7 Outputs
7.3 Screen Output
As Marxan runs, some output can be provided on the screen. This output can be used to check on how the program is running and to give a brief summary of the solutions. It can also give you an idea of how long a single run takes and from there you can gauge how long it will take to finish all runs for that scenario (e.g., if it takes one minute to complete a single run, then it will take approximately 100 minutes to complete 100 runs).
There are different levels of information that can be requested for the screen output; the level requested is termed the verbosity level (See Figure 11 and 12). Users can choose between the four verbosity levels: 0 (Silent Running), 1 (Results Only), 2 (General Progress), and 3 (Detailed Progress). The chosen level is set using the VERBOSITY variable in the Input Parameter File.
Note that you can save the screen output as an output file, called Screen Log File (see Section 7.4.9), to look at it after Marxan has finished running.
7.3.1 Silent Running
If the verbosity level is set to ‘Silent Running’ (verbosity level 0), then no information about the scenario will be displayed on the screen. This option should only be used if you are confident in Marxan execution and if you are saving all necessary outputs.
Marxan User Manual 7-71 7.3.2 Results Only
When ‘Results Only’ (verbosity level 1) is selected, the screen will display the run numbers and the time it took to generate all runs. Each run number will appear on the screen as Marxan generates a final solution for that run (Figure 11). No other information regarding each run is provided.
Figure 11. Example of the on screen provided using verbosity 1 (Results Only)
7.3.3 General Progress
‘General Process’ (verbosity level 2) is the default setting for the screen output and is recommended for most cases. If the screen output is set to either ‘General Progress’ or
‘Detailed Progress’ (verbosity level 3; see below), then the following summaries will be provided (see Figure 12).
1. Details of the data being entered;
2. The run number and the annealing parameters calculated during pre-processing (if adaptive annealing is being used);
3. The details of the initial or seed reserve system;
4. Results of the final solution from that run (the basic summary information for each run are described in
5. Table 8).
6. An output used by Marxan to quickly sort through all runs to determine which one
Marxan User Manual 7-72 gave the ‘best’ solution.
Figure 12. Example of the on screen provided using verbosity level 2 and 3 (General Progress and Detailed Progress)
Table 8. Basic summary information of each run Information Description
Run The number of the repeat run (e.g., Run 1, Run 2, Run 3, etc.) Value The overall objective function value for the solution
Cost The total cost of the reserve system as determined solely by the costs given to each planning unit
PUs The number of planning units (PUs) contained in the solution Boundary The total boundary length of the reserve system
Missing The number of conservation features that did not achieve their targets in the final solution
Shortfall The amount by which the targets for conservation features have not been met in the solution
Penalty The penalty that was added to the objective function when the reserve system failed to meet the representation targets for all features
This level of information can be particularly useful for a few reasons. First, if you a running
Marxan User Manual 7-73 more than one optimisation procedure (i.e. simulated annealing followed by iterative improvement, see Appendix B-2), then it allows you to get a feel for how much work each of the different procedures is doing. For instance, if most of the gains in reserve value and target achievement are being made in the iterative improvement phase, you know that either the annealing parameters or the penalties need alteration. Second, if you want to begin using a fixed annealing schedule, this output can give you an idea of the sort of values Marxan is calculating using its adaptive annealing module (see Appendix B-2.1.1). Finally, if you have set some constraints on the initial reserve system, for example by including existing protected areas, this output will quickly confirm that this information is being included and the value of the existing reserves in terms of meeting your objectives.
7.3.4 Detailed Progress
‘Detailed Progress’ (verbosity level 3) will display the same screen as ‘General Progress’, but it will also generate the text file, ‘DebugTraceFile_MarOpt’. This file will appear in the same file location as the Marxan executable file. The detailed information in the file shows exactly what the program did during each run. It can be used to confirm that the algorithm has run as it should and has not ‘stalled’. It can also help identify certain problems (e.g., if the numbers do not change and it is “stalled”) as it allows the user to track the annealing progress in detail. For this reason, some users prefer to use this setting to visually check that the program appears to be running well. In most cases, however, this level of detail is unnecessary. Furthermore, this verbosity level may lengthen the processing time.