Move MAgPIE coupling between the Nash iterations

[dklein-pik]

Purpose of this PR

This PR replaces the previous coupling, in which REMIND and MAgPIE run sequentially, with shifting the MAgPIE runs between the Nash iterations. start_bundle_coupled.R and start_coupled.R have been removed. Use start.R together with a scenario_config_magpie*.csv file (formerly known as scenario_config_coupled.csv) to activate the MAgPIE coupling, e.g.

Rscript start.R config/scenario_config_magpie.R

The new coupling is mainly perforemd in core/presolve.gms, by calling an external R script, that transfers the data of the latest Nash solution to MAgPIE, runs MAgPIE, and transfers the MAgPIE data to a magpieData.gdx, which is then read by GAMS.

If you need to continue runs to yield a better convergence, paste the path to a previous REMIND or MAgPIE report into the column continueFromHere in the scenario_config_magpie.csv and start the respective scenario.

Create convergence plots for individual runs with

Rscript output.R -> single -> plotRemMagNash.R

and for continued runs with

Rscript output.R -> comparison -> plotRemMagNash.R

Leftorvers

• add test for new coupled mode (old test_20-coupled.R does not work with the new coupling and has been removed)
• this requires: make empty_magpie work
• update documentation in the tutorials folder
• add path_gdx and friends to coupled config and evaluate in start.R
• adapt configureCfg L58ff such that it finds the right precursor, i.e. it looks for C_ runs
• make referencing another run by name work for path_mif_ghgprice_land
• use short reporting for MAgPIE to save time, use full reporting in last iteration

Type of change

Parts concerned

• ☑️ GAMS Code
• ☑️ R-scripts
• ◻️ Documentation (GAMS incode documentation, comments, tutorials)
• ◻️ Input data / CES parameters
• ◻️ Tests, CI/CD (continuous integration/deployment)
• ☑️ Configuration (switches in main.gms, default.cfg, and scenario_config*.csv files)
• ◻️ Other (please give a description)

Impact

• ◻️ Bug fix
• ☑️ Refactoring
• ☑️ New feature
• ◻️ Change of parameter values or input data (including CES parameters)
• ◻️ Minor change (default scenarios show only small differences)
• ◻️ Fundamental change of results of default scenarios

Checklist

• I executed the automated model tests (make test) after my final commit and all tests pass (FAIL 0)
• I adjusted the reporting in remind2 if and where it was needed
• I adjusted the madrat packages (mrremind and other packages involved) for input data generation if and where it was needed
• My code follows the coding etiquette
• I explained my changes within the PR, particularly in hard-to-understand areas
• I checked that the in-code documentation is up-to-date
• I adjusted forbiddenColumnNames in readCheckScenarioConfig.R in case the PR leads to deprecated switches
• I updated the CHANGELOG.md correctly (added, changed, fixed, removed, input data/calibration)

Further information (optional)

• Runs with these changes are here: /p/tmp/dklein/remMagNash-Comp/
• Comparison of results: old versus new coupling
  Results are almost identical. Differences are due to slightly different solution paths, since in the old coupling REMIND is running multiple times, each time restarting not exactly where it left (e.g. co2 prices in the initial Nash iterations), whereas in the new coupling the next Nash iteration continues exactly where the old left (except for the variables that are exchanged in the couping).

[LaviniaBaumstark]

thanks for all the comments and documentation!

[LaviniaBaumstark]

thanks!