# aging.prefatt.game

##### Generate an evolving random graph with preferential attachment and aging

This function creates a random graph by simulation its evolution. Each time a new vertex is added it creates a number of links to old vertices and the probability that an old vertex is cited depends on its in-degree (preferential attachment) and age.

- Keywords
- graphs

##### Usage

`aging.prefatt.game(n, m=1, aging.type="exponential", params=list(), ...)`

##### Arguments

- n
- The number of vertices in the graph.
- m
- The number of edges each new vertex creates (except the very first vertex.
- aging.type
- Character string, the type of the function giving probability that an old vertex is cited depending on its age. See details below.
- params
- Named list, this gives the parameters of the
aging function selected by the`aging.type`

argument. See details below. - ...
- Additional arguments, these are passed to the graph constructor.

##### Details

This is discrete time step model, in each time step a new vertex is
added to the network. The new vertex cites a number (parameter
`m`

) of other vertices. The probability that a vertex is cited is
proportional to the product of the in-degree of the node plus one and
the so-called aging function (`aging.type`

arguments).

The `exponential`

aging function decreases exponetially with age
with exponent `aging.exp`

, its only parameter.

The `powerlaw`

aging function decreases as a power law with age,
the exponent is given by the `aging.exp`

parameter.

##### Value

- A new graph.

##### See Also

##### Examples

```
g <- aging.prefatt.game(100, aging.type="exponential",
params=list(aging.exp=1/100))
g2 <- aging.prefatt.game(100, aging.type="powerlaw",
params=list(aging.exp=1))
```

*Documentation reproduced from package igraph, version 0.1.2, License: GPL version 2 or later (June, 1991)*