### Stan Functions
`real` **`beta_lpdf`**`(reals theta | reals alpha, reals beta)`
The log of the beta density of `theta` in \[ 0 , 1 \] given positive prior successes (plus one) alpha and prior failures (plus one) beta
`real` **`beta_cdf`**`(reals theta, reals alpha, reals beta)`
The beta cumulative distribution function of `theta` in \[ 0 , 1 \] given positive prior successes (plus one) alpha and prior failures (plus one) beta
`real` **`beta_lcdf`**`(reals theta | reals alpha, reals beta)`
The log of the beta cumulative distribution function of `theta` in \[ 0 , 1 \] given positive prior successes (plus one) alpha and prior failures (plus one) beta
`real` **`beta_lccdf`**`(reals theta | reals alpha, reals beta)`
The log of the beta complementary cumulative distribution function of `theta` in \[ 0 , 1 \] given positive prior successes (plus one) alpha and prior failures (plus one) beta
`R` **`beta_rng`**`(reals alpha, reals beta)`
Generate a beta variate with positive prior successes (plus one) alpha and prior failures (plus one) beta; may only be used in transformed data and generated quantities blocks. For a description of argument and return types, see section [vectorized PRNG functions](https://mc-stan.org/docs/2_22/functions-reference/vectorization.html#prng-vectorization). |
| Shard | 18 (laksa) |
| Root Hash | 17466047053846532618 |
| Unparsed URL | org,mc-stan!/docs/2_22/functions-reference/beta-distribution.html s443 |