e2ep_extract_start {StrathE2EPolar} | R Documentation

## Extract the values of all the state variables at the end of a model run and format for use as new initial conditions.

### Description

The function saves the state of the model at the end of a run (using the e2ep_run() function) for use as initial conditions in future runs. This enables, for example, the model to be run for a long time to attain a stationary state, and then restarted in that state.

### Usage

    e2ep_extract_start(model, results, csv.output = TRUE)

### Arguments

`model` | R-list object defining the model configuration compiled by the e2ep_read() function.
`results` | R-list object generated by the e2ep_run() function.
`csv.output` | Logical. If TRUE then enable writing of csv output files (default=FALSE).

### Details

Initial conditions for a model run are held in the /Param folder of the Model/Variant path specified in the e2ep_read() function call used to define a run. By default, the function attampts to write the model end-state file back to this /Param folder. However, the package folders are read-only so if e2ep_read() has been specified to load an internally provided Model/Variant then the output will revert to the currently specified results folder instead. To fix this, copy the required package model to a user workspace using the e2ep_copy() function and re-run.

The new initial conditions file will have a name initial_values-*.csv, where * is the model.ident text identifier specified in e2ep_read() To source the new initial conditions in a subsequent model run, edit the MODEL_SETUP.csv file in the required /Models/Variant folder

### Value

Table of state variable values from the end of a run formatted as required for input to a new model run as initial conditions. By selecting csv.output=TRUE these data are also returned as a csv file to the Param folder of the current model, unless this is one of the Barents Sea model versions within the package.

### See Also

`e2ep_read`, `e2ep_run`

### Examples

    # Example which generates an initial values object from an internal Barents Sea model but
    # does not attempt to save it back to the Parameters folder of the model setup. Just
    # run for 1 year in this example:
        model <- e2ep_read("Barents_Sea", "2011-2019")
        results <- e2ep_run(model, nyears=1)
        new_initial <- e2ep_extract_start(model,results,csv.output=FALSE)
        new_initial

    # Dummy example to illustrate the process of saving initial values
    # data back into the model Param folder:
    # Assumes that the model setup is held in models.path="Folder/Models". Replace this
    # with your own relative path to your user library of models:
    #    model <- e2ep_read("Modelname","Variantname",models.path="Folder/Models",model.ident="new")
    #    results <- e2ep_run(model, nyears=30)
    #    new_initial <- e2ep_extract_start(model,results,csv.output=TRUE)
    # The new initial values file will be written back into Folder/Models/Param with
    # the identitifer "new"

[Package StrathE2EPolar version 2.1.0 Index]