Tr0py/cpp-lean

PHAS0100Assignment2

author: troppingz@gmail.com

Build and Run

Using CMAKE and MAKEFILE to compile program

mkdir build
cd build
cmake ..
make -j4

Using CTEST to test correctness

ctest

the results should be

❯ ctest
Test project /home/tropping/CProg/cpp-ucl/PHAS0100Assignment2/build
    Start 1: NoArgs
1/3 Test #1: NoArgs ...........................   Passed    0.00 sec
    Start 2: 1File
2/3 Test #2: 1File ............................   Passed    0.00 sec
    Start 3: SolarTest
3/3 Test #3: SolarTest ........................   Passed    0.43 sec

100% tests passed, 0 tests failed out of 3

Total Test time (real) =   0.45 sec

Testing Solar System Simulator

❯ ./bin/solarSystemSimulator

Expected output:

❯ ./bin/solarSystemSimulator
Sun
 2.24622e+07
-3.59523e+07
     -409040
Mercury
-3.15416e+12
 4.76552e+12
 6.78703e+11
Venus
 1.26497e+12
 1.61415e+12
-5.08634e+10
Earth
 2.02418e+11
-1.09416e+12
 6.56107e+07
Mars
-1.94388e+11
-4.30279e+11
-4.24283e+09
Jupiter
-2.46602e+10
 3.32954e+10
 4.13088e+08
Saturn
-5.90437e+09
 9.08739e+09
 7.68755e+07
Uranus
-2.17094e+09
 -1.7081e+09
 2.18026e+07
Neptune
-1.17952e+09
 2.44949e+08
 2.21375e+07
rcom =
 -38.5867
  20.6385
-0.417103
ptotal =
-724743
 387636
-7834.1
mtotal = 5.92326e+11
CPU time used: 7.01 s
Wall clock time passed: 1.78 s

Result screenshot

Timestep and Runtime Trade-off & Parallel Speedup

Machine Info:

• CPU: Intel(R) Core(TM) i5-4590 CPU @ 3.30GHz, with 4 cores
• Memory: 12GB
• OMP_NUM_THREADS=4

Time Step (year)	CPU Time(s)	Wall Clock Time(s)	Final $r_{com}$	Final $p_{total}$	Parallel CPU Time(s)	Parallel Wall Clock Time(s)	Speedup
0.000274	0.45571	0.45583	-38.5899 20.6402 -0.417136	-724743 387636 -7834.1	0.75	0.20	2.27
0.0000274	4.56640	4.56655	-38.5867 20.6385 -0.417103	-724743 387636 -7834.1	7.03	1.78	2.56
0.00000274	46.45	46.46	-38.5861 20.6382 -0.417096	-724743 387636 -7834.1	71.41	18.22	2.54
0.000001	124.86	124.92	-38.5861 20.6382 -0.417095	-724743 387636 -7834.1	199.12	51.27	2.43
0.0000005	259.18	259.24	-38.586 20.6382 -0.417095	-724743 387637 -7834.1	423.61	113.09	2.29