compare_model_output: Compare new and stored results for a BioCro model test case

Description

BioCro models can be tested using test cases, which are sets of known outputs that correspond to particular inputs. The compare_model_output function facilitates manual comparisons between new and stored results.

Note that model tests are distinct from the module tests described in module_testing.

Usage

compare_model_output(mtc, columns_to_keep = NULL)

Value

A data frame as described above.

Arguments

mtc: A single module test case, which should be created using model_test_case.
columns_to_keep: A vector of column names that should be included in the return value. If columns_to_keep is NULL, all columns that are in both the new and stored result will be included.

Details

The compare_model_output function is a key part of the BioCro model testing system. See model_testing for more information.

This function will run the model to get a new result, and load the stored result associated with the test case. The two data frames will be combined using rbind, where a new column named version indicates whether each row is from the new or stored result.

It is intended that quantities from the resulting data frame will be plotted to visually look for changes in the model output.

Examples

Run this code

# Define a test case for the miscanthus model and save the model output to a
# temporary directory
miscanthus_test_case <- model_test_case(
    'miscanthus_x_giganteus',
    miscanthus_x_giganteus,
    get_growing_season_climate(weather$'2005'),
    TRUE,
    tempdir()
)

update_stored_model_results(miscanthus_test_case)

# Now we can use `compare_model_output` to compare the saved result to a new one
comparison_df <- compare_model_output(miscanthus_test_case)

# This will be a boring example because the new and stored results will be
# exactly the same
lattice::xyplot(
  Leaf + Stem + Root ~ time,
  group = version,
  data = comparison_df,
  type = 'l',
  auto = TRUE,
  grid = TRUE
)