1274 normalizing of exposure rate

[DavidKerkmann]

Changes and Information

Please briefly list the changes (main added features, changed items, or corrected bugs) made:

• Adds a cache for the number of persons per cell and age group.
• Uses this cache to normalize the exposure rate according to the number of persons inside a cell.

If need be, add additional information and what the reviewer should look out for in particular:

Merge Request - Guideline Checklist

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Checks by code author

• Every addressed issue is linked (use the "Closes #ISSUE" keyword below)
• New code adheres to coding guidelines
• No large data files have been added (files should in sum not exceed 100 KB, avoid PDFs, Word docs, etc.)
• Tests are added for new functionality and a local test run was successful (with and without OpenMP)
• Appropriate documentation for new functionality has been added (Doxygen in the code and explanations in the online documentation)
• Proper attention to licenses, especially no new third-party software with conflicting license has been added
• (For ABM development) Checked benchmark results and ran and posted a local test above from before and after development to ensure performance is monitored.

Checks by code reviewer(s)

• Corresponding issue(s) is/are linked and addressed
• Code is clean of development artifacts (no deactivated or commented code lines, no debugging printouts, etc.)
• Appropriate unit tests have been added, CI passes, code coverage and performance is acceptable (did not decrease)
• No large data files added in the whole history of commits(files should in sum not exceed 100 KB, avoid PDFs, Word docs, etc.)
• On merge, add 2-5 lines with the changes (main added features, changed items, or corrected bugs) to the merge-commit-message. This can be taken from the briefly-list-the-changes above (best case) or the separate commit messages (worst case).

[codecov]

Codecov Report

❌ Patch coverage is 93.33333% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 97.24%. Comparing base (2defe8b) to head (c8af250).
⚠️ Report is 28 commits behind head on main.

Files with missing lines	Patch %	Lines
cpp/models/abm/model.cpp	89.47%	2 Missing ⚠️
cpp/models/abm/model.h	85.71%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1322      +/-   ##
==========================================
- Coverage   97.37%   97.24%   -0.13%     
==========================================
  Files         174      176       +2     
  Lines       15024    15517     +493     
==========================================
+ Hits        14630    15090     +460     
- Misses        394      427      +33     

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[DavidKerkmann]

Performance benchmarks:

Main:

----------------------------------------------------------------------------------
Benchmark                                        Time             CPU   Iterations   
----------------------------------------------------------------------------------   
abm_benchmark/abm_benchmark_50k               3385 ms         3344 ms            1   
abm_benchmark/abm_benchmark_50k               3295 ms         3297 ms            1   
abm_benchmark/abm_benchmark_50k               3263 ms         3266 ms            1   
abm_benchmark/abm_benchmark_50k               2805 ms         2812 ms            1   
abm_benchmark/abm_benchmark_50k               2678 ms         2672 ms            1   
abm_benchmark/abm_benchmark_50k_mean          3085 ms         3078 ms            5   
abm_benchmark/abm_benchmark_50k_median        3263 ms         3266 ms            5   
abm_benchmark/abm_benchmark_50k_stddev         320 ms          312 ms            5   
abm_benchmark/abm_benchmark_50k_cv           10.38 %         10.13 %             5   
abm_benchmark/abm_benchmark_100k              5681 ms         5656 ms            1
abm_benchmark/abm_benchmark_100k              5543 ms         5547 ms            1   
abm_benchmark/abm_benchmark_100k              5661 ms         5641 ms            1   
abm_benchmark/abm_benchmark_100k              5646 ms         5625 ms            1   
abm_benchmark/abm_benchmark_100k              5558 ms         5562 ms            1   
abm_benchmark/abm_benchmark_100k_mean         5618 ms         5606 ms            5   
abm_benchmark/abm_benchmark_100k_median       5646 ms         5625 ms            5   
abm_benchmark/abm_benchmark_100k_stddev       62.8 ms         48.7 ms            5   
abm_benchmark/abm_benchmark_100k_cv           1.12 %          0.87 %             5   
abm_benchmark/abm_benchmark_200k             11441 ms        11422 ms            1
abm_benchmark/abm_benchmark_200k             11210 ms        11203 ms            1   
abm_benchmark/abm_benchmark_200k             11385 ms        11391 ms            1   
abm_benchmark/abm_benchmark_200k             11394 ms        11391 ms            1   
abm_benchmark/abm_benchmark_200k             11263 ms        11250 ms            1   
abm_benchmark/abm_benchmark_200k_mean        11338 ms        11331 ms            5   
abm_benchmark/abm_benchmark_200k_median      11385 ms        11391 ms            5   
abm_benchmark/abm_benchmark_200k_stddev       97.3 ms         97.8 ms            5   
abm_benchmark/abm_benchmark_200k_cv           0.86 %          0.86 %             5

This branch:

----------------------------------------------------------------------------------
Benchmark                                        Time             CPU   Iterations
----------------------------------------------------------------------------------
abm_benchmark/abm_benchmark_50k               2811 ms         2812 ms            1
abm_benchmark/abm_benchmark_50k               2807 ms         2797 ms            1
abm_benchmark/abm_benchmark_50k               2811 ms         2812 ms            1
abm_benchmark/abm_benchmark_50k               2829 ms         2828 ms            1
abm_benchmark/abm_benchmark_50k               2869 ms         2875 ms            1
abm_benchmark/abm_benchmark_50k_mean          2826 ms         2825 ms            5
abm_benchmark/abm_benchmark_50k_median        2811 ms         2812 ms            5
abm_benchmark/abm_benchmark_50k_stddev        25.8 ms         30.1 ms            5
abm_benchmark/abm_benchmark_50k_cv            0.91 %          1.06 %             5
abm_benchmark/abm_benchmark_100k              5884 ms         5891 ms            1
abm_benchmark/abm_benchmark_100k              6169 ms         6156 ms            1
abm_benchmark/abm_benchmark_100k              5948 ms         5953 ms            1
abm_benchmark/abm_benchmark_100k              6141 ms         6141 ms            1
abm_benchmark/abm_benchmark_100k              5919 ms         5906 ms            1
abm_benchmark/abm_benchmark_100k_mean         6012 ms         6009 ms            5
abm_benchmark/abm_benchmark_100k_median       5948 ms         5953 ms            5
abm_benchmark/abm_benchmark_100k_stddev        133 ms          129 ms            5
abm_benchmark/abm_benchmark_100k_cv           2.21 %          2.15 %             5
abm_benchmark/abm_benchmark_200k             11953 ms        11938 ms            1
abm_benchmark/abm_benchmark_200k             12382 ms        12359 ms            1
abm_benchmark/abm_benchmark_200k             11937 ms        11906 ms            1
abm_benchmark/abm_benchmark_200k             11564 ms        11562 ms            1
abm_benchmark/abm_benchmark_200k             11668 ms        11656 ms            1
abm_benchmark/abm_benchmark_200k_mean        11901 ms        11884 ms            5
abm_benchmark/abm_benchmark_200k_median      11937 ms        11906 ms            5
abm_benchmark/abm_benchmark_200k_stddev        317 ms          310 ms            5
abm_benchmark/abm_benchmark_200k_cv           2.67 %          2.61 %             5

[reneSchm]

Nice addition! There is only one issue with the normalization in build_exposure_caches, that makes it possible to use uninitialized population caches through Model::interact.
The other requests are only minor adjustments.