## risk.ArchimedeanCopula


An exchangeable Archimedean copula: Clayton, Gumbel, Frank or Joe.


Usage


``` python
risk.ArchimedeanCopula()
```


## Parameters


`family: (clayton, gumbel, frank, joe) = ``"clayton"`  

`theta: float`  
Positive for Clayton and Frank; at least 1 for Gumbel and Joe.

`dim: int`  


## Raises


`ValueError`  
If the family is unknown or [theta](reserving.ClarkFit.md#prospicio.reserving.ClarkFit.theta) is out of range.


## Examples

``` python
>>> from prospicio.risk import ArchimedeanCopula
>>> c = ArchimedeanCopula("clayton", 2.0, 3)  # Kendall's tau 0.5
>>> c.dim, c.family
```

(3, 'clayton')


## Attributes

| Name | Description |
|----|----|
| [dim](#dim) | Number of dimensions. |
| [family](#family) | Family name. |
| [theta](#theta) | Copula parameter. |

------------------------------------------------------------------------


#### dim


Number of dimensions.


`dim: int`


------------------------------------------------------------------------


#### family


Family name.


`family: str`


------------------------------------------------------------------------


#### theta


Copula parameter.


`theta: float`


## Methods

| Name | Description |
|----|----|
| [sample()](#sample) | [n](distributions.Binomial.md#prospicio.distributions.Binomial.n) draws of uniforms; draw `i` uses stream `i` of [seed](aggregate.EventSet.md#prospicio.aggregate.EventSet.seed). |

------------------------------------------------------------------------


#### sample()


[n](distributions.Binomial.md#prospicio.distributions.Binomial.n) draws of uniforms; draw `i` uses stream `i` of [seed](aggregate.EventSet.md#prospicio.aggregate.EventSet.seed).


Usage


``` python
sample(n, seed)
```


##### Parameters


`n: int`  

`seed: int`  


##### Returns


`list of list of float`