Distance Calculation Comparison

This is a comparison between the two methods of distance calculations in OpenSHA.

The two options (both in LocationUtils.java are linearDistance (referred to as "slow") and linearDistanceFast (referred to as "fast").

Test conducted with this class: trunk/dev/scratch/kevin/DistSpeedTest.java

For full results, see attachment dist_calc_comparison.xlsx

Test Results

• Distance calculations: 5000000
• Distance range: 0.001 KM -> 5000 KM, 0.001 KM increments from starting location with azimuth of 45 degrees.
• Total times
  • Fast: 5463 milis = 5.463 secs (0.0010926 milis/calc)
  • Slow: 7410 milis = 7.410 secs (0.001482 milis/calc)
• Speedup: 1.356397583745195 x

distance	dist delta (fast - slow)	percent difference
50 KM	1.28E-04 KM	2.57E-04 %
100 KM	0.001026994 KM	0.001027005 %
200 KM	0.008215952 KM	0.004108145 %
500 KM	0.128369704 KM	0.025680531 %
1000 KM	1.026777967 KM	0.102783287 %
2000 KM	8.207860832 KM	0.412083308 %
3000 KM	27.66526207 KM	0.930752669 %
4000 KM	65.46170846 KM	1.663744154 %
5000 KM	127.6116548 KM	2.61896699 %

Charts

Total cumulative calculation time over iterations

Distance delta (fast distance - slow distance) vs calculation distance

Percent difference between fast and slow methods vs calculation distance