# Merging simulation outputs¶

## Introduction¶

Simulations can be merged using the Merger class. Here, multiple simulations are combined into a single database, with each simulation being associated with a particular “guild”. These guilds could represent different environmental niches, body sizes or other differentiating factors.

## Usage¶

Add simulations using add_simulation() and then use write().

Previously calculated metrics are all stored in *_GUILDS tables. Species identities are preserved (without allowing for a species to exist in more than one guild), meaning all metrics can be re-calculated using apply() and functions such as calculate_richness(). Alternatively, use add_simulations()

merger = Merger("output.db")