ssir {ATQ} | R Documentation |

## Stochastic SIR simulation

### Description

This function runs a stochastic Susceptible-Infectious-Removed (SIR) epidemic simulation. It can run a single simulation or multiple replications. Also simulates laboratory confirmed cases

### Usage

```
ssir(
N,
T = 300,
alpha,
avg_start = 45,
min_start = 20,
inf_period = 4,
inf_init = 32,
report = 0.02,
lag = 7,
rep = NULL
)
```

### Arguments

`N` |
Numeric. The total population size. |

`T` |
Numeric. The duration of the simulation in time steps. Default is 300. |

`alpha` |
Numeric. The transmission rate. Must be a number between 0 and 1. |

`avg_start` |
Numeric. The average start day of the epidemic. Default is 45. |

`min_start` |
Numeric. The minimum start day of the epidemic. Default is 20. |

`inf_period` |
Numeric. The duration of the infectious period in time steps. Default is 4. |

`inf_init` |
Numeric. The initial number of infected individuals. Default is 32. |

`report` |
Numeric. The proportion of cases that are reported. Default is 0.02. |

`lag` |
Numeric. The average delay in reporting cases. Default is 7. |

`rep` |
Numeric or NULL. The number of simulation replications to run. If NULL or 1, a single simulation is run. |

### Value

If rep is NULL or 1, returns an object of class "ssir_epidemic" containing:

`new_inf` |
Vector of new infections at each time step |

`reported_cases` |
Vector of reported cases at each time step |

`S` |
Vector of susceptible individuals at each time step |

`I` |
Vector of infectious individuals at each time step |

`R` |
Vector of removed individuals at each time step |

`parameters` |
List of input parameters |

If rep > 1, returns an object of class "ssir_epidemic_multi" containing multiple simulation results.

### Examples

```
# Run a single simulation
result <- ssir(N = 10000, T = 300, alpha = 0.3, inf_period = 4,
inf_init = 32, report = 0.02, lag = 7)
# Run multiple simulations
multi_result <- ssir(N = 10000, T = 300, alpha = 0.3, inf_period = 4, inf_init = 32,
report = 0.02, lag = 7, rep = 100)
```

*ATQ*version 0.2.2 Index]