# Importing APSIM Classic and NewGeneration files

#### Rai Schwalbert & Adrian Correndo

#### 2026-03-18

## 1. Introduction

The `metrica` package was developed to assess the prediction performance of, among other, crop simulation models such as APSIM.

This vignette introduces the functionality of the `metrica` package applied to facilitate opening APSIM output files in R.

## Import data from APSIM

### 1. APSIM Classic (.out)

    # Obtaining filepath from package folder
    apsim_out_filepath <- system.file("extdata/soybean.out", package = "metrica")

    # Use import_apsim_out for APSIM Classic output
    soybean.out <- metrica::import_apsim_out(filepath = apsim_out_filepath)

    head(soybean.out)

### 2. APSIM NextGeneration (.db)

    # Obtaining path from package folder
    apsim_db_folderpath <- system.file("extdata", package = "metrica")

    # Use import_apsim_db for APSIM NextGeneration output
    soybean.db <- metrica::import_apsim_db(filename = "soybean.example.db", folder = apsim_db_folderpath)

    head(soybean.db)

    # If observed.data is already as a dataframe, the user may do the match using a simple code like this:
    # PO.dataframe <- simulated.data %>% left_join(., observed.data) *by = "col" arg. could be required*